Anyone else have this problem? 4EAT disengages at stops.

[tahiti350]

Wife's 90 Lego Wagon, swapped in a used trans last October (180K miles) due to the transfer case failing. The new to it trans worked okay, little laggy on the 1-2 shift, but okay other than that. Now when you stop at a light or in traffic, the trans effectively goes to neutral. It is still engaged, but will roll backwards in drive, or forward in reverse. If yo give it just a bit of throttle it re-engages and away you go as normal. Not slipping at any other speeds.

Fluid has been changed twice, but is not discolored, burnt, or anything. Changed it the second time just to make sure everything in the pan was kosher (no loose or mis-connected lines, etc).

One benefit is that She has picked up 1-2 mpg around town...

Help...

Need to add, when cold the trans goes right into gear and works normally, after it warms up it starts acting up.

[Legacy777]

It may be due to low line pressure which could be caused by a number of things like leaking seals inside the valve body or shift solenoids.

Without some more information or troubleshooting it'd be a bit difficult to know for sure.

[Alphius]

Agreed, symptoms of low line pressure.

[tahiti350]

Okay, so what t/s'ing can I do? Would it be possible for it to be the trans inline filter??

Have a donor car here now, cleaning out the garage so I can pull engine and trans as a unit, and swap it into the wife's. Her's is over 250K, and almost 100K since we got it, still haven't even changed the timing belt...

[tahiti350]

have replacement engine/ trans hanging in the hoist in the garage now. Going to clean things up and swap it in... once I check it out I'll take care of oil changes, timing belt, cam seals etc. would do all of it while it's out and easy, but don't want to put a bunch of money into it and find out it's worse than we had to start with.

[Legacy777]

Are you talking about the filter next to the radiator on the frame rail? If so, I kind of doubt it.

[impostor]

I would check line pressure before throwing any parts at it. Also pull the pan to inspect the screen for clutch material and physical condition. I just had one that had a broken neck where it goes in to the pump suction hole. It was a cheap chinese screen. In my past experience at a transmission shop, problems when hot are usually terminal.