The ring and pinion gears locked up on me. I decided to replace the whole rear e

Hello, replacing your rear axle / differential should not affect in any way the transmission operation. It is possible that when the rear axle locked up per your description that it could have caused other damage to your drive train due to the stress on the transmission. It sounds like far more than a torque converter problem.

Couple of questions: Is this vehicle all wheel drive / four wheel drive? Is the replacement differential ‘gear ratio’ identical to the original??