I'm a motorcy and outboard tech. And must shim most all outboard lower unit gears. And atv differentials. Its called gear mesh clearance. Too loose will wear gears to quickly. Too tight will cause binding and excessive heat and oil deterioration.
This video was very helpful. I have the same grinding noise from the rear differential of my Losi TLR 5ive-B buggy I recently built. I first removed the included rear diff pinion shim because I knew the mesh must be off slightly. After removing the included rear diff pinion shim the grinding was a little better but not smooth like it should be. Just like you mentioned coming off the throttle the buggy slows down some because the mesh tightens up slightly as the gears warm up. I didn’t think about shimming before out drive cup bearing on the crown gear side to create a better mesh. I have the exact shims needed, they are made by Axial. On my next rear diff service I will try shimming before the crown gear bearing, I know this will solve my slight grinding issue in the rear differential. Thanks for sharing this awesome information!
I did the same thing like you did and it made mines worse!!!! So then i thought why not shim the diff to increase the mesh between the diff and the diff pinion. I was able to add a plastic that works kind of a shim and it worked perfect. NO MORE GRINDING!!!! So, i ordered some shims. I think they are made out of stainless steel. They will last a long time. But stick around for my next video. Im just waiting for the shims to arrive
The video with all the mods and tuning is uploaded. In the video i do test runs on concrete, gravel and duirt. The outcome is awesome! Please check the video out when you get a chance thanks
