Mojave Mojave exb diff issues

[joebryant1224]

Need help have the Mojave exb and having front diff issues and kind of just getting in the hobby. It’s like the front is locking up sometimes just need a parts number to fix the issue.

 

[L3phturn]

Need help have the Mojave exb and having front diff issues and kind of just getting in the hobby. It’s like the front is locking up sometimes just need a parts number to fix the issue.

Step one - describe the issue.
Step two - take it apart.

 

[Cheez]

And pictures

 

[joebryant1224]

Step one - describe the issue.
Step two - take it apart.

The front wheels will sometimes lock and then sometimes they will be open like they should be. New to the forum I will try and get it apart tomorrow for better details also trying to make it some what built proof if there is such a thing.

 

[Engineer]

Have you previously serviced the diff or is this happening "as it comes" from the factory?

 

[joebryant1224]

Have you previously serviced the diff or is this happening "as it comes" from the factory?

It’s new it’s only had 3 packs run through it.

And pictures

So the gear with the yellow circle is missing parts of the teeth, explains the reason for lock-in up at times. So is there away to maybe bullet proof the front center and rear diffs

 

[L3phturn]

You seem to be missing a piece. There should be another star plate.

 

[joebryant1224]

Have you previously serviced the diff or is this happening "as it comes" from the factory?

It’s new it’s only had 3 packs run through it.

And pictures

View attachment 120516

 

[Engineer]

You seem to be missing a piece. There should be another star plate.

My observations as well from the pictures. If that was the case, hit up Horizon for the warranty and have them send you new gears and plates.

 

[jondilly1974]

Same issue all of us had with the rear EXB diffs, broken sun gears. What shims are under the pins of the output shafts?

 

[L3phturn]

Same issue all of us had with the rear EXB diffs, broken sun gears. What shims are under the pins of the output shafts?

That’s an LSD diff so the problem is he is missing one of the star plates. That is equivalent to missing a lot of shim behind the sun gear, so if he really only had one star plate in there it would absolutely fail, and fast.

 

[IrieWheeler]

Vitavon just listed their 29mm diff cups too and I bet they're not concave on one end...

 

[Lushious Larry]

Mine didn't last much longer on my exb. Arrma needs to go back to the drawing board on these diffs.they are garbage in my opinion. Got my truck up and running two weeks ago and had to build both diffs already and hard to find parts for right now.

 

[L3phturn]

Mine didn't last much longer on my exb. Arrma needs to go back to the drawing board on these diffs.they are garbage in my opinion. Got my truck up and running two weeks ago and had to build both diffs already and hard to find parts for right now.

Properly built and shimmed the 29mm are the strongest 6S diffs they have ever built. Looks like a combination of assembly errors and people being super hard on them to me. Most people I know with a recent EXB have not had an issue.
Including my son.

 

[Lushious Larry]

Properly built and shimmed the 29mm are the strongest 6S diffs they have ever built. Looks like a combination of assembly errors and people being super hard on them to me. Most people I know with a recent EXB have not had an issue.
Including my son.

I've tried shimming them a few times and yes I beat them hard but all my drag builds are beat alot harder and only busted a couple old style gears. Plus parts are hard to find right now and the last thing I want is to push a 1000 dollar arrma around because it has no diffs in it.

 

[jondilly1974]

I've tried shimming them a few times and yes I beat them hard but all my drag builds are beat alot harder and only busted a couple old style gears. Plus parts are hard to find right now and the last thing I want is to push a 1000 dollar arrma around because it has no diffs in it.

What shims are you using? I ask because there are a lot of ways people have shimmed in the past.

 

[Lushious Larry]

What shims are you using? I ask because there are a lot of ways people have shimmed in the past.

13x16x2 behind spider with and without lsd plates.to much play in spider gears from factory are only just meshing from what I can tell. With lsd added 2 .02 shims to each side and ain't had no issues yet with front diff and removed lsd plates from rear all together.

 

[jondilly1974]

13x16x2 behind spider with and without lsd plates.to much play in spider gears from factory are only just meshing from what I can tell. With lsd added 2 .02 shims to each side and ain't had no issues yet with front diff and removed lsd plates from rear all together.

You should get the 12x18 shims instead of the 13x16. They support the sun gear perfectly. Arrma sells them now.

 

[Lushious Larry]

You should get the 12x18 shims instead of the 13x16. They support the sun gear perfectly. Arrma sells them now.

View attachment 120575

Thanks for the info my friend i will get some coming.

 

[Engineer]

You should get the 12x18 shims instead of the 13x16. They support the sun gear perfectly. Arrma sells them now.

definitely go with12x18 shims. I’m trying a hybrid right now with some of the active plates and McMaster 12x18 shims to support the ridges on the backside of the sun gear which the factory 12x18x1.9 shims do not: