Allison Tranny Fluid

rkenly wrote:
i just bought a new to me coach.
it is a 1998 chassis
since im not home right now, dont know which allison it has.
however when i did my walk around, it has a big sticker that the dexron 2 fluid has been replaced with engine oil (15-40).
the dealer indicated that a lot of coaches did this to have smoother shifts?
is that because of dextron2 vs newer dextron 3, or transynd?
better to just leave it, or upgrade to transynd?

tia
>>>Rod<<<

Well Sir, in all my mechanic life, I've NEVER heard of replacing ATF with engine oil, in any automatic trans, no matter who the maker of the trans was/is.

As for using Dexron II or, III, most Allison trannies came with Dexron II or III but, a few, were outfitted with Transynd, right from the factory. Mine is the Allison MH3000 and our coach is an '04 Itasca Horizon 36GD with the CAT C-7 330HP and like stated, the Allison MH3000. If I'm not mistaken, the Allison 2000 models came with Transynd. But, to be sure, dig up your vin and call your chassis maker and you'd probably be able to get info on what your coach was originally outfitted with.


Ours came with Dexron III and, a while ago, I did the complete change-over to Transynd. That was a bit expensive for the first change but it's supposed to last almost 100K before another trans fluid change.
Scott