Excessive play between pinion and ring gear

[D-rek07]

Hello everyone first time poster on here so cut me some slack. I've done a lot of research on shimming the diffs. I've noticed people putting a shim in between the bearing and the diff case to push the ring gear closer to the pinion gear. However obviously this is limited by the other side of the diff case so adding more shims will just bend the plastic out as opposed to making a tighter fit between the ring gear and pinion gear. I broke a tooth off of the pinion gear and put a flat spot on two or three of the teeth on the ring gear. How does any of the shimming ideas prevent this from happening again?

 

[Lride Chart]

Hello everyone first time poster on here so cut me some slack. I've done a lot of research on shimming the diffs. I've noticed people putting a shim in between the bearing and the diff case to push the ring gear closer to the pinion gear. However obviously this is limited by the other side of the diff case so adding more shims will just bend the plastic out as opposed to making a tighter fit between the ring gear and pinion gear. I broke a tooth off of the pinion gear and put a flat spot on two or three of the teeth on the ring gear. How does any of the shimming ideas prevent this from happening again?

This is what I am doing without issue. I am running either stock diff cups or the HR diff cups. So I can’t say anything about them working with the Arrma aluminum ones. You really need to do what is right for your rig sometimes the fitment is different. Good luck and bash on ??

 

[MrTitanium]

Welcome aboard.

Adding a shim to the pinion lowers the depth which tightens the backlash. Many swear by this, but it should also be stated that sometimes it isn’t needed. Trial and error and dry assembly will tell you if your diff(s) require this.

Feel free to search the drivetrain threads as most, if not all, questions are answered there. If there is a parricular question which hasn’t been addressed, feel free to reach out to one of our members.

 

[D-rek07]

Welcome aboard.

Adding a shim to the pinion lowers the depth which tightens the backlash. Many swear by this, but it should also be stated that sometimes it isn’t needed. Trial and error and dry assembly will tell you if your diff(s) require this.

Feel free to search the drivetrain threads as most, if not all, questions are answered there. If there is a parricular question which hasn’t been addressed, feel free to reach out to one of our members.

Well, since I broke a tooth off, I think it needs it, but even if I shim it down, the mesh between the pinion and ring gear is super loose. Like way too loose if you're comparing it to standard pinion gear on a motor to spur gear mesh. Only like half the pinion gear is engaging with the ring gear. I'm guessing this small engagement is what caused it to break. All the force is going to half the tooth as opposed to the whole thing.

 

[MrTitanium]

Please post pics so I can examine it in detail.

 

[D-rek07]

Please post pics so I can examine it in detail.

In the attached pictures you can see the wear marks on the ring gear from the pinion gear. The other picture shows how loose the mesh is between these two gears, I'm not surprised then that the pinion gear list a tooth. That's a lot of force on a small part on that pinion gear tooth

 

[bicketybam]

Mine is about the same and I have had that happen im almost 2 years. That's weird.

 

[D-rek07]

Mine is about the same and I have had that happen im almost 2 years. That's weird.

I think yours has more engagement than mine, but I don't really know how much 0.5mm more engagement is doing. Maybe it was just a bad part. Do you know of any bad driving habits that can cause this?

 

[bicketybam]

I think yours has more engagement than mine, but I don't really know how much 0.5mm more engagement is doing. Maybe it was just a bad part. Do you know of any bad driving habits that can cause this?

Standing blackflilps. Landing under throttle. Landing under brake.