trannys problem (aw4)

When I first got the jeep I put a new (used 80k miles) tranny in it and for a couple hundred miles it drove fine (after I got the TPS adjusted) and then on a trip it started jumping down a gear at 70MPH. It did this about 3 times on a 100 mile trip (highway driving). Now it will not shift out of 1st. Sometimes it will come out of first after everything is heated up but it still jumps around. I checked the fluid levels and they are fine. Does the aw4 have a vaccum modulator? Or anything vaccum related? I am trying to not have to pull the transmission again. thanks


-Dillon


EDIT: 1990 xj laredo 4.0 aw4 305k miles (2-300 miles on "new" tranny pulled at pick-a-part with 80k miles on it)

TMNT said:

When I first got the jeep I put a new (used 80k miles) tranny in it and for a couple hundred miles it drove fine (after I got the TPS adjusted) and then on a trip it started jumping down a gear at 70MPH. It did this about 3 times on a 100 mile trip (highway driving). Now it will not shift out of 1st. Sometimes it will come out of first after everything is heated up but it still jumps around. I checked the fluid levels and they are fine. Does the aw4 have a vaccum modulator? Or anything vaccum related? I am trying to not have to pull the transmission again. thanks


-Dillon

Click to expand...

What year?
The AW4 is electronic control, the TV cable acts like the vacuum modulator along with signals from the TCU and TBS. Shift ranges are selected buy the NSS.

Someone needs to make a acronym converter...haha...its a 1990



-Dillon

What'd the fluid look like when you pulled the tranny from the yard? I'd guess a solenoid is sticking or some junk is keeping fluid from flowing through the valvebody correctly.

Also check the fuse under the dash on the passenger side. Should be a 7.5 amp fuse if I remember correctly.

ok...i still havnt messed with the tranny but it is working fine now...I am guessing it is like what wobbles said and there is junk built up. I am going to flush it and change the filter and see if that helps. The fluid seems level and fine right now (never been low or anything)


Another thing. My power steering is startin to whine really bad. the fluid looks level but it milks up and is pretty thin like it has water in it. It also smells a bit burnt. What is the best/easiest way to drain a power steering pump?

thanks a bunch fellers



-Dillon

Pull the return line from the steering box to drain it. Low fluid, air in the system will make the pump whine. If it continues after fresh fluid/full & bled, the pump bought it. Not saying to change it, just that the life expectancy will be much less.

An air leak at the top of the return line will introduce air without showing a leak or draining much.... Check your lines for cracking or aging too.

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