I had something unusual happen to the rear end in my 1955 TR-2. I was in college and headed to Daytona Beach for Spring Break. In Northern Ga. I ran into a heavy rain storm; didn't bring my side windows on the trip. After the storm passed, I started back and my wheels started to slide in the mud. All of a sudden I heard a crunch and the car came to a quick stop. When I tried to start again, it was like being out of any gear. Left it at a All Night gas station; people were honest back then. After towing it back to Atlanta, I removed the rear end cover plate and discovered a hand full of spider and axle gears along with teeth missing in the ring and pinion gears. I replaced all the bad parts and things were back to normal. Next Spring Break, I was careful driving through Roberta Ga. scene of the crime the year before. After lunch, in Roberta, we started off again and I immediately hit a bad pothole. Yes, you guessed it, took out just the ring and pinion this time. Back to the same gas station, same attendent.
Now it's been two years, I have graduated and am heading for Miami for the summer. You guessed it! right outside of the fateful town of Roberta, I went off the road into heavy mud. Yep, another crunch, but this time I was able to drive it to my favorite gas station. Upon removing the rear end cover, I discovered one of the ring gear bolts wedged in the pinion gear. After it's removal I was able to make it home. After conferring with the triumph dealer in Miami, I was told the this particular rear end suffered from alot of play, when under duress. Apparently the locking tabs on the ring gear would contact the case and shear off a tab. Then that bolt would become loose and airborne shortly afterward.
The dealer felt sorry for me, having gone through this problem three times, he gave me a new ring and pinion gear along with ring gear bolts that were pre drilled for a safety wire.
No more Problems with the rear end up until I traded it in own a Porsche.