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View Full Version : AW4 problem for the Guru's


old_man
October 23rd, 2006, 08:09
Ive done a lot of tranny rebuilds and have broken a few tranny's over the years, but this one is a bit wierd. I was in Moab wheeling the new rig. It worked great. I finished wheeling for the day and drove about 5 miles in 2wd on the highway, then came to a complete stop. Up to this point everything had worked flawlessly. I got on another highway and accellerated hard and held down the gas pedal. Everything seemed fine but it didn't shift up. I let off of the gas for a second to promote a shift up and the tranny went into freewheel. There were absolutely no bumps, grinds, jerks or noises when this happened.

I have no forward or reverse gears. The tranny will hold the vehicle when in park, so the tcase is not the problem. After pulling it back to the campground, I pulled the tranny cooler line and put it in a gallon jug. I started the engine for about three seconds and ended up with a half quart of fluid in the jug, as I hoped. Just for grins, we pulled the inspection plate and the TC bolts were all fine, as expected from the above test. There were no leaks.

I pulled the pan, there was absolutely no debris in the pan. It was clean. I went ahead and replaced the filter with a new one and buttoned it back up and replaced the fluid. Still nothing. I pulled the tranny computer connector, still nothing. So I said screw it and pulled it home.

My best guess is that I have a piece of something causing a valve or solenoid to stick in the valve body.

Has anybody else seen this? If so what was your solution?

Anybody know where to get a gauge to measure the pump pressure on an AW-4?

old_man
October 24th, 2006, 14:51
A tranny specialist buddy says it is most likely the sprag clutch.

Anybody got a spare AW4

90Pioneer
October 24th, 2006, 18:24
I had something real similar on my jeep happen. 96 4.0 with AW4. If you got past 20mph the motor just revved.

Replaced TPS and it was good as new. This happened after I went through a lot of water. Definately replace the TPS before you replace the trans.