I have just had my transmission built to a stage 3 spec from a local guy here in socal. Drove it about 150 miles with no issues. I drove it today to the tune shop and it started to do some weird stuff in reverse. It would roll back about 5 to 6 feet then come to a complete stop ,But it would start moving after 2500 rpms and acting like the parking brakes was on.
Then put it in neutral and it was wanting to jump forward. Drove the car in drive and did some wot pulls on the street it was fine but reverse is still doing the same thing. We made about 7 pulls with no issue with the tranny.

Do you guys think that the trans is the problem?

 

Sorry that no one replied earlier, but it seems rather obvious that the trans has an internal problem. Assuming you paid for it, the rebuilder should be taking care of it.

 

Does it take off in 2nd gear while the shifter is in Manual Low/1st...... If so, The Center Support Snap Ring blew out of the case & the support is pushing against the Sun Shell in Reverse (Bind) & Manual Low (2nd Gear Start).

Reread the post.....If it drives forward in neutral, The Forward Clutch is stuck on.