Having an odd issue with the 904 in my Duster. It is about a year on the last rebuild, with approximately 5000 miles since that time. The problem is with gear selection. When I go to start it in park, it will do so, but lunges forward a bit and acts as if it has a load on it when I rev it, much like it is stuck partially in a forward gear. When shifted to reverse, nothing occurs, maybe slight forward movement. Neutral will allow engine starting, but again, it lunges forward at bit when it lights and acts as if there is a load on it. Drive will move the car forward and it should shift ok. First and second gear should be ok. Why is this?

I tried adjusting all of the linkage down on the trans to no avail. Next, I disconnected the linkage and moved the shift lever on the trans by hand. Each gear selection clicks as it should, but when I go to start it, same thing...its acts like there is a load on it and there is no reverse even in reverse!

The fluid is clean and full and doesnt smell burnt.

I am at a loss. Could there be a governor inside thats clogged, or linkage falling apart just inside the trans? Something in the valvebody?

Interesting thing to note is that it did this last week after a 20 mile drive to work on the highway and when I went to put it into reverse to park, same issue. I let it cool off and crawled under the car to play with the linkage a bit. This was about two hours later and when I tried it again, it went back to normal for the rest of the day. This time, it is in the garage and everything is cold. Three hours of tinkering yesterday yielded nothing.

Any suggestions?

904's are good for breaking reverse bands, you will have to drop the pan to see

Lunging forward in Park/Neutral and a balky Reverse are signs of a rear clutch that's not fully releasing. Can't be fixed without removal/disassembly.

Took out for another drive and it was the same. Did a couple of brake stands and low and behold, the trans starts acting normal again, reverse and all. Took it home, dropped the pan and flushed the fluid and changed filter. Still ok currently. My hunch is that when the converter grenaded a year agom the trans shop didnt completely flush and clean out the trans, allowing crap to stay in the valvebody. I cleaned it out as well. There was some shavings (probably from the old converter) and normal wear clutch dust. shifting perfectly now and nice and firm. Will keep an eye on it and probably flush the trans again soon.