2000 silverado 4x4 with 260,000 miles, motor is freshly rebuilt with cam and other mods to motor, transmission is freshly rebuilt with with performance parts and shift kit, and transfer case has had a basic rebuild bearings seals. It is a np261 manual and the problem I am having is the snap ring on main shaft keeps breaking, this is the second time and it's happened both within a month of fixing. I didn't have this problem before I lifted it (6" on 22s and 35s). Transmissuib shop I use said that to fix the problem is to replace the rear case half because the groove the snap ring sits in is worn out and is giving the ring more room to move around and breaking. Does this sound right to y'all? I don't wanna keep having this problem. Thanks.