Basically, when the car is in OD and I'm leaving from a stop (hard acceleration or soft) the engine RPMs climb but the wheels don't seem to match the output. The car starts to slowly move while the RPMs increase fast. They will get to say 3000 and then the car will change gears and I can feel actual acceleration. The way I've found to deal with it is to give it heavy throttle and let off, then get back on it. This only happens in OD. If I put the car in 1st, 2nd, or 3rd, it'll drive just like it should. The car is currently in storage for the winter, but I'm looking for items to check (valve body, sprags, etc.) I've read lots of different threads but no one seems to have this problem or atleast an answer to it. Any help or ideas are much appreciated. Thanks

 

Anyone have any ideas? Troubleshooting transmissions isn't my thing. I'm looking for a list of things to check, probably that function in OD only.