Normal Diff Pinion Wear
 

Does this look like normal pinion wear, or is it possible that I should remove a shim? Or should I try something else? I'm using the recommended 2 shim per pinion gear setup from Axial. It seems a bit notchy to me though, especially when I try to roll the yeti back and forth.

https://farm8.staticflickr.com/7443/...92e6967570.jpg

Re: Normal Diff Pinion Wear
 

I'd suggest removing one shim it looks like the pinion is too deep appears the ring gear is contacting the bottom valley between the teeth of the pinion. When rolling the truck back and forth by hand the notchy feeling is most likely the motor magnets but could be a combination of things trans diffs and motor. When you roll the rear driveshaft by hand with the two shims installed and not connected to the trans is it notchy? If so then its probably the pinion depth is too deep. Just my $.02"thumbsup"

Re: Normal Diff Pinion Wear
 

I think you're right you can see on the ring gear the teeth look to be hitting the valleys between the pinion teeth. Though the notchiness goes away when I disconnect the rear driveshaft from the trans and roll it by hand. Still though it seems the mesh is too tight so I'll try removing a shim and see how that works.

https://farm9.staticflickr.com/8637/...b71c7d5afc.jpg

https://farm8.staticflickr.com/7430/...dea39da6f1.jpg

Re: Normal Diff Pinion Wear
 

I'm sorry...the diffs in this thing are not up to scale. My front is stripped again. Axial is mailing me a replacement but it'll strip again. The diffs should be larger. The diffs in my Nitro Maxx are 1/8 hot bodies and are helical cut. After killing two sets of the small traxxas brushless Emaxx diffs I upgraded to a correct size. I have gallons on them ...and now on a Picco ....no problems at all....Maybe this rig needs 1/5 scale diffs or a front bulk and rear housing that will accept that size diff.
Also... The front shaft is too long. The doggone pin should be centered in the trans cup but the damn thing is almost bottomed out in it at rest. So under I forward flex the pinion just gets jammed into the front bulk and slams into the ring gear.

Re: Normal Diff Pinion Wear
 

I've gone through 2 ring and pinion gears at 38 a pop, and I'm afraid this one may need replacing pretty soon. Also tried replacing the front bulkhead but that doesn't seem to be the issue. We'll see if removing a shim will help. I haven't run it on 6S yet and I'm definitely afraid that will wreak instant havoc on these gears. I might see if Axial would reimburse me for the cost it's pretty hefty a price I've been paying.

Re: Normal Diff Pinion Wear
 

I don't have issues with the rear. It's the front. An aluminum front bulkhead and a front driveshaft that is similar to the rear might be the fix. Any jumping causes the gear crash I guess. Land on the rear wheels you OK. Come down on the front your not.

Re: Normal Diff Pinion Wear
 

This is my experience aswell. Landing hard on the front with some throttle. Blowing through spares like candy on this model. But atleast I do it with a smile on my face :) (until it breaks again and Im like pirateaaargh!)

Re: Normal Diff Pinion Wear
 

i agree front diffs are problematic,both my buddy and i broke front diff parts today. 1 shimmed the other not:roll:

Re: Normal Diff Pinion Wear
 

I'm going to see if I can fab up a rear drive shaft to fit the front. A slipper shaft would eliminate the chance of the pinion getting stuffed into the front bulk/ring gear area.

Re: Normal Diff Pinion Wear
 

The diff issues people are having is the only reason I have not pre-ordered the XL kit yet.

Re: Normal Diff Pinion Wear
 

I'd still get it. I don't regret buying the RTR. It needs mods but that is my favorite part of the hobby. Fabricating something and seeing it work. I came
Very close to getting a Losi DBXL but got the YXL instead. I like it a lot. The front diff issue will be solved probably right here. And I thinknis caused from 6s jumps
Landing on the front tires. And my front tires are not stock!

[IMG]http://i1383.photobucket.com/albums/...zyqblagr-1.jpg[/IMG]
[IMG]http://i1383.photobucket.com/albums/...zbdk6r91-1.jpg[/IMG]

Re: Normal Diff Pinion Wear
 

I enjoy tinkering and getting into the problem solving, tear down, build back up, fabricating parts etc. But I don't like trying to solve this very expensive problem. I do think Axial has been trying to solve the problem themselves though, some evidence may be the front bulkhead re-design. So, it's possible that the new batch of RTRs and the Kits that will ship already have the issue solved. I wish I knew. I especially wish I knew definitively how to solve the problem. I just want to enjoy driving it without worrying if every minute of run time is costing me $2. All that said, I do think it's an amazing, one of a kind vehicle. Also, just like real cars I think the early models coming off the line inherently will have more problems than later more refined models.

Re: Normal Diff Pinion Wear
 

Well I can now join the party...blew out my front diff today. After tearing it down I also noticed all the diff fluid leaked out. There wasn't any in the diff when I opened it just a light coating on the gears. Would explain why front end always seemed to diff out on rocks. Gonna be ordering replacements soon anyone have any experience with the hot racing aluminum diff bodies are they worth it?

Re: Normal Diff Pinion Wear
 

40-50 packs through my RTR both 6 and 4s never had any thing break other than shock caps from shit landings on 25 meter long jumps
stress less
get one and enjoy it . its the best rig ive ever used

Re: Normal Diff Pinion Wear
 

Even with it's terrible torque twist? It may have well been named the axial tricycle. If someone can explain why it made sense to put a swaybar on the 380 Yeti and not on the 480 Yeti, I am all ears.

Re: Normal Diff Pinion Wear
 

i personally dont care about the torque twist, even if its on 3 Wheels when you floor it, its no big deal.
its not like if it was an on-road and in a race where it could make you loose 1/10 of a second per lap...

Re: Normal Diff Pinion Wear
 

So everyone that's replacing the diff gears. Are you putting new diff gear gaskets and o rings? Just ordered gears and noticed the gaskets after.

Re: Normal Diff Pinion Wear
 

I don't mind the torque twist either. Kinda adds to the beastly persona. And it's an easy upgrade. I don't think many rtrs include them. I do think it is an odd inconsistency between the yeti and xl, why include one and not the other.

Just to keep it on subject. My front diff is starting to pop under heavy braking. After I'd say 30 or so packs through it, and countless hard landings on the front end. I've got a steep brake curve and 100% brake power programmed in, shims installed. It has taken serious abuse, but I'm kind of disappointed to see the diff already failing.
The fact that the rear is solid and takes the brunt of the torque makes me think it's some design flaw in the front and not the gears themselves.

Re: Normal Diff Pinion Wear
 

My XL kit is having front diff issues as well. I ran it on 4s two times and now I have the Pop under heavy braking. I pulled the front end apart and there is wear on the outside of the bevel and in the middle of the pinion. It is clearly a mesh problem..

Anyone found a solution?

Re: Normal Diff Pinion Wear
 

I've gone through two front diffs now. Axial customer service sent me one and a purchased one. This last time I dry fitted everything with the bulkhead out of the RC. I did the diff first. I added shims inside the diff to take out play. I filled it with 100k fluid after that. I used Boca chromoly steel double rubber sealed bearings on the diff and fast eddy bearings in the pinion with solid aluminumin spacers between them (Dhawk on eBay) instead of that plastic piece. The diff has zero side to side play in the new bulkhead so I couldn't use shims behind the diff this time. All I can do is shim the pinion in and out. I got it all in and it spun freely with almost no play so we will see. I think...guessing...this thing is too damn heavy for the plastic front bulkhead and under flex the pinion goes way too deep into the ring gear and chews things up.
BUT...why are some people beating on their yeti XL and not having the front diff problem...how many are having it and are silent or don't post here. I may sell my xl before I use it again and just build something else. I don't want a rig I have to work on all summer. I do winter mods/rebuilds and changes. The warm weather is outside bash time.