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Jim_Scoggins
04-28-2008, 04:24 PM
Just for info:
This last weekend I took the first step in converting to a synthetic lube (Transynd) in the transmission. I just wanted you all to know the benchmarks I saw in refilling the tranny. It appears I have the 2 inch pan and I presume most Prevosts have the same. It matters pertaining to which filters one uses.
I dumped the fluid from the pan using the drain plug and I loosened the 12 bolts on the two filters so fluid would drain out of the those cavities. I did not drain the lines going to the trannny oil cooler. I got about 6.5 gallons out by letting the stuff drain for about 1.5 days.
I put in 5 gallons: There was no evidence of fluid on the dip stick.
Added a gallon for a total of 6 gal: Evidence of fluid on the bottom of the dip.
Added another gallon for a total of 7: Fluid was at the high cold mark.
Ran the coach for a bit until the oil temp was over 160: Fluid level was just shy of the low hot mark.
I added another half gallon. Will take the coach out next weekend and get it all the way up to operating temperature and check again.
Why didn't I change the filters? They were new last August.
My plan:
In about a year I will dump the fluid again, and change the filters. That should get rid of most of the old fluid. There after I will do the filters (a filter change will drop about 2 gallons) for a couple of years, then leave it alone.

Jim_Scoggins
05-20-2008, 06:21 AM
Just for info and close the loop

Ran the coach for about 80 miles last weekend. Added a touch more Transynd to bring it almost to the "hot full" mark.

Total of 8 gallons of Transynd back in.

Jon Wehrenberg
05-20-2008, 07:27 AM
Some related information to those changing their own transmission fluid or having somebody do the work.

First, the recommended filters are the high capacity. Those filters extend the filter and fluid change interval. I think they may be all that you can get anymore, but it does not hurt to verify it. The Allison part number for a pair is 29548987.

When changing filters keep in mind the bolts around the bottom of the filter housing are steel going into a much softer aluminum pan. While there is a paper gasket between the housing and the aluminum pan, the actual seal is at the O ring beneath the filter so excessive tightening of the six bolts is not necessary. The Allison specification for torque is 38 foot pounds. Even 35 foot pounds is adequate. If you or the mechanic uses an impact wrench or excessive torque the aluminum threads in the pan are easily stripped and the repair is expensive. Keep that in mind.

When checking the fluid level the coarse initial check is the dipstick. It is very hard to read and with a cold transmission as long as the fluid is anywhere within the cold range you are alright to do a road test and get the transmission up to temperature for a final fluid level check. When the transmission is hot push the two arrow buttons on the gear selector pad and after a suitable countdown the display will read the level. It should read O L followed by O k. If it is not OK it will tell you how many quarts to add if necessary. You can check transmission fluid status anytime using this method. Do the check with the transmission in neutral at low idle.

JIM KELLER
05-20-2008, 08:19 AM
Some related information to those changing their own transmission fluid or having somebody do the work.

First, the recommended filters are the high capacity. Those filters extend the filter and fluid change interval. I think they may be all that you can get anymore, but it does not hurt to verify it. The Allison part number for a pair is 29548987.

When changing filters keep in mind the bolts around the bottom of the filter housing are steel going into a much softer aluminum pan. While there is a paper gasket between the housing and the aluminum pan, the actual seal is at the O ring beneath the filter so excessive tightening of the six bolts is not necessary. The Allison specification for torque is 38 foot pounds. Even 35 foot pounds is adequate. If you or the mechanic uses an impact wrench or excessive torque the aluminum threads in the pan are easily stripped and the repair is expensive. Keep that in mind.

When checking the fluid level the coarse initial check is the dipstick. It is very hard to read and with a cold transmission as long as the fluid is anywhere within the cold range you are alright to do a road test and get the transmission up to temperature for a final fluid level check. When the transmission is hot push the two arrow buttons on the gear selector pad and after a suitable countdown the display will read the level. It should read O L followed by O k. If it is not OK it will tell you how many quarts to add if necessary. You can check transmission fluid status anytime using this method. Do the check with the transmission in neutral at low idle.

Jon, You are a " Fountain Of Knowledge. " This post is just another example of the benifits the members of this forum enjoy through their membership. We are indebted to you and I think we should start trying to repay you for all you do. Perhaps we could all take turns weeding your garden, one week at a time through out the summer. Let me know when it is my turn.

Jon Wehrenberg
05-20-2008, 08:36 AM
I'll have a couple of semi loads of mulch to spread, by hand, one pitchfork full at a time. In the past working like a borrowed mule I have been able to move it one Gatorful at a time up the hill for spreading, usually spending four days per semi load.

If you are looking for a local charity, let me know. Bring your own pitchfork.

Or you can help polish my slack adjusters.

JIM KELLER
05-20-2008, 09:32 AM
As soon as I find my pitchfork I'll be right up !