I have an intermittent issue and I was hoping this thread could help me narrow down the cause.

When I come to a complete stop my transmission feels like it disengages something. It actually shakes the whole jeep when it happens. The first time it happened I thought someone bumped into me in traffic. When it is disengaged and I let off the brake the jeep doesn't pull itself forward. It just sits like its in neutral.

Sometimes after just what seems like only a second I feel it shake and re-engage and i'm ready to roll again.

When I do gas-> nearly stop-> gas (ex: when I pull up to a red light pause a split second and then back into the gas) the jeep seems to just rev up and sit still (like its in neutral). I actually have to let off the throttle and I feel the jeep shake and engage and then I can get back into the gas and actually move.

All of my transmission related experience comes from front wheel drive vehicles so I really don't know where to begin here. So, if anyone has a explanation or something I can check to rule out some possibilities please post here so I can check them. I haven't checked the ATF in a couple days but it was okay last weekend when I checked and I have no major leaks in that system.

 

Venturing a guess here, but it sounds like you're describing low fluid level symptoms. Since you said no leaks, and fluid wasn't low last week, then I'd think a plugged up filter, or such that would mimic the symptoms of low fluid. Possibilities that I would think is plugged or restricted filter, or an internal fluid pressure leak, of a failing front pump. I've never been inside of the AW-4 (I'm assuming you have an AW-4), but this is what my limited transmission building experience would suggest. I think dropping the pan for a filter change, and a quick look-see, would be my first suggestion.

 

*What is the history of routine fluid changes on this transmission? Fresh fluid goes a LONG ways on transmission behavior. And of course, verify fluid is at the correct level on the dipstick with a hot, fully exercised engine and transmission.

*What is the color of the fluid? It should be "red". Any other color necessitates replacement!

*Smell the fluid. Does it smell burnt? Burnt fluid also needs to be replaced

*Any doubt, change fluid. Use Dex/Merc III compatible fluid.

*How many miles on this transmission? If fresh fluid doesn't help and you have no OBD codes, you may have an internal problem.

 

I'm going to check the levels again to be sure. With all the fluid brand new its sometimes hard to see the level on the stick. I just went through a whole trans cooler line and connector fiasco and those are finally fully replaced and leak free. I've watched the fluid a lot in that whole process but if I was misreading the level then it possibly could be low.

As far as the filter/tranny pan i've wanted to do that service for a while. No clue if it has ever been done to my jeep. The trans cooler lines caused me a ton of issues and sort of killed my motivation to work on the xj. Is that tranny filter difficult to remove? I've never done a pan job on any vehicles of mine.
No clue on trans service history. Since i've owned it (2008 - current) it has had a steady leak from the trans cooler lines which pretty much kept fresh fluid always going in the thing. I always used the dex/merc stuff. That issue is fixed now and the fluid is brand new for the most part. No burning smell. Mostly pink/red color although I don't know if it's circulated around enough to pick up any discoloration yet.


So both of you think its my transmission too. Is there any way to rule out that its not something else in the driveline, like the transfer case?

 

yep it was fluid. After watching a few more days I realized I was still lower than I thought so I added until it was happy and it hasn't done it since.

 

Does happy mean the proper level on the dipstick? It is VERY important that you don't overfill with tranny fluid. Creates a frothing / incomplete lubrication situation.

 

What he said.

Check it hot, in neutral and make sure it is at the correct line on the dipstick.

 

yeah it's at the proper level now. I thought I was all set but I had to check it a couple of times with everything warm to get a real idea of how much was in there. I topped it off and its pretty much dead even with the top of the hatch marks on the hot side of the dipstick. I *may* have like a cap full of extra fluid but I don't think its anything to really worry with. It's definitely not crazy overfilled.

Back when this thing was leaking tranny fluid like crazy I would just dump fluid in there and a lot of times I probably overfilled it knowing it would just leak back out. So I hope I haven't shortened my poor transmission's life. It barely survived the last owner in the mountains.