Mojave Vitavon EXB 29mm Diff Cups

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They look sweet no doubt.
But, not using a Steel Insert where the Steel Input cup rotates/spins will ending up being a problem. 7075 alloy or 6061. I don't see any steel insert there....
Hot Racing tried that with their first design and they had to ultimately use a steel insert where the output cup spins. Many had issues with the HR alloy diff housing wearing out fast against the the steel output cup. Then bricking an otherwise good diff setup. @ $38. , they will have to be replaced often like HR's original design. Perhaps as often as a stock plastic diff housing. 🤷‍♂️ Steel will always wear out an alu metal. Steel output cups are much harder.
IDK about this Viviton Upgrade. I would pass.
Just my thoughts.
:cool:
 
Makes sense what you say.

Might be a better design using a seperate steel output plate on one side like the standard Arrma Aluminum diff cases? Guess we'll see what Arrma comes-out with as an upgrade to this chapter of Half-assery on Four Wheels...

Anyway, at least these won't be overstressing or cupping shims until a better solution is found. The plastic crap these come with is a last resort at this point with anything else being available for the job.
 
I wonder why she is only for the mojave exb 🤷 do they not fit in the kraton exb?
 
^^^ I questioned the exact same thing. 🤷‍♂️

I think that is incorrect information on the part of Vivaton. (n)

Because the EXB 29mm diff housing fits the stock plastic bulkheads, which was never changed for both the Mojave EXB and Kraton EXB.

EDIT: if I am correct, they both use the same beveled GP6 Input/Ring gears (F/R). 🤷‍♂️
:cool:
 
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I still say the Arrma metal diff housing is best. But I only use metal diffs at the center anyway. I heard they can be a bear to fit/shim correctly at the F/R's. And the they are fairly heavy IMHO.
 
They look sweet no doubt.
But, not using a Steel Insert where the Steel Input cup rotates/spins will ending up being a problem. 7075 alloy or 6061. I don't see any steel insert there....
Hot Racing tried that with their first design and they had to ultimately use a steel insert where the output cup spins. Many had issues with the HR alloy diff housing wearing out fast against the the steel output cup. Then bricking an otherwise good diff setup. @ $38. , they will have to be replaced often like HR's original design. Perhaps as often as a stock plastic diff housing. 🤷‍♂️ Steel will always wear out an alu metal. Steel output cups are much harder.
IDK about this Viviton Upgrade. I would pass.
Just my thoughts.
:cool:
Could you post a link to the HR diff cup with the steel insert? So far I've gone through two different aluminum cups that didn't have any steel inserts and I keep hearing about this infamous HR cup with a steel insert but have never seen one. The best I could find was the arrma diff cup that is part aluminum and part steel.
 
Hot Racing HRAAON11E02 (with steel insert)
Amain has it on Back Order.


Hot Racing Arrma 6S Aluminum Differential Carrier Case [HRAAON11E02] | Cars & Trucks - AMain Hobbies

>>>BUT, this is Not for the 29mm LSD GP 6 diffs/gears, and that is not what you are looking for. There are no EXB 29mm alloy cups from Arrma just yet. Haven't seen any from HR yet. Check HR's website. I just did.

Is there a reason why you need a 29mm alloy diff cup? The EXB composite diff cups are more robust than the prior 6S diff cups.. Never heard of any complaints yet. And lighter than any alloy would be. 🤷‍♂️ Rotating weight goes against you in any drivetrain, so if you don't absolutely need it, don't bother IMHO.
Vivaton is the only one I know of right now, it just doesn't seem like a good option without a Steel Insert for the rotating out drive on the one side.
HR tried that without a steel insert for the older 6s diff case/housing like I stated above and it was NG. So they re-made it in the above version With an insert.🤷‍♂️ If you choose any Alloy diff case wisely it's best that it has a Steel insert. Or pass on it.

Just my opinion and recommendation.

:cool:
 
Hot Racing HRAAON11E02 (with steel insert)
Amain has it on Back Order.


Hot Racing Arrma 6S Aluminum Differential Carrier Case [HRAAON11E02] | Cars & Trucks - AMain Hobbies

>>>BUT, this is Not for the 29mm LSD GP 6 diffs/gears, and that is not what you are looking for. There are no EXB 29mm alloy cups from Arrma just yet. Haven't seen any from HR yet. Check HR's website. I just did.

Is there a reason why you need a 29mm alloy diff cup? The EXB composite diff cups are more robust than the prior 6S diff cups.. Never heard of any complaints yet. And lighter than any alloy would be. 🤷‍♂️ Rotating weight goes against you in any drivetrain, so if you don't absolutely need it, don't bother IMHO.
Vivaton is the only one I know of right now, it just doesn't seem like a good option without a Steel Insert for the rotating out drive on the one side.
HR tried that without a steel insert for the older 6s diff case/housing like I stated above and it was NG. So they re-made it in the above version With an insert.🤷‍♂️ If you choose any Alloy diff case wisely it's best that it has a Steel insert. Or pass on it.

Just my opinion and recommendation.

:cool:
Nice ty for the part number. I have exb and non exb diffs. Haven't used the exb diffs yet
 
^^^Ok.
I wasn't sure what diffs you are using. I am not quick to jump into the LSD diffs. But they are more robust Input /ring gear wise IMHO, when they are setup good. They cost more also. 🤷‍♂️
I didnt want you to order the wrong stuff.
Honestly, I think the Arrma metal diff for the non EXB's at the Center is pretty robust. Albeit a bit heavier than the HR. I am not usually quick to buy all HR stuff. I've had bad luck with some of their stuff. And some are fine. Just that if you have any issues, HR is a Zero for Customer support. I have much of their HR Crawler stuff too and had many issues with fit on my Axial rigs. Arrma Upgrade option parts are usually dead on. And HH always picks up the phone.:LOL:
 
Blown-up diffs, worn cups... Blown-up diffs or worn cups... Such a tough choice.

I figure the risk of some possible wear on the cups from a bit of rotational torque is superior to having shims dish-out in an inferior plastic unit causing failure and ruining an outing. Wear is a given. The lateral forces on the input axis are nothing compared to the forces trying to hold a diff together in a plastic case that's dished on on one end. Well-shimmed diffs and bulkheads with nice bearings will further lessen those forces in my estimation. Not putting Arrma's plastic cups in Vitavon bulkheads, that's just wrong.

This isn't a philosophical or hypothetical discussion, it's going with the least risky and volitile setup hopefully and like much of what is done with these things (in Arrma's case as well apparently), it's trial and error.

Won't be trying to break my cars or dropping them out of the sky so I'm good. Replacing a cup here or there is no big deal and if it saves me some of the aggravation of Arrma's infamous grenading diffs, of which the new LSD diffs are an esteemed part whether anyone wants to admit it or not, then that's the purpose.

Hopefully Arrma is working-on their own version so we have more choices other than the plastic garbage that Arrma sells us in the box with their fancy LSD plates that they've had to offer 1.9mm washers to replace them because the existing setup works so flawlessly. /sarc
 
Blown-up diffs, worn cups... Blown-up diffs or worn cups... Such a tough choice.

I figure the risk of some possible wear on the cups from a bit of rotational torque is superior to having shims dish-out in an inferior plastic unit causing failure and ruining an outing. Wear is a given. The lateral forces on the input axis are nothing compared to the forces trying to hold a diff together in a plastic case that's dished on on one end. Well-shimmed diffs and bulkheads with nice bearings will further lessen those forces in my estimation. Not putting Arrma's plastic cups in Vitavon bulkheads, that's just wrong.

This isn't a philosophical or hypothetical discussion, it's going with the least risky and volitile setup hopefully and like much of what is done with these things (in Arrma's case as well apparently), it's trial and error.

Won't be trying to break my cars or dropping them out of the sky so I'm good. Replacing a cup here or there is no big deal and if it saves me some of the aggravation of Arrma's infamous grenading diffs, of which the new LSD diffs are an esteemed part whether anyone wants to admit it or not, then that's the purpose.

Hopefully Arrma is working-on their own version so we have more choices other than the plastic garbage that Arrma sells us in the box with their fancy LSD plates that they've had to offer 1.9mm washers to replace them because the existing setup works so flawlessly. /sarc
A worn out output diff cup, WILL ruin the sat and sun gears.
The EXB 29mm alloy carrier/cup are available now. FWIW.
 
I still say the Arrma metal diff housing is best. But I only use metal diffs at the center anyway. I heard they can be a bear to fit/shim correctly at the F/R's. And the they are fairly heavy IMHO.
For what it's worth I just weighed a fully assembled oem 6s center diff (non exb) against a fully assembled with the Arrma metal case and it is only 8 grams difference. 98 vs 106 grams. I also weighed an oem exb center diff at 111 grams.
 
Yeah that is roughly 10% weight. Doesn't seem like much. Add 10% to the rotating mass... well... lighter is better. I never had issues with the plastic diff case at the F/R. A plus to use the Metal case there for some better Durability, I surmise, if that is your objective. I only use the The Arrma metal case at the center. Where heat is more of an normal issue. If you have heat issues F/R, then you are doing something wrong, or it's merely a worn out diff overall. Time for normal service. Plastic standard diff cases are cheap and consumable parts IMHO. I change them out every 3rd rebuild or so as needed. The $23. Arrma metal diff's do wear out also. FWIW. And the stocker plastic case is $9. by comparison.
If running 8s gear ( 25% more power load), the 29mm EXB plastic case would be more benefitial. At roughly 13% more weight and rotating mass. I prefer open diffs all around. But EXB LSD diffs have more stout Main/Input gears. The main upsell in my opinion if you go LSD diffs.
I only run 6s, with the standard 6s RTR diffs. I feel they are more efficient at the F/R.
I try not to add weight to my rigs. Not that these are track rigs by any means. I just try to set them up that way. More nimble and break less. They become pigs with much of the upgrade alloy out there. Especially in my drivetrain. M2c chassis and braces, etc., are better trade offs for added weight.
HR diff alloy case is a bit lighter at the sacrifice of less durability. So I use the Arrma's metal ones.
I don't feel using upgrade alloy parts across the complete rig, replacing 90% of the OE parts is justified. Been there. Now I am more conservative using upgrade alloy in general.
Many feel different on this. We all drive our rigs differently and how we expect them to perform is all subjective.
Not trying to split hairs at all.
Thanks for posting the weights. Good info.(y):cool:
 
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