Hi. I'm new to the 4R world, but I had a Tacoma that I replaced the diff bearing on the driver's side with a bushing from ECGS. Results were great ... Decreased play in CV shaft at the diff and elimination of the cyclic whirring / vibe that was from the worn needle bearing.
Is this a problem with the 4Rs as well? If it's similar, I'll be ready to repeat the repair on my newly acquired 4R.
The bushing was longer with tighter tolerances than the needle bearing... much more stable.
---
Matt