Normal Diff Pinion Wear

[BobTeagle]

I had a Team Associated Rival last year. It's a little bigger than the Savage XL. It had diffs about this size and was a 15lb truck but I never had an issue with the diffs. Even on 6s! Axial needs a new bulkhead and XL sized scorpion gears. Thier 1/10 scorpion gears are hardened steel and spiral cut gears. Since they offer those for 1/10 maybe there in the works.. I am going to message Dhawk to see if they can do an aluminum front gearbox.

[BobTeagle]

I messaged Dhawk racing and they are going to make aluminum front gearbox for the XL. He said it will take some time. Maybe aluminum gearbox, diff case, and spacers between the pinion bearings will eliminate the flex. I'm gonna give axial an earful today when I call them. Like previous poster said, I like rc problem solving but these diffs are too weak to fix. Axial needs to provide spiral cut hardend steel ring and pinion gears for all owners who have had this happen. Only two 4s runs on my front lawn taking it easy should not have caused issues.

[BobTeagle]

Well the support guy at axial played dumb and said he has not heard of this issue yet.. lol. He is sending me a new set of gears and a new front bulkhead in case mine was defective or warped. I have ordered dhawk racing aluminum spacer to go between the pinion bearings and a hot racing aluminum diff case.

I asked Axial about spiral cut scorpion gears for the XL and the guy said he would mention it to the design Team.

Dhawk and Hot Racing have an aluminum bulkhead in production

Maybe with enough money thrown at this thing it will be trail worthy...

[fornowagain]

Has anyone tried doing away with the middle spacer between the two bearings? Looking at the bulkhead and pinion, you could just use another 15x21x4mm bearing in the middle to make a more solid 15x21x12mm support? Or what about a 15x21x12mm roller bearing? It would be a hell of a lot stronger.

[BobTeagle]

I thought of that but when I put the 15x21x12mm bearing up to the spacer the bearing was not as thick. If you had enough shims it would work. I ordered the steel spacers (dhawk raing on ebay)

[fornowagain]

With a vernier/mic, can someone please measure the width of the two bearings and the spacer as one piece? And the spacer and bearings separately? Don't have a kit here, thanks.

[BobTeagle]

I went ahead and put it back together yesterday. I figured if I have new gears on the way I might as well have fun as is. After reassembly it has not clicked once...

I am stumped here. Apparently there was an issue with the way it was assembled the first time. I have been assembling rc kits for over 20years and never had a problem like this. I am not say it wasn't my fault, but I was very careful when building. One note of mention.. After watching fast eddy's build I was trying to be careful not "over tighten" when assmbling the 1st time. When I reassembled I cranked down the bulkhead screws a little harder thinking maybe it would bring the diff closer to the pinion. After all since Axial is sending a replacement bulkhead it would not be the end if I stripped it out. Maybe by being careful not to over tighten I did not have it tight enough.. Anyway, maybe this can help someone else.

[Dionisi]

Oh boy, reading these older posts is pretty worrying, hearing stories of this truck being put back together and getting different smoothness is bad news. Design is difficult yes but quality of parts can solve a lot of issues. A truck this size and weight needs super stiff parts in the right areas.I used to race 8th scale onroad and the plastics are so good and screws etc are beefy, you could rebuild it over and over and it there would be no slop. Should be no different with these huge bashers. Initial cost is what ruins everything. Say the yeti xl cost 1 grand even that would just make everyone panic and complain. Yet people would buy it for 700 then have to constantly buy diffs and parts equalling much more in the long run.

[BobTeagle]

After using fast eddy bearings, Dhawk pinion spacer, hot racing diff cup, and shimming properly I had no issues. I think the stock plastic diff cup and plastic pinion spacers flex and cause improper mesh while under a load. Just to be safe I installed the Dhawk aluminum bulkhead as well. Just to eliminate flex. The rear seems to do well with just fast eddy bearings and Dhawk pinion spacer. The rear axle plastic is thick enough.

[Dionisi]

Hey Bob can you show me a link for the dhawk pinion spacer, thanks.

[BobTeagle]

Aluminum Bevel Collar 2 Pcs Polishing for Axial Yeti XL 90032 Dhawk Racing | eBay

[Dionisi]

Thanks again.

[relay1]

I just pulled my front and rear diffs apart to find a tooth missing and teeth worn down on my front ring gear, rear ring gear also has worn teeth Pinions also looking a bit worn in. This explains the recent clicking I've been hearing. But what I'm hoping is that the real culprit for all of these diff wear issues is actually the slipper clutch. I ordered the robinson racing 1/10 clutch which is supposed to work according to this thread

Robinson Racing Gen 3 slipper for 1/10 Yeti works.

[pro mod steve]

I installed the RR 1/10 slipper on my kit and it was painless. No test yet as my motor and esc will be here Tuesday. I just did not like the looks of the factory slipper frictions and reading about them galling and siezing up.

[cmbscx10]

Originally Posted by relay1

I just pulled my front and rear diffs apart to find a tooth missing and teeth worn down on my front ring gear, rear ring gear also has worn teeth Pinions also looking a bit worn in. This explains the recent clicking I've been hearing. But what I'm hoping is that the real culprit for all of these diff wear issues is actually the slipper clutch. I ordered the robinson racing 1/10 clutch which is supposed to work according to this thread

Robinson Racing Gen 3 slipper for 1/10 Yeti works.

The RR upgrade will help but from what i have read, the Diff's blowing have been from the bulkhead and plastic shims. I wouldn't put either one back together without the upgrade. When i blow mine i will do upgrade no if's ands or but's. If i don't have the funds it will sit till i do.

[relay1]

Originally Posted by cmbscx10

The RR upgrade will help but from what i have read, the Diff's blowing have been from the bulkhead and plastic shims. I wouldn't put either one back together without the upgrade. When i blow mine i will do upgrade no if's ands or but's. If i don't have the funds it will sit till i do.

Agreed. I actually picked up the vanquish rear axle, dhawk front bulkhead, dhawk spacers, 2 new ring and pinions (that makes 4 replacements so far), and new front and rear diff cases. This along with the RR upgrade I sure as heck hope will fix the diffs from failing! Hope to have it all installed in the next couple weeks.