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Allison Fluid and Filter change questions
I don’t know when the filters/fluid was last changed so I plan on replacing them before the next long trip. But before I order parts I thought I’d check with you guys.
I looked at the Prevost Parts site but I’m not certain which filter kit to get. My chassis is a ’97/’98 with VIN W2663. Does my transmission have a 2″ sump and is this P/n 29548987 the correct filter kit?
Also how many quarts/gallons of TES-295 (Transynd) fluid should I expect to replace?
I’m planning on doing the hopefully not too dirty deed in our driveway
Thanks, Gerald
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11 Replies
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Gerald,
My memory says 7 gallons. Whatever the books say is not necessarily accurate because you cannot replace any more than you take out and some is retained, such as in the intercooler.
29503829 is the filter number I show from my records. That’s the Allison number and you need to really verify it because there are two lengths of filters and there are two levels of filtering if I recall.
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Talk to Allison Gerald with your tranny number and get the torque specs for the bolts. You want the filters to go back in and flush by hand, do not attempt to pull the filter housing in with the bolts.
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And DO NOT remove the filter bolts from a hot or warm transmission…cold only. Prevost tech removed one bolt along with the threads from the case of my warm trans and I was told by the more senior Prevost tech this is not uncommon. There is a repair kit, but…
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To Joel’s post, use anti seize compound on bolt threads anytime the bolt and whatever it is threaded into are of dissimiliar metals or anytime they are stainless steel. I’ll bet most oil change techs don’t even know what it is.
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Just a few clues for the first time you drain and fill your own transmission. The fluid will come out of the filter housing in a most impressive manner so barely loosen the bolts and with something jar the filter plate loose. Let the fluid seep out of the resulting little space. When it stops dribbling then loosen all the bolts and remove the filter.
Do not overtighten the bolts. That aluminum case and the threads can get damaged real easy. Same with the drain plug.
The most accurate way to verify the correct fluid level is the use of the two arrow buttons on the transmission shift pad. If you are into pain try reading the dipstick. When you get frustrated you can always use the shiftpad.
Use Transynd or its synthetic equivalent. Don’t try to save money by using Dextron.
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Do not use any type of power bolt driver, no matter what!
Use only hand tools and be aware of the correct “feel” of the threads.
If you strip the threads there is a repair kit from Allison, but I think it is in the $14000 range. The kit entails a special jig and helicoil inserts.
JIM
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just a drain pan note. I use a container from Home Depot made for mixing mortar. They are fairly flat and hold more tha the transmission or cooling system
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Thanks for all the tips. I’m sufficiently paranoid about the filter cover bolts-will treat them with respect.
I cleaned several years worth of grime off the transmission sump to id the two filter covers and the drain plug. Now I’m just waiting for the filter kit and the fluid.
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The weather improved and I finally changed the Allison transmission fluid. The drain plug was really torqued down – so bad that I bent the head of a (cheap?) socket extension. But it did let go finally. The tip about using a Home Depot mortar mixing tub worked great. No spills. I’ll use it on my other cars as well.
The old filters were manufactured 3/05 but the fluid looked pretty good. I drained 7 gal and refilled the same amount. I’ll use the shiftpad to double check next time out once the transmission is fully warmed up. Not a bad job overall.
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The tech at Prevost Jax told me to only add 1/2 of the amount that the shift pad tells us to,if it tells you it is 2 quarts low only add 1 and then check again and mine was full.
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Overfilling a transmission is something to be avoided. Generally if it is overfull it tends to heat up which is contrary to what you would think.
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