Kraton EXB diff problem

[Soilhalo77]

Hi need some quick help please guys
If I turn the rear wheels on my K EXB 6S both turn the same direction plus they also turn the fronts the same
Reverse it and turn the front wheels then they turn in opposite directions
So that means it’s the center diff where the problem is doesn’t it?
I had the front diff apart recently and noticed that the lsd parts had worn through use
Put it back together,all was good after straightening one of the lsd plates out but then started to heat a slight click every so often
So I’m planning on replacing the internals on all diffs but am I correct in thinking all wheels turn when I spin the rear wheels that it’s the center that’s the problem or is it possibly the rear too
Thanks I’m advance for any help
And Merry Christmas

 

[Engineer]

The way the front/rear wheels are turning depends on the viscosity of the fluid in the center diff. A light fluid will cause the F/R wheels to spin in different directions while a heavier fluid will act more like a locker/spool and cause everything to spin in the same direction.

I would just make sure the diffs are built properly and aren't locked up when you try to rotate the output cups in opposing directions out of the vehicle.

 

[HZRDOS]

If you hold one rear wheel, can you turn the other feeling some resistance? Or does it only turn together like a diff is locked up?

 

[Yas]

Sound like the rear diff internals to me!

 

[Soilhalo77]

If you hold one rear wheel, can you turn the other feeling some resistance? Or does it only turn together like a diff is locked up?

Like a diff is locking up but only when you aren’t holding other wheel

 

[Soilhalo77]

If you hold one rear wheel, can you turn the other feeling some resistance? Or does it only turn together like a diff is locked up?

Yes the rear does plus turn 1 rear and it turns all 4 wheels
Turn 1 front wheel and everything is normal

 

[HZRDOS]

OK. I am really trying to follow what is happening.

So - if just lift the rear up, leaving front on ground - turn one rear wheel. If the other turns (same direction or opposite), that is good. If it turned in same direction, lift the front tire off the ground and hold one rear and turn the other. If it turns while the other rear does not, and also turns front wheels - then rear should be fine.

Do the same exercise for the front.

Now place rear on the ground, hold both fronts still, and drag the rears on the ground. If the rears turn while holding the fronts (with some resistance) then the center diff is good.

Does it drive fine? Any issues when running?
Remember - this is not a full open with no internal diff resistance. Depending on the diff fluid viscosity, there it takes more force to spin the wheels at different speeds/directions when testing off the ground. None of mine will free spin in opposite directions unless you hold the center diff and not let it turn.

 

[Soilhalo77]

OK. I am really trying to follow what is happening.

So - if just lift the rear up, leaving front on ground - turn one rear wheel. If the other turns (same direction or opposite), that is good. If it turned in same direction, lift the front tire off the ground and hold one rear and turn the other. If it turns while the other rear does not, and also turns front wheels - then rear should be fine.

Do the same exercise for the front.

Now place rear on the ground, hold both fronts still, and drag the rears on the ground. If the rears turn while holding the fronts (with some resistance) then the center diff is good.

Does it drive fine? Any issues when running?
Remember - this is not a full open with no internal diff resistance. Depending on the diff fluid viscosity, there it takes more force to spin the wheels at different speeds/directions when testing off the ground. None of mine will free spin in opposite directions unless you hold the center diff and not let it turn.

Ok sorry if I’m not explaining it very well
Start with all 4 wheels off the ground ok
Turn the front one way and opposite front turns the other way. As it should be
Turn one of the rears and all 4 spin same direction
Last time I used it I heard a slight clicking noise but intermittently
This all happened when I was away camping and I first had to swap out the front diff for a new one and I noticed that the lsd plate had slid under the gasket slightly and one of the plates was warped a little so I straightened it out turned the gasket over and everything seemed fine
It was a temp fix until I got home but a few sessions after fixing it while still away I started hearing the clicking noise but at that point when you turned the diffs with wheels off the ground all was good.
Still with me?
Now I’m home and I’ve not yet dived in to the diffs but turn the rears (1hand on each wheel) and turn them in opposite directions and there’s a binding of some sort then in turns freely and then after a few turns binds again or gets tight rather. That would explain the clicking I could hear

 

[HZRDOS]

Ok. Rear diff internals is the issue. I would guess a tooth or two on the sun gear is gone.

 

[Soilhalo77]

Ok. Rear diff internals is the issue. I would guess a tooth or two on the sun gear is gone.

Yeah I was guessing the same
Hopefully I’ll get it apart this weekend and get all the new stuff ordered
Tbh all the diffs need a service, they’ve ran for a year without changing anything and I run high gearing on my HW 1650kv. 23/50 so there’s a lot of power going through
Thanks for the advice and merry xmas

 

[HZRDOS]

Yeah I was guessing the same
Hopefully I’ll get it apart this weekend and get all the new stuff ordered
Tbh all the diffs need a service, they’ve ran for a year without changing anything and I run high gearing on my HW 1650kv. 23/50 so there’s a lot of power going through
Thanks for the advice and merry xmas

Nice. I run the exact same on my Kraton and OC. Same motor and gearing. They are CRAZY fast bashers!

 

[VDVC-RC]

TLDR:
JUST BASH IT! BUT UPGRADE TO ALUMINUM 29mm Diff housings & rebuild with new LSD plates.

I had a similar issue with the EXB center diff I put in my Typhon.
My bearing went in my front diff causing it to lose contact with the input gear.
Figuring the EXB diff could take it, I just removed the front driveshaft to see if it would drive...
BIG MISTAKE!
The EXB center diff overheated, blew the seal, warped the LSD plates & I think melted the plastic diff housing a lil inside where the plates rest.

After rebuilding it & replacing the front diff bearing, I now had a 1.5 way center diff.
Front driveshaft practically locked like a spool @ all speeds if I turn the front wheels together by hand.

If I turn the rear wheels I got normal center diff action by hand.
Drove like a dream for a while with 10k diff fluid in it and eventually as the plates wore it returned to normal operation. But I ordered an aluminum 29mm case just to be safe... I don't trust the ARRMA seals & plastics in my drivetrain.
I bash too hard!