Mojave Crunchy Moj EXB Diffs

[Grimbles]

TLDR: did I cook my diff? Other than v black oil and a bit of scoring on the diff case, can't work out why the diff went so crunchy, I couldn't spin the wheels.

Righto brains trust, here's a puzzler! Me and my buddy @Glenn75 were out on Sunday, great new bash spot. Big open field where some dirt bikers have worn out a dirt track. Bit of crud on the field which bound up a driveshaft on my typhon 3s enough to make it pop a driveshaft, but otherwise a lot of fun and powerslides especially with the moj. Moj has probs had 10 6s packs through it total.

I got home and the rear wheels on the moj were grinding/binding when I twisted them with my hand. So much so they stop spinning and start turning the motor. Feel crunchy.

I stripped down the diff. There was a definite smell of burning to the diff oil which came out and it was very black. Most I've ever seen probs 3/4 full still though. No damage at all to the gubbins in the diff - all teeth on all gears present and correct, no evidence of issues EXCEPT the inside of the diff case looks a bit scored. Was running stock (10k) oil and minimum effect slip configuration. Front diff is still buttery!

So, brains trust, What do we think - did I cook it? Have ordered a new diff case (good to have a spare anyway).

@BashingBrian @Sandracer_NL @jondilly1974 @L3phturn @FatCatRC and anyone else who wants to chip in!

 

[K-BASH]

I've seen centers get upto 180,u musta had it glowing, mmx & tp will do it

 

[Grimbles]

I've seen centers get upto 180,u musta had it glowing, mmx & tp will do it

Funny thing is, this was the rear. I was just having a great time doing powerslides lmao. I figured I had cooked it :/ I think heavier diff fluid is probably the answer then...

 

[jondilly1974]

TLDR: did I cook my diff? Other than v black oil and a bit of scoring on the diff case, can't work out why the diff went so crunchy, I couldn't spin the wheels.

Righto brains trust, here's a puzzler! Me and my buddy @Glenn75 were out on Sunday, great new bash spot. Big open field where some dirt bikers have worn out a dirt track. Bit of crud on the field which bound up a driveshaft on my typhon 3s enough to make it pop a driveshaft, but otherwise a lot of fun and powerslides especially with the moj. Moj has probs had 10 6s packs through it total.

I got home and the rear wheels on the moj were grinding/binding when I twisted them with my hand. So much so they stop spinning and start turning the motor. Feel crunchy.

I stripped down the diff. There was a definite smell of burning to the diff oil which came out and it was very black. Most I've ever seen probs 3/4 full still though. No damage at all to the gubbins in the diff - all teeth on all gears present and correct, no evidence of issues EXCEPT the inside of the diff case looks a bit scored. Was running stock (10k) oil and minimum effect slip configuration. Front diff is still buttery!

So, brains trust, What do we think - did I cook it? Have ordered a new diff case (good to have a spare anyway).

@BashingBrian @Sandracer_NL @jondilly1974 @L3phturn @FatCatRC and anyone else who wants to chip in!

View attachment 135675

My best guess is you were making those LSD plates work and that created heat, which cooked the case and fluid. Might try some shims instead of plates with some 20k and see how that rolls.

 

[Grimbles]

My best guess is you were making those LSD plates work and that created heat, which cooked the case and fluid. Might try some shims instead of plates with some 20k and see how that rolls.

Cheers chap, might give this a go

 

[Jon NC RC]

If it has a definite burnt smell , it is.....sounds like Dr Dilly has a good prescription

 

[BashingBrian]

My best guess is you were making those LSD plates work and that created heat, which cooked the case and fluid.

What he said..

May want to rebuild fully open with 20k

 

[Grimbles]

My best guess is you were making those LSD plates work and that created heat, which cooked the case and fluid. Might try some shims instead of plates with some 20k and see how that rolls.

What he said..

May want to rebuild fully open with 20k

Is ARA311094 the shim set you guys have used?

 

[BashingBrian]

I do my own homebrew version ( see my build thread ), but yes those ones you posted will work

 

[jondilly1974]

Is ARA311094 the shim set you guys have used?

I own that set but haven’t needed them yet. I am still using the ones from McMaster Carr that @Rcproponent sent me last year. He sent me enough for 50 diffs

 

[Jon NC RC]

Is ARA311094 the shim set you guys have used?

Grimbles.....you can call yourself the certified unintentional diff destroyer!!!!

Just give it time, I'll shred one of mine.....at least you had fun doing it !!! Nice to find a place like you described.....

 

[Rcproponent]

I own that set but haven’t needed them yet. I am still using the ones from McMaster Carr that @Rcproponent sent me last year. He sent me enough for 50 diffs

I was just planning ahead

 

[Sandracer_NL]

+1 on what @jondilly1974 said. Yes Ara311094 is for the EXB. D@mn my Mugen Seiki E0206 spare diff shims won’t fit the Mojave EXB I see . Expecting the MEXB tomorrow, can’t wait!

 

[Grimbles]

+1 on what @jondilly1974 said. Yes Ara311094 is for the EXB. D@mn my Mugen Seiki E0206 spare diff shims won’t fit the Mojave EXB I see . Expecting the MEXB tomorrow, can’t wait!

Exciting times. Build thread and pics please

 

[Sandracer_NL]

@Grimbles
you said it’s only the rear diff. Do you know if your Mojave has the open rear diff or the ’newer version’ LSD diff?
The manual says that front and center diff are set to max LSD effect and rear diff is open. The ‘new’ exploded view of the MEXB of Armma site shows front and rear diff with max LSD effect and rear diff with minimum LSD effect.
If you have the rear open diff and want the newer LSD rear diff Ara311094 won’t do it.

 

[Grimbles]

@Grimbles
you said it’s only the rear diff. Do you know if you have your Mojave has the open rear diff or the ’newer version’ LSD diff?
The manual says that front and center diff are set to max LSD effect and rear diff is open. The ‘new’ exploded view of the MEXB of Armma site shows front and rear diff with max LSD effect and rear diff with minimum LSD effect.
If you have the rear open diff and want the newer LSD rear diff Ara311094 won’t do it.

I asked this question in my build thread and posted some manual comparisons. My manual says rear diff comes open, website says lsd to minimum effect. I received lsd to max effect in all 3 diffs lol. Obvs rebuilt as priority before my first pack went through her.

So I'm going lsd-> open

I asked this question in my build thread and posted some manual comparisons. My manual says rear diff comes open, website says lsd to minimum effect. I received lsd to max effect in all 3 diffs lol. Obvs rebuilt as priority before my first pack went through her.

So I'm going lsd-> open

EDIT: I tell a lie, I started a thread on this! https://www.arrmaforum.com/threads/exb-differentials-different-difficulties-diffeated.29646/
Tell you what though, when those 29mm metal diff cases make it to the UK will be purchasing me a few of those

 

[L3phturn]

I asked this question in my build thread and posted some manual comparisons. My manual says rear diff comes open, website says lsd to minimum effect. I received lsd to max effect in all 3 diffs lol. Obvs rebuilt as priority before my first pack went through her.

So I'm going lsd-> open

EDIT: I tell a lie, I started a thread on this! https://www.arrmaforum.com/threads/exb-differentials-different-difficulties-diffeated.29646/
Tell you what though, when those 29mm metal diff cases make it to the UK will be purchasing me a few of those

I"m curious if you rebuilt the rear with minimum LSD and with the correct plate orientation?

I am running 7,000 weight fluid and minimal LSD in the rear of the boy's Kraton EXB and have not had a problem yet. I ran it quite a bit on snow and ice, which certainly exercised the diffs when one wheel had traction and another was on pure ice. I'll keep an eye on it. I don't yet know if I want to rebuild open in the rear because his Ecoboost got water in it and fried so I have the 15kg stock servo from my Notorious V4 in his EXB for now - so the thing doesn't turn for crap.

 

[Grimbles]

I'm curious if you rebuilt the rear with minimum LSD and with the correct plate orientation?

Very much yes. On another diffs thread @jondilly1974 had specifically flagged this and I had stripped down and re-re-assembled that diff as a result! I can say with absolute certainty it was 10k diff oil in a minimum effect configured lsd diff that was properly assembled and buttery smooth when it went in

 

[BashingBrian]

I forgot to ask, were you on 6s or 8s ???

 

[Grimbles]

I forgot to ask, were you on 6s or 8s ???

6s. Haven't dared with 8s yet!