So the AX 15 holds a gallon?

 

It's about 3.5 quarts, so you'll have a little left over.

 

Is it OK to over fill it a little bit, that's what I do with my ZF6.

 

I wouldn't. You would have to fill it from the shift tower though since it uses the same fill/drain plug scheme as the transfer case. I've always heard that "too much" is always worse than "slightly under" when dealing with oils.

 

I always fill them through the shift tower, much easier. Most people recommend overfilling the ZF6, NV4500, NV5600, and G56 transmissions, I wasn't sure if the AX15 was the same way.

 

Hmmm, I've never heard of a recommendation for overfilling the AX15. For a long time I felt that overfilling the NV3550 in my TJ contributed to it blowing a bearing, but recently I think improper pilot bearing installation may have been more of a factor. Maybe folks with more knowledge or experience than I can speak to whether it is beneficial or not.

My Dad put 400k on an AX15 and never had a problem with it - filling it just to spec. In fact he only needed 1 clutch replacement during that time. My 95's AX15 (as far as I can tell) has something like 300k on it and it shifts and drives great with MT90 filled until fluid started coming out the fill hole. It wasn't bad at all filling it with a standard fluid pump. Had I not had one handy, I definitely would have gone with the shift tower fill.

 

I wouldn't overfill it by much, if any. The normal fill level on them is quite high relative to some other transmissions. I just pull the fill plug out and dump it in from the shift tower until it starts running out of the fill hole.

 

I ended up dumping a gallon of 15w40 Diesel oil in and is doing good so far.