Trip Coburg Or.To San Antonio Fl.

[Jon Wehrenberg]

Allison has a fliud change schedule. For example, the factors which affect the service intervals are whether you have a retarder, transynd or dextron, or the type and size of transmission filter.

A coach without a retarder, using other than transynd, and having a 2" gold seal (not high capacity) filter should have its fluid and filters changed every year or 25,000 miles whichever comes first.

That jumps to 150,000 mile fluid changes, 75,000 mile filter changes (high capacity filter) or 48 months, whichever comes first if the coach has a retarder, or 300,000 if it has no retarder.

http://www.allisontransmission.com/s...voc=MH&type=4k

You can use the above site to determine your service intervals.

The retarder is clearly considered to be subjecting the transmission fluids to harsh duty.

[Jon Wehrenberg]

This is another good link to save:

http://www.allisontransmission.com/s...t=OM3349EN.pdf

[Ray Davis]

Thank you very much. I had planned on waiting till after Pahrump for a full service. I'm thinking sooner than later, now.

Ray

[CAPT MOGUL & Sandy]

My vote is in favor of the Jake. Descending a steep grade the retarder would have the greatest effect, but then looking at the temp gauge going off the scale, the retarder becomes ineffective as the oil goes beyond the boiling point. Now you are on the brakes to keep the temp down. Over several years I noticed low mile coaches that were advertised with rebuilt transmissions. The only thing that caught my attention was that they all were equipped with retarders. I know you all with retarders wont want to hear this but a Jake is a set and forget it, and with the retarder you must monitor the trans oil temp or face future maintenance problems. IMHO Sorry
Ed

[Jon Wehrenberg]

I stated before that I prefer the Jake, but in defense of the retarder there are some very important benefits.

First, I use the second position and when descending even fairly steep grades it manages the speed very well, and the temperature usually stabilizes at around 220. If the grade is excessively steep however, using the brakes in addition to the retarder will drive the temps up, so I end up turning off the retarder, using the brakes to get below my target speed, and then reengage the retarder. That limits temps but wears out some brake pads.

But the good point is that by leaving it on all the time, if I have to make a hard stop, the retarder is proportional to the brake. The harder I press the brake, the more assist I get from the retarder and that is a considerable benefit.

Ed's comments about premature failure are unlikley related to the retarder. Allison had some issues with clutch material in the earlier world transmissions and the clutches wore to such an extent the transmission filters and pan would actually get loaded with that material. The newer versions of the world transmission allegedly have addressed this problem. The clutches are serviceable, but the cost of a factory rebuild is so close to a field rebuild it just makes sense to replace the tranny.

[garyde]

Gary. On my previous Country Coach Lexa w/ the 3 stage Jake Brake, if the cruise control switch was in the on position, the Jake Brake would not work.
Jon. i guess what I am saying is I never have allowed my Trans temp to exceed 228. I usually reduce speed to 55 mph at the top of a grade and maintain this speed thru using the retarder and intermitant braking. I have the transynd oil.

[CAPT MOGUL & Sandy]

I believe my point was,that some drivers were not aware of the consequences of over heating the trans oil with the retarder. Allison was aware that the recommended C-2 oil was not handling the heat these transmissions were generating in "normal" operating conditions. This is why the "Transend" development, better lubrication at higher temperature limits. Ed