Transmission problems

My wife has said that this has happened a few times to her but this time I was in the car with her.

It is a 96 4x4 sport 231 with AW4.

We got of the freeway and stopped at a light. She went to accelerate and the jeep started to move slow with the engine reving once it got over 15 miles per hours it ran normal. We pulled over put it in reverse and it backed up fine, put it in drive and it was slipping again. It felt like it was trying to take off in second gear. We parked it, came back to it a few minutes later and it drove us back home normal. I checked the fluid levels and they were good.

What could be the problem? I changed the NSS about a year and a half ago and the trany fluid was changed about 1 year ago.

Also if I need to get this fixed do you guys recomends a jeep dealer or a indy transmission shop. I cant do much mech work, I broke 2 vertebrea a few months and live in NYC so I cant do anything myself.

Did you check the trans fluid with the Jeep running and in P or N...on a level surface.

What does the fluid look/smell like??

Sounds to me like low, wrong or old fluid...are you using Dex or ATF+4.

I was level and run in gear when I checked it, the fluid is about a year old DEX. Also if the fluid was bad/low why would it run fine in reverse?

Pump pressure is set to a higher number in reverse. Working in reverse and crappy forward is sign of a pump seal that is getting old. Put a cup of lacquer thinner in the tranny fluid or buy a can of the off the shelf tranny fixit. They both soften the old hard seals and help the pressure that the pump can develop.

^^^What he said!!

...The reason I ask that is that I blew a tranny cooler line on the trail, 20 miles from...well...civilization!

I left a trail of fluid about 1/2 mile long, say the guys behind me. The only symptom was that - the engine was running (and revving) and it was in D or 3, but it just wouldn't go. 4 qts is what it took to get the torque converter back up to speed. As it was I limped home the 35 mi.

But why does it (the slipping)go away sometimes by itself or when I come back to the car later and then it drives fine for months?

Thanks for the help by the way.

sleestack said:

But why does the slipping go away sometimes by itself ....

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Sounds more like an sensor/electrical issue. TPS, NSS, TCU or wiring.

Test the TPS, adjust the NSS.

If you buy a TPS, get a quality part from JEEP or NAPA. Cheap TPS from the big name auto parts stores have been proven to be out of spec or even dead right out of the box

sleestack said:

But why does it (the slipping)go away sometimes by itself or when I come back to the car later and then it drives fine for months?

Thanks for the help by the way.

Click to expand...

Its not uncommon for the seal to flex and change as it warms up and cools down. A seal is designed so that the pressure it holds back actually helps increase the mating pressure, so if you can get the pressure to spike and the seal to warm up, the seal may mate up better and it will tend to stay mated while the pressure is maintained. Softening the seal makes things work better for a while.

And just to let you in on a little secret, transmissions are female.

Im leaning more toward the nss or tps problems but I'll look into the seal softener just to be safe.