Kraton HR EXB 29mm Diff Case

[HZRDOS]

Hot Racing has an aluminum diff case for the EXB diffs now. Wanted to wait for the Arrma one that is about to be released....thoughts on the HR one versus Arrma?

https://hot-racing.com/?partnumber=AON11ETN02;c=926

 

[Rcproponent]

I know the non exb hr cases of that design are junk. And finding those o/rings that are proprietary to that case is hard.

just to clarify I wasn’t saying HR was junk just this piece… people were having issues with them leaking and stuff.

 

[HZRDOS]

I know the non exb hr cases of that design are junk. And finding those o/rings that are proprietary to that case is hard.

just to clarify I wasn’t saying HR was junk just this piece… people were having issues with them leaking and stuff.

Thanks. My buddy has the HR diffs on his 4s, and they are trash. Fitment issues, etc. I LOVE the Arrma aluminum cases on my standard 6s diffs - have all 3 on my Typhon done. I think I will wait for the Arrma ones. Will be time to redo/check the diffs in a month or so at that time anyways.
And yeah - I love the HR hubs and aluminum center diff mount! Also the bulkheads are good stuff.

 

[JvG]

The Arrma one that is about to be released?
I always miss these….

 

[KevinC]

September I think….

 

[BashingBrian]

The Arrma one that is about to be released?
I always miss these….

Arrma 29mm diff case... when, where, how..
What I want is a 46T or 52T spur for the EXB center diff case..!!

 

[JvG]

Arrma 29mm diff case... when, where, how..
What I want is a 46T or 52T spur for the EXB center diff case..!!

It’s about to be released the coming years

 

[Engineer]

What I want is a 46T or 52T spur for the EXB center diff case..!!

Right when the EXtreme Bash Felony shows up…

 

[HZRDOS]

Arrma 29mm diff case... when, where, how..
What I want is a 46T or 52T spur for the EXB center diff case..!!

https://www.horizonhobby.com/product/metal-diff-case-29mm/ARA311061.html

 

[JvG]

https://www.horizonhobby.com/product/metal-diff-case-29mm/ARA311061.html


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Subscribed!
As i said i always miss these updates, thanks, glad we have this forum!

 

[HZRDOS]

Update...DO NOT GET THIS POS PART! It will not work for the center diff. The end of the case sits too close to the mount due to the lack of a ridge to raise where the bearing sits and to create clearance between the center diff mount and the case.

Here is the issue. Notice next to a stock case - the bearing on the stock case is raised up on a ridge to keep clearance between the mount and the case end

HR end:

Here is the new design of the Vitavon case - notice the raised area to create the clearance

This is what happened:

 

[HZRDOS]

I contacted HR, and they are sending me a new case. Really don't know if I want it. I MAY try it in a front/rear diff and look at the clearances really well before trying.

 

[L3phturn]

I have not had any issues with the plastic diff cup. Aluminum diff housing and cover makes sense as most diff issues I’ve seen are ring and pinion from the diff shifting in the housing.

 

[HZRDOS]

I have not had any issues with the plastic diff cup. Aluminum diff housing and cover makes sense as most diff issues I’ve seen are ring and pinion from the diff shifting in the housing.

Issue is the screws on the plastic will come a bit loose and sling the fluid out after it gets hot.

Also after a diff rebuild, the tops of the holes where the screws go will sometimes raise up a little from tightening them, which will create a not perfectly flat surface for the spur to mount to, which can contribute to the leak of fluid.

Also - trying to add an extra shim to the bottom of the plastic case and shove the pin though the outdrive hole through the little hole in the side of the case just sucks. Sometimes not possible to add a third shim if needed. I like the cases that come fully apart with the end that comes off for this reason.

I did happen to find that Vitavon now makes this for the 29mm diff. I ordered a few of them (since the Arrma ones still are not shipping and listed on preorder/backorder

https://www.ebay.com/itm/284574430025

 

[Greengaunja]

Update...DO NOT GET THIS POS PART! It will not work for the center diff. The end of the case sits too close to the mount due to the lack of a ridge to raise where the bearing sits and to create clearance between the center diff mount and the case.

Here is the issue. Notice next to a stock case - the bearing on the stock case is raised up on a ridge to keep clearance between the mount and the case end

View attachment 189313


HR end:
View attachment 189307

View attachment 189308


Here is the new design of the Vitavon case - notice the raised area to create the clearance

View attachment 189309

View attachment 189310
View attachment 189311

View attachment 189312

Hmmm.. I run this in all three diffs and have no issue with the center. I wonder if possibly it's because they designed it to work with the HR motor mount and center support, both of which I also use.

 

[HZRDOS]

Hmmm.. I run this in all three diffs and have no issue with the center. I wonder if possibly it's because they designed it to work with the HR motor mount and center support, both of which I also use.
View attachment 189325View attachment 189326

Yours does not say 29mm diff case? Is it for the EXB diffs with LSD plates? The 29mm diff?
Noticed yours does have a raised portion to give it clearance:

 

[Greengaunja]

Yours does not say 29mm diff case? Is it for the EXB diffs with LSD plates? The 29mm diff?

I'm not sure. Just looks the same. If this isn't the same case, disregard what I said. All I know is it's for 1/8 Arrmas.
No it isn't. Good call.

 

[21STalion]

I have a EXB and replaced all three with HR and they all fit perfectly, really don't know what went wrong with the others here.

 

[slick2500]

I have a EXB and replaced all three with HR and they all fit perfectly, really don't know what went wrong with the others here.

Tolerances in manufacturing. Even in 1:1 cars you seriously can find things off by a few inches from one car to another. For instance, back when I was on a car forum a lot of guys would put headers on their car, some guys the headers would hit the radiator fan in the front some cars the rear O2 sensor would hit the firewall and some cars they would fit like a glove, my 97 they hit the fans my 01 the O2 sensor hit the firewall.

 

[HZRDOS]

I have a EXB and replaced all three with HR and they all fit perfectly, really don't know what went wrong with the others here.

Issue in the case I had was the spacing between the bearing and case face. End of case rubbed the diff mount.

Maybe it was just a new design where they screwed up? In this pic from @Greengaunja - you can clearly see the extra raised portion mine didnt have.