Alison Tranny Retarder vs Jake Brake

[Gary & Peggy Stevens]

We test drove an 01 Liberty Classic Lady when we were in Florida last week, and it had the Alison 6 Speed Transmission Retarder. I just loved it.

What is better, Jake Brake, Tranny Retarder and why?

Can you guys give me the pros and cons of having one or the other, please so I can either rule out trying to find a used bus with one or the other in it?

Gary:confused:

[Orren Zook]

Well, you'd never have to worry about the dreaded 'no engine brake' signs with the trans retarder.... I've always had Pac or Jacobs exhaust braking on my diesel coaches and it has worked well, plus I like the noise they make. I understand that the fluid temperatures need more monitoring with the retarder because of how it works.

[MangoMike]

Gary,

I have the retarder on the Liberty and it works fine, although you really have to pay attention to the transmission fluid temperature as it's easy to exceed 230 on some hills. You'll probably fine the concesus being the jake is better. That being said it would be pretty far down my list of considerations for the "perfect" bus.

Mike

[dreadnought]

I was temporarily brain dead and pricing a new Liberty
earlier this year. Was told all new buses come standard with retarders and a Jake would lower the price by 6 grand! I can't understand why anyone would pay an extra 6K to boil their tranny oil. Jakes have been around forever, work great and are just about bullet proof. My old used bus came w/the retarder, works ok, but I can't help feeling there's a plot involved to sell transmissions.

[Jon Wehrenberg]

We had a Jake on the first coach and have a retarder on our current coach.

This is strictly an opinion so take it for what it is worth. We would never again want a coach with a retarder. Our reasons are fairly simple. The Jake does not have an adverse affect on anything. It does not raise temperatures so using it at its full setting constantly does not require anything of the driver.

The retarder seems to have more holding power. It has a broader range of retarding power than a Jake so you can select a retarding force suited for the hill, and if the retarder is on, applying the brakes also adds retarder force to assist with braking. When using brakes heavily with the retarder on will drive the temperature up rapidly.

As Mike points out, it heats up the transmission. Heat will damage the transmission fluid and the transmission, so for those who have a coach with a retarder and a transmission temperature gauge you have to monitor the temperatures. For those with newer coaches, Prevost allows you to monitor the transmission temperatures, but you have to go through some gyrations to get at that information through the Pro-Driver. Maybe Prevost feels ignorance is bliss so they eliminated the temperature gauge on the new dash.

I have no clue what a safe transmission oil temperature is because there are no limits that I can find defined anywhere. I arbitrarily use 230 degrees just because the red line for oil on my plane is 240. If someone knows what the real limit should be please post it.

This is an observation but with all the sensors and computer power now in place it seems to me that if the temperatures get too high, the computer could reduce the retarding force until temperatures return to a normal range, but the flip side of that is that Allison and Prevost will spend a lot of time in court because any time braking or retarding force is reduced it could have dire consequences.

[truk4u]

Ditto Jon's comment.. I've had both and with a previous Foretravel running out west in the real mountains, the trans temps where a real concern with the retarder. Go with the Jake, it's bullet proof!

[rvbus01]

Retarder Operation -- How Does It Work?


The retarder is at the output of the transmission and consists of a vaned cavity and a vaned rotor which is splined to and driven by the output shaft. When the retarder is activated, fluid is directed into the retarder cavity. The interaction of the fluid with the rotating and stationary vanes causes the retarder rotor speed, and the output shaft, to decrease and slow the vehicle.



When the retarder is deactivated, the retarder cavity is evacuated.



Additional retarder information can be obtained by ordering our free Motor Home video, "Operating the Allison MH Series Transmission" (VI3424EN). Click on this link for ordering details.



Motor Home Video


:)

[rfoster]

That is not a misprint, I meant retarded. I too have the retarder and I can not go anywhere unless I am up and down the hillls because of the area I live in. I have to use it constantly. I believe it was designed for flat areas. Not only can you cook the tranny oil, the tranny then will shift very hard and feels like it will jerk something loose until it has gone thru enough shifts to wash the retarder from its memory.

If I was in the process of evaluating a new to me coach purchase the retarded would not prevent me from purchasing it, but would definitely get a check on or in the minus column.

We have had similar discussions on one these forums before about this, and we have yet to come across anyone who truly understands the benefits of the retarded over the jake.

I am in agreement with Jon and Toms remarks.:cool:

[Gary & Peggy Stevens]

That is why I am glad I joined this group, especially before I purchased a bus. The information you guys spew ( a good thing ) forth is just fantastic.

I learn so much from reading all of your posts, I just can't stand it.

Thanks again for all of the invaluable information. :)

Any of you going to be at the Tampa RV Show? Are you in your bus, or staying at a Hotel. :confused:

Peg and I are flying in Friday night the 19th, and staying at the Red Roof Inn, which I believe is next to the fairgrounds, and checking out all the bus's, Saturday and Sunday.

Call if you are in the neighboorhood. 713-252-2599 :D

[Jon Wehrenberg]

Gary,

I'll take a 180 turn here.

If you find a coach you like don't make the decision to walk away from it because of the retarder.

You see how most of us feel, but it does not have to be a show stopper. First of all a retarder works. It assists in braking and it will help control speed going down hill. A Jake allows the driver to be less attentive, but to make a retarder work effectively and not overheat you as the driver has to plan ahead and that is not a bad thing. I get the best compromise by leaving it in the second position and slowing down slightly just before the steep downhill. That keeps the bus going downhill at a reasonable speed and it keeps the temperatures very low.

With a Jake you can be going fairly fast, and put it in the high setting and downshift and it will do a great job and you don't have to worry about it, but these buses are more than just retarders.

[Jon Wehrenberg]

Information on the Allison Transmission and retarder can be found here by opening the PDF file.

http://www.allisontransmission.com/publications/pubs/OM3349EN.jsp

Here are some highlights that may prove of interest. With a retarder service intervals are cut in half. If you use Dextron you need to change fluids every year or 12,000 miles instead of 25,000. Transynd is impacted similarly, but has longer oil change intervals, depending on some other factors such as flilter types.

The retarder force will be reduced if the fluid overheats. I mispoke earlier. It appears that the computer will eliminate the need to worry about temperatures.

Speaking of temperatures: they vary depending on where the temperature reading is taken. The sump oil temperature maximum is 250 degrees F. More details are available at the link above.

Instead of having to take the bus to Allison to deal with harsh shifting, it appears by using the correct inputs we can clear it so the transmission can reprogram (self teach) itself.

The file is 94 pages with lots of good information.

[Toy Box]

Same experience here. Last two buses had jake brakes... two cycle detroit 8-92 engines. Current bus has retarder... four cycle detroit. I think the jake was idiot proof as far as operation. The retarder took a few trips over the Rockies before I was comfortable with it's operation. Today, I really don't have a preference.

[garyde]

On my way out to Santa Fe, it was brought to my attention that I was riding my brakes and black smoke kept poping from my exhaust. Well, it was the Trans. retarder. I had left it on and any time I let my foot of the gas, it would slow the Coach down and then I would apply the gas. So, you have to be more aware of what you are doing. I was told you could raise the temp up to 290 degrees no problem. But I can not remember who at POG II told me. It is great for slowing down coming off the freeway, or having to make a rapid deceleration. I have to watch it on long down hill slopes.
My Country Coach Lexa has a 3 stage Jake and I liked that a lot also.

Finally, I really like my Liberty . Gary

[Gary & Peggy Stevens]

RVbus01 The link did not come through for the Allison Tranny video, please send it to me again. From your information you apparently know your transmission, wow, great description of retarder action.

Gary

[Jon Wehrenberg]

That entire text on the retarder plus a whole lot more is on the link on my previous post. I learned a lot when I read it because it gives some good indepth information.

[jonnie]

While at DDA recently I was informed that the transmission temperature using the retarder can go as high as 280F to 290F but not for extended periods of time.

John

[timebum]

I have owned both systems and favor the retarder. It gives you much more control over braking and temps are not an issue that people make them to be. Running Transynd solves the temp question and the noise that the Jake makes shake small town tempers.

[Jon Wehrenberg]

If they can number the Superbowl in Roman numerals surely we can handle them.

There is something classy about triple XXX.

[Petervs]

A quick review:

The bus is moving at some speed and you want to slow down. There are 3 common ways to do this:

A. The service brakes convert the kinetic energy to heat into the brake hardware by friction of the pads or shoes against the discs or drums.

B. A Jake brake uses the kinetic energy to compress air, which is then "wasted" out the exhaust system. No heat is generated.

C. A transmission retarder converts the kinetic energy to heat inside the transmission. The heat must then be removed by the transmission oil cooler. The cooler is a small "radiator" mounted in front of the big radiator and the transmission fluid needs to pass through here a time or two to cool off the transmission, which will take a few minutes or more depending on the outside temperatures and heat load on the transmission.

All three methods do slow down the bus. Method A and C will eventually reach the point where the heat added by slowing is greater than the heat dissipated by airflow. For a single stop in traffic all will work well. For lots of stops in traffic all will work well for a while, but eventually A and C will begin to reach their limits. For descending a long grade eventually A and C will overheat. B will just keep on working, leaving the service brakes fresh and cool.

For these reasons I prefer the Jake Brake. Especially if you live and travel mostly in the western states, almost anywhere you go you encounter mountain roads and passes. Knowing the Jake is ready to manage downhill speeds without needing the service brakes at all times is very comforting. You can select most any downhill speed by choosing the gear and setting the Jake on high or low. It is easy, effective, and the system has been trouble free.

Then there is the issue of some towns and their signs about compression brakes. I have noticed the wording of these signs varies from place to place. Some I have seen say "Unmuffled Compression Brakes Prohibited" , or " Jake Brakes Unlawful in city limits", "Use of Engine Brakes Prohibited" or some such.

I take the approach that in any kind of emergency, I will use all the braking systems I have no matter the signs in the area. Also, since the Prevost installation IS a muffled engine brake, it is not nearly so loud as what we typically heard on logging trucks, etc in the 1970's when the Jake Brakes came into common use and many of these signs sprang up. I have never heard of anyone getting stopped or ticketed for using the Jake Brake, but I would like to know if it has happened. Anyone?

Another interesting point, on my 94 the brake taillights come on when the jake brake is working, and when you step on the service brake pedal, the red light on the dash also comes on to indicate that. So, someone behind you might think you are riding the brakes all the way down a long hill when actually you might not have touched them at all. And if you are decelerating into a town that has several speed reductions as you come to the center, while the Jake is working any local policeman will see that you are slowing down and not ignoring his speed limit on purpose. SO far I have never been stopped for that either, and wear and tear on service brakes can be minimized.

One further note, I have driven both a Series 60 Detroit bus ( mine) and a 8V92 Detroit bus. The Jake effectiveness was noticably more in the Series 60 version when the setting on both was on High.

As always, comments welcome!

Peter vS
94 Marathon XLV

[rfoster]

IMHO The transyn may have helped the temps some, but not enough for the difference in the price. The temps have concerned me enough that I am on my second dose. I don't know that I will use it again although I have had one so called mechanic tell me - once you use it, you must stay with it. I have been BSed before. Any body else heard that?

[truk4u]

Peter,

Marathon must have changed the jake/brake light in the later years. Mine does not operate the brake light and works with cruise control as well. ;)

[jello_jeep]

Tom, my brakes lights come on with the jakes, at least the light on the trailer brake controller comes on, so I assume the brake lights are on!

[Petervs]

Peter,

Marathon must have changed the jake/brake light in the later years. Mine does not operate the brake light and works with cruise control as well. ;)

Thanks for the further info. My bus has the DDEC II system, and it is not sophisticated enough to allow user programming of the Jake Brake with cruise control, but the later DDEC III and IV are. You just hook up the reader box and set on or off with cruise control as you prefer.

That points out the one deficiency I see with my set up, while toolig down the interstate and you start descending a little, well, the bus just picks up speed like a ball bearing rolling down a ski jump and before you know it you are doing 85. So, you have to stay alert and kill the cruise on a big downhill. That can be a pain if you are in a place like Interstate 5 in southern Oregon where there are a long series of 10 miles up hill followed by 10 miles downhill. But, clearly, Prevost addressed that on the later busses. Not enough reason to convince me to trade up though.

[Gary & Peggy Stevens]

Thanks again guys for all the important information about Jakes and Retarders. I can honestly say I am only half as confused as I was half a week ago. (just kidding)

Thanks for the info.

Gary

[Stelan73]

A quick review:

The bus is moving at some speed and you want to slow down. There are 3 common ways to do this:

A. The service brakes convert the kinetic energy to heat into the brake hardware by friction of the pads or shoes against the discs or drums.

B. A Jake brake uses the kinetic energy to compress air, which is then "wasted" out the exhaust system. No heat is generated.

C. A transmission retarder converts the kinetic energy to heat inside the transmission. The heat must then be removed by the transmission oil cooler. The cooler is a small "radiator" mounted in front of the big radiator and the transmission fluid needs to pass through here a time or two to cool off the transmission, which will take a few minutes or more depending on the outside temperatures and heat load on the transmission.

All three methods do slow down the bus. Method A and C will eventually reach the point where the heat added by slowing is greater than the heat dissipated by airflow. For a single stop in traffic all will work well. For lots of stops in traffic all will work well for a while, but eventually A and C will begin to reach their limits. For descending a long grade eventually A and C will overheat. B will just keep on working, leaving the service brakes fresh and cool.

For these reasons I prefer the Jake Brake. Especially if you live and travel mostly in the western states, almost anywhere you go you encounter mountain roads and passes. Knowing the Jake is ready to manage downhill speeds without needing the service brakes at all times is very comforting. You can select most any downhill speed by choosing the gear and setting the Jake on high or low. It is easy, effective, and the system has been trouble free.

Then there is the issue of some towns and their signs about compression brakes. I have noticed the wording of these signs varies from place to place. Some I have seen say "Unmuffled Compression Brakes Prohibited" , or " Jake Brakes Unlawful in city limits", "Use of Engine Brakes Prohibited" or some such.

I take the approach that in any kind of emergency, I will use all the braking systems I have no matter the signs in the area. Also, since the Prevost installation IS a muffled engine brake, it is not nearly so loud as what we typically heard on logging trucks, etc in the 1970's when the Jake Brakes came into common use and many of these signs sprang up. I have never heard of anyone getting stopped or ticketed for using the Jake Brake, but I would like to know if it has happened. Anyone?

Another interesting point, on my 94 the brake taillights come on when the jake brake is working, and when you step on the service brake pedal, the red light on the dash also comes on to indicate that. So, someone behind you might think you are riding the brakes all the way down a long hill when actually you might not have touched them at all. And if you are decelerating into a town that has several speed reductions as you come to the center, while the Jake is working any local policeman will see that you are slowing down and not ignoring his speed limit on purpose. SO far I have never been stopped for that either, and wear and tear on service brakes can be minimized.

One further note, I have driven both a Series 60 Detroit bus ( mine) and a 8V92 Detroit bus. The Jake effectiveness was noticably more in the Series 60 version when the setting on both was on High.

As always, comments welcome!

Peter vS
94 Marathon XLV


Peter: Most of the posts I have read are pro jake. If the jake system is preferred by most, why did Prevost go the retarder route on new shells?

[Petervs]

Peter: Most of the posts I have read are pro jake. If the jake system is preferred by most, why did Prevost go the retarder route on new shells?

According to the Prevost website, both the Jake brake and the retarder are options on their shells. You can get them either way. I suspect the Jake brake costs more as a factory option.

http://www.prevostcar.com/cgi-bin/pages.cgi?page=xl2c_chara&tab=powertrain

I personally also prefer the Jake brake. Might be nice to have both! The only downside would be cost.

Peter vS
94 Marathon XLV

[Jon Wehrenberg]

I too question why a retarder would be used in place of a Jake.

It is abundantly clear by the maintenance schedule that Allison considers a retarder equipped transmission so hard on the fluids that change intervals are cut in half.

There is a real plus for the Jake. When our granson was little when he travelled with us and we went through tunnels he loved hearing the sound of the Jake. He thought that was great.

[dreadnought]

See my earlier post. The retarder costs more, much more.
And Peter, The Jake on my Peterbilt is hooked to the cruise. If it can't hold the set cruise speed on a down grade the 1st stage comes on, if that doesn't do the trick the second stage and then the 3rd if needed. All automatically, with no driver input. Towns put up no Jake signs cause Grandma got tired of being blasted out of the bed at 2 AM by "chicken trucks" with straight pipes. My truck has 8" pipes with no mufflers but I've never had a problem cause I know when to behave. :cool: Jacobs Engine Brakes have been around for billyuns and billyuns of miles and work, period. I'm telling you, this is all a plot cooked up by Allison to sell trannys.

[Petervs]

See my earlier post. The retarder costs more, much more.
And Peter, The Jake on my Peterbilt is hooked to the cruise. If it can't hold the set cruise speed on a down grade the 1st stage comes on, if that doesn't do the trick the second stage and then the 3rd if needed. All automatically, with no driver input. Towns put up no Jake signs cause Grandma got tired of being blasted out of the bed at 2 AM by "chicken trucks" with straight pipes. My truck has 8" pipes with no mufflers but I've never had a problem cause I know when to behave. :cool: Jacobs Engine Brakes have been around for billyuns and billyuns of miles and work, period. I'm telling you, this is all a plot cooked up by Allison to sell trannys.

Sure, I agree, but I bet your Peterbuilt is newer than my 1994 with a DDEC II. The later ones do it your way and that would be a great feature to have. But like I said, I do not think I will change coaches for just that.

Peter VS

[Jon Wehrenberg]

It seems clear we would like to have a Jake instead of a retarder, but there is a downside to the Jake that nobody has mentioned yet. A Jake works best at higher RPM.

One thing I have noticed with the retarder is that when it is on and I hit the brakes the retarder aids in stopping power to a noticeable degree. With the Jake, when we got down below about 20 it dropped out and while it wasn't like the coach accelerated, there was a noticeable loss of stopping assistance.

I guess if it could be done Perter's idea of having both would be the ideal.

[Just Plain Jeff]

I really don't know what I am talking about (as usual) so bear that in mind.

However, our Angola had a retarder which was almost useless. That bus just did NOT want to stop. Witness the knuckle-marks on the steering column and my footprint on the brake pedal!

The Vogue had a Jake Brake on it and it sounded kinda cool (now we are Series 60 land), but I didn't see any big difference in stopping power with it.

Our new camper has kind of a neat deal. On the right hand side of the steering column there is a lever with a 4-position adjustable retarder. I was goofing around with it the last few days and as the tranny downshifts and you change the range of effect on the retarder, you slow down mighty quick.

I wasn't looking at the temperatures as I try to watch the road, mostly.

So that's my 2 cents worth.

[Jon Wehrenberg]

This may be a rather difficult concept for a postal worker to grasp, but since he is alone and presumably desirous of avoiding trouble, and with the lady of the house tending to the welfare of New England, maybe he might want to spend spare time with a good book, like the owner's manual.


That unknown device to the right of the steering column is not the RH turn signal switch, but a supplement to your braking power. Since you may be driving that rig in close proximity to mine, please read what neat things like that thing does. It just may keep you from bumping into me.

[Just Plain Jeff]

Jon:

Thanks for the good idea.

However, I don't see very well, so the manual is a problem.

I use the 'Audio Parking Method.'

When you hear it crash, step on the brake. That's the one left of the GO pedal, right?

[Jon Wehrenberg]

Whoa......That's all I say and it stops. Whoops, that is one of Deb ponies. I don't know how to stop the bus. I haven't gotten that far in training.

[Orren Zook]

They told me that was why there are those little rubber bumpers on the Prevost Car Chassis now, for supplimental braking while operating or parking close to other vehicles.

[garyde]

I am still on the fence with my Trans. Retarder. I was not using it correctly to begin with, and then when i knew more about it and the Heat issue , I became more frugel.
Troy at Liberty said I would really enjoy having the Retarder, and I can say it works great on off Ramps, Stop Signs, and Stop and Go Traffic, and emergency stops.
On down grades, I brake to about 55 or 50 MPH and then apply the Trans Retarder to the 1st or 2nd position. I then cruise until the speed exceeds 60 to 62 MPH , then I brake again and start the process over agan.
I leave it off most of the time except on grades.
The temperature climbs to 290 on long downhill grades.

[Jon Wehrenberg]

Gary,

When we first got ours I was reluctant to really engage it because I could see the transmission temperature gauge racing upward.

But....I think I have a good compromise the way I use it now. First I leave the switch on, but do not put the lever in any of the "on" positions. What this does for me is it brings the retarder into play if I have to do any braking.

When I encounter hills and want the retarder to help hold me back I put the lever in the second position. That seems close to the help I got from the Jake on our first coach, and unless I get on the brakes temperatures range up to about 210 to 220. If the hills require braking, I just watch the gauge and try to limit it to 230. That is just my limit because I know high oil temps are hard on the transmission and the oil. Allison proves this with their reduced oil change intervals when a retarder is used.

BTW, I do not wait until I need the retarder. In hilly country I leave it in the second position as soon as I see I will need it and it manages temps nicely. It also downshifts by itself to make the retarder more effective.

The only thing besides temps I dislike is the brakes lights come on and that must drive anyone following me nuts.

[Gary & Peggy Stevens]

Gary,

The only thing besides temps I dislike is the brakes lights come on and that must drive anyone following me nuts.

The brake lights coming on when the retarder slows the bus down, seems like the proper thing to do, I mean the guys behind you got to know your slowing that animal down?

You wouldn't want anybody running up behind you and kissing your rear end, cause they didn't know you were slowing down.:D

Thanks Jon, and everyone else for the information on the Retarder, and Jake brake.

I can honestly say now, when we find the right bus, it won't sway me one way or the other if it has the Retarder or not, but I still kind of like the Retarder idea over the Jake. :cool:

[Jon Wehrenberg]

Gary S.

The brake lights are annoying at night to those following. With the retarder on simply lifting your foot from the accelerator with the retarder on lights the lights, and even with them on you may actually be accelerating down the hill.

Day or night with them constantly coming on when the retarder is engaging (cruise control on or off) eventually a vehicle following treats them as meaningless and when you really have to get on the brakes what will alert those drivers other than the brake lights that have previously been meaningless?

[Gary & Peggy Stevens]

Thanks Jon, now I understand.

[BrianE]

I agree with Jon about the brake lights coming on. The Jake in our busses (8V's are the worst :( ) are not nearly as effective as they are in a truck and no truck that I've ever driven has jake actuated brake lights. I admit I don't have the trucking experience of many of our esteemed Poggers so I might stand to be corrected. Tom? Joe?

Last year Beverly was descending a long grade in the bus, we were being followed by an acquaintance (Winnebago). At the end of the day I was approached confidentially and told I might need to counsel my wife about riding the brakes. Needless to say I set him straight very quickly and ever since have been meaning to try and disable this feature.

This discussion prompted me to call Prevost yesterday morning. I was informed by one of the area service managers that this is a common request and he promptly informed me that removing Relay 76 labled "Jake Brake Signal" in the engine compartment electrical panel would disable this feature. I can't imagine he would have shared this information with me if Prevost feels this is a significant safety item. Needless to say, I now have another spare relay. Of course it's very possible that different models and years may have varying relay numbers but would bet the labeling would be correct.

BrianE
94Liberty XL

[truk4u]

Brian,

The older trucks did not turn on the brake lights with the jake, the newer ones do. My Marathon does not turn on the lights and I wouldn't have it any other way. I like the jake function while on cruise control. My chassis is 10 years old and if the brake lights came on with the jake, I would lose the cruise. I suppose the newer buses have become more electronic where the jake/cruise/light are all controlled by the computer and work in harmony.

[Gary & Peggy Stevens]

During the Tampa RV show I stopped at the Allison Transmission booth, and asked the Allison Transmission Man, the question I posed to you guys earlier in this Post.

Retarder or Jake Brake.

This information comes straight out of the Allison manual and agrees with pretty much everything everyone out there has said, but I thought I would pass on the information as it is 100% Reliable. :)

The cost of owning and using a Transmission Retarder DOUBLES compared to the ownership of a Jake brake. But I guess you all knew that :rolleyes:

Fluid change using Transynd is 300,000 miles Normal Operation or 48 Months
Fluid change using TES389 is 150,000 miles using a Retarder or 48 Months
Fluid change using Transynd is 25,000 miles Normal Operation or 12 Months
Fluid change using TES389 is 12,000 miles using a Retarder or 6 Months.

The filter change is also dramatically different ( Cut in Half ) depending on Retarder or NOT.

The problems of overheating, and causing major problems apparently has been solved or eliminated, because the Allison Man said they had experienced no problems recently??? Even Rick Thompson insists on the Retarders and believes in them, and puts Retarders on all of his new Thompson coaches.

Enquiring Minds want to KNOW

Gary S

[Jon Wehrenberg]

Gary: You may wish to edit the maintenance schedule to reflect Dextron, not transynd requires 25000 mile changes and Dextron will never go 150000 miles with a retarder.

[JIM CHALOUPKA]

Gary, Please check your post for typos and weather you said what you meant. If everything is correct I will be back for an explanation. :D:D JIM

[Jon Wehrenberg]

I think Gary just transposed fluids in his tabulation.

But re-reading the post brings something to mind that the pilots on this forum will appreciate. We are guided by limits. We have limits for airspeeds, oil temperature, cylinder head temperatures, etc.

These limits are exactly akin to the Allison transmission limits for temperature.

There is not a pilot on this forum, or any other for that matter that runs his plane at the limits unless he is attempting some speed or other records. If our transmission temperature limit is XXX, the further we are from that limit during normal operations the better it is for the life of the fluids and transmission. They are saying that without saying that explicitly by classifying the use of a retarder as severe duty.

I agree the transmission retarder might be more effective than a Jake, but I want my Jake because every time my retarder kicks in I know I am taking money from my pocket and I am having an adverse impact on my fluids and transmission.

[rfoster]

The comments from the Allison Tranny Man reminds me of the comments of one my former employees: " I ain't lying this time".

[Gary & Peggy Stevens]

Gary: You may wish to edit the maintenance schedule to reflect Dextron, not transynd requires 25000 mile changes and Dextron will never go 150000 miles with a retarder.

I tried to copy the Schedule Maintenance Log out of the Allison Info packet but could not find a way to copy it into this Post. I will try to correct any misinformation I gave last night.

Two types of Filters Gold Series / High Capacities

The information I posted yesterday was taken from the High Capacity Filter Information not the Gold Series, which I am sorry was very misleading.

Jon, you mentioned Dextron, but Transynd or TES295 is mentioned all over the information packet as the Fluid used ? The Optional fluid and changed more often fluid is TES389 or MIXTURE* as stated in the booklet?

The mileage (300K) I posted was taken directly out of the information provided for the 4000 series High Capacity Filter info.

But after I got your reply posts, I got on the web like I should have gotten the first time and found this VERY INFORMATIVE AND HELPFUL WEB SITE. This should help clear everything in my post up, and correct any and all MisSpeaks that I may have entered last night.
http://www.allisontransmission.com/service/changeinterval/index.jsp

Sorry I was trying to be helpful, but just confused the issue. :o My MAIN reason for posting was to Strengthen the advantage of the Jake vs the Retarder due to the Higher Maintenance cost.

[Jon Wehrenberg]

Gary, quite the contrary. You did not confuse anything because of inadvertandly transposing a listing. We know what it meant and thanks for posting.

I am using the common terms of Transynd which is a proprietary synthetic (Castrol I think) and Dextron, the common ATF.

[JIM CHALOUPKA]

Gary, Have no fear the typos are inconsequential. Since we are trying to be exrtemely accurate I just wanted to mention it in a friendly way. You know 300,000 mi. from now I might forget what I now know. When I go to look it up I just want the data to be right. Thanks for going the extra mile to be helpful. :)JIM

[MangoMike]

Having just recently experienced with a lot of miles both the Jake (H3)and The Retarder (Libery Xl1) (or The Retardo as the Mangoettes call it). I have to comment.

Retarder Hands Down Winner:

Performs as intended in slowing the bus down. Does a much better job than the Jake. I can come off the interstate into the decelaration lane and use the Retarder without having to touch the brakes until it drops into first gear. I can't do that with jake. With the Jake I'm using the brakes a lot more than with the Retardo in the Liberty.

I know all the worries and comments about fluid temperature, and until a month ago when Jon posted here I thought the magic number was 230, but even out West, with some planning, I rarely exceeded 230. Now I know this means more frequent fluid changes, but I think this is a small price to pay. The bus definetly stops quicker and with less brake action with the Retarder.

I wish is was on the new H3.


Mike

[truk4u]

Mango Man,

Are you sure your in the high position with the Jake? Turbo boost will tell the story when comparing the low/high setting.;) Your also probably heavier than the poor ole long forgotten Mothership I.:D

[MangoMike]

Trukman,

Definetly in the high position. You're right, weight be a factor, but there is a dramatic difference.

Mike

[Jon Wehrenberg]

Strictly an opinion here, but a Jake is sensitive to high RPM. It wants high RPM to be effective and with the Series 60 which in our buses is biased to let the economy mode be primary it is possible the Jake is working at much less than its full potential.

As to the suggestion the retarder output temps are not exceeding 230, I believe that but also know when the retarder is on and brakes are applied the temps exceed that. The cynic in me suggests that is why the newer coaches with retarders do not have a transmission temperature gauge. That information is available, but the driver has to scroll down through pages in the ProDriver to access the information and in this marketplace few drivers even think about these things.

[Gary & Peggy Stevens]

Hey Mike, I think you can have a Retarder added to your new H baby, if you really wanted to? Somebody feel free to correct me if I am wrong about this.

I tried to find some info on the Allison Transmission web site, to send along but could not find anything about the retarders at all?

Gary S

[jonnie]

If you don't believe your jake is slowing you down as it should and if it is RPM sensitive as Jon says, I believe Allisson can adjust the Jake and the trasmission to go from 6 to 2 instead of 6 to 4. This is how my exhaust brakes worked in the past, but I don't if this applies to Jake Brakes.

John

[Jon Wehrenberg]

John,

The Jake is independent of the tranmission and is integral with the engine. It functions by dumping compressed air from the cylinders when the coach is coasting. It has a high and low position which uses more or less cylinders.

A retarder is integral to the transmission, and when in use it will downshift as programmed. When using a Jake the driver must manually downshift.

[rfoster]

Mango: FYI, Frank K., Jr. at Liberty was asked by A1 - why the retardo? vs the Jake? Response was - it stops better. End of discussion.

In addition the new lower sulphur fuel at 15 ppm has less BTUs, requiring more fuel to achieve the same power meaning that Al Gore has come up with a plan to burn more fuel to burn less sulfur? It is pretty well a given that the fuel economy of the series 60 will be negatively impacted by two tenths to .25 mpg with the new fuel. This according the Detroit Diesel representatives at the recent Liberty Rally.

Dang its cold - I liked the good old days before global warming, I hope it warms up soon.:cool: .

[Jon Wehrenberg]

Fast Roger is an optimist.

Since I record every single gallon of fuel that flows through my bus I will be able to compare the last 12 months fuel burn per mile with the previous 12 month period and I will share the results at POG III.

I can't go further back because we got the Hummer 24 months ago and the Jeep was lighter.

I drive at the same speed so the results will show the real impact of the fuel change. It is probably double what DD says.

[MangoMike]

Hey Mike, I think you can have a Retarder added to your new H baby, if you really wanted to? Somebody feel free to correct me if I am wrong about this.

Gary S

Gary,

Not at a good use of Lew Bucks at this time. I'll just learn to live with it and stop whinning.

Thanks

Mike

[Joe Cannarozzi]

I have a question about our trans, kinda unrelated but.

Our trans selector has 5 marked forward gears yet I can feel, without a doubt, 5 distinct shifts giving it 6 forward speeds. Would someone care to shed a little light.

Also while at TGO talking with Bill he mentioned that he cruises at 50something and I asked him if that speed kept him from high gear because our bus won't even shift into final gear till 60 minimum. His responce was no, it is in final gear at 50something?

One more note for anyone trying to answer. There is a wide range from 1st to 2nd and 5th to 6th but 3rd and 4th have short close ratios. Also the build sheet shows the rear end has a 3.32 ratio, or is it 3.23.

Its an older bus and really can't say if its the original trans or not. Are there defining visual charicteristics between the 2?

[Jon Wehrenberg]

The first "shift" you feel in your tranmission is actually the torque converter lock-up.

[Joe Cannarozzi]

That would explain the firmness of it as well, downshifting too. Thank you Jon.

[Ray Davis]

The first "shift" you feel in your tranmission is actually the torque converter lock-up.


Thanks for explaining that. I've had exactly the same "feeling" on mine, i.e. one more shift than expected gears!

[jonnie]

Regarding the shifts of the transmissions, and Jon is probably more up to speed than I am, I believe there are several gears where you go from converter to lockup. On the 6 speed the final 2 gears are really overdrives and I believe you are in lockup.

Jon, I also stopped at DDA today because I was curious about the manual down shifting when using the Jake Brake. The tech told me this can happen either manually or elctronically. In my case since I go from 6 to 4 immediately and automatically, it can be reprogrammed to go down thru the gears automatically and end at 2.

John

[Jon Wehrenberg]

I know the retarder downshifts can be programmed with the normal downshift from 6th on the World transmission being to 4th.

I think if the Jake activation triggers a downshift it must be on newer coaches with the 6 speed transmission because on my 5 speed transmission (which had DDEC and ATEC) all downshifts were manual.

[Gary & Peggy Stevens]

Gentelmen, I am back on for more information about my Jake Brake.

As I posted when I got my bus, back in March 08, I don't think my Jake Brake is SET properly? Can the Jake brake capability be adjusted somehow? I would like to have more braking power coming from the Jake when I release the accelerator.

Someone told me it should downshift the transmission, automatically if it is set up correctly, is this true? It seems to me, it has no way to do anything with the tranny.

I was told it could be adjusted or checked for proper adjustment? Anybody know if this is true, and which one of the many mfgs. is responsible for this.

Can it be looked at and adjusted by Prevost while in their shop?

Thanks

Gary S.

[jack14r]

I think that a Detroit Diesel and Allison shop can help you with the Jake and downshifting which it should do.Back to the earlier post in this thread,I have a retarder and my new coach has a huge trans.cooler and I haven't seen the fluid temps.rise more than 8 degrees even in the mountains of NC,VA,KY(not real mountains)Black mountain on I 40 in NC is the greatest grade that I have descended with this bus and the temps are very steady all the way down.

[Larry W]

My coach does not downshift when the jake comes on. I would not want it to downshift as I rarely turn the jake off. The jake works best with high engine RPM. As a rule I downshift at about 1400 rpm when slowing down for traffic lights, freeway exits and such. This requires less braking plus saving the brakes for a need to stop in a hurry when the XXXX pulls out in front of you.

[Kevin Erion]

I agree with Larry, I also know that they can be checked for adjustment and if they are out, when put back to proper specs will work better.

[truk4u]

You want the downshift, that's where your going to get the most bang for the buck by high rpm's. If you have one that doesn't downshift to 4th gear (depending on speed) someone has had the program changed.

[Jon Wehrenberg]

Truk,

I'm not so sure. My Jake on the first coach required a manual downshift and in retrospect I prefer that. At highway speeds my RPM would be more than adquate for most downhill driving. If I knew the grade was steep I then had the option of slowing down a little and dropping to a lower gear.

The retarder on the current coach automatically downshifts so I find myself leaving the switch on so I have retarder when braking, but I manually pull the little lever into the #1 or #2 position if I want the retarder to come on when coasting, like going downhill or approaching an exit. Otherwise I leave it off.

What I don't like about it downshifting automatically is if I am on cruise control, every time the cruise closes the throttle the brain thinks the retarder needs to come on so it downshifts, and then when the highway levels or goes up a little the transmission hangs in the lower gear for longer than I want it to. Up, down, up, down. It's like it is hunting.

My jake would not operate with the cruise on on the old coach.

[Gary & Peggy Stevens]

Thanks guys for the replys. From what I am hearing I believe that my jake braking operation was changed. It works with the cruise on, which I want, and I can feel it work but only a little currently so I will have someone get in and check the set up of this system and evaluate.

To have it serviced at DD or Alison what exactly are they servicing? The DDEC IV computer or something else. In other words is it a computer controlled issue or mechanincal adjustment?

Thanks Again.

Gary S.

[Steve Bennett]

Gary, an Allison dealer can set & verify the transmission parameters via a lap top. You can have the transmission programed to try to down shift to a specific gear when the throttle is released & the Jake is on. Typically, you will see them set to try to get to 4TH gear. There are also solenoids in the valve train of the engine that can fail, or not fully engage. These can be checked by a Detroit shop.

[Ray Davis]

When I was in FL picking up my bus, the technician mentioned that you can have the jake brake setup for "aggressive" mode. I don't know if this is fact or not, but I wouldn't be surprised, since as Steve indicated they are programmable.

My new coach, and as I remember none of my previous coaches automatically downshifted. I have to manually downshift in areas where I want more braking.

Ray

[Will Garner]

Awhile back I was stopped at a traffic signal. Yes it was red and had been for many seconds. Just before the signal turned green, I feel a thump on the rear bumper of my 1996 Lincoln Town Car. Now this is the third time I have been rear ended. I did not know my rear end was so very attractive!

Anyway, I get out and approach the offending vehicle. It is being driven by a little old lady, not from Pasadena, but a retiree from Whispering Pines. She causually rolled down her window and proceeded to say, " But I was slowing down." I could not help myself. I told her that was fine but my rear bumper was NOT part of her vehicle's braking system.

Life goes on.

Later ...

[grross]

After having had a transmission retarder on our previous coaches that worked flawlessly, I was not to happy when my wife picked our current coach which has a 2 stage engine brake. After being told by Prevost I could have a transmission retarder added for approx. $ 20k, I decided to proceed, the price tripled; then they concluded it couldn't be done because of cooling consideration. My son suggested I go to Penn Detroit Diesel in Ocala. I bet the tech a lunch he could not improve the stopping characteristics to match a transmission retarder. Happily I lost the bet!! It took 18 minutes after he hooked up his laptop...he let me modify the transmission profile. He explained to me that they reprofile many entertainer & converter coaches from activate on 6th gear only to as many gears the driver prefers. When I took the coach back to Marathon (FL). The techs (several of whom had brought the coach to NC) drove the coach and were amazed at the difference in how the coach stopped.

[dale farley]

Reposted for revelancy.