I am hoping that someone might have some info on this. I was driving my 1924 TT on sunday when i felt a clunk and the rear started making noise. I pulled it into the garage to find out that i have no reverse. The truck is locked up and I cannot roll it backwards. When I jack the truck up the wheels spin as they should. I can start the truck and run it in 1st and 2nd, just no reverse. The motor and trans were rebuilt recently and only have about 30 miles on them. I would appreciate any advise on this.
Remove the four bolt cap on the back end of the rear end and check out the thrust bearing. You will have to pull off the big nut on the end of the worm. The three piece thrust bearing is underneath it. It's the only thing I can think of in the TT rear that might work differently in reverse. Under the thrust bearing is the worm support bearing which you can remove and peek in and look at the gears to see if they have a problem.
I'm inclined to suspect the problem may be in your transmission. I am worried that the bushings were set up too tight, I have seen it many times here, and it causes all kinds of grief. About 30 miles is common for problems with a new trans to act up. TT rear ends rarely have problems if kept properly lubed. I hope you find something simple and get back out on the road.
I'm inclined to agree Erik. That TT rear end is almost bullet-proof. How about the reverse transmission drum? Check for cracks? Then theres the U joint. I've had one break when I was a kid and didn't grease it. Didn't find out about it until I tried to go back'ards. And I've heard it said by folks on this Forum a lot smarter than me that running gear noises are inclined to change locations from the real breakage.
One more vote for what Erik and George have said. I'd be looking the transmission over very carefully.