Kraton Hot racing diff cases

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Terrance

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Arrma RC's
  1. Kraton 6s
May be a silly question but what is the difference between the hot racing diff cases for the kraton 6s? There are the (Reg) ones then the (Modular) ones?
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Some have said one type fits better within the diff bulkheads. The other fits better in the center. IDK what's actually true in regard. I only use the Arrma metal variant for my center diff. I keep the stock plastic for my Fr and Rr diffs. right now.

>>>I will say that HR had made the original one out of alloy completely at one end, this caused one output cup to wear it out excessively fast. NG.
There was a newer HR one with a Steel Insert in place on the Alloy end now, that doesn't wear out. Perhaps you are seeing an old and newer released one.
Make sure to get the one with the Steel Insert for obvious reasons cited above. If that distinction is clear enough as described by the seller and according to its part number. Go to HR's web site to confirm the correct revised version.
Hopefully others will chime in.
:cool:
 
Some have said one type fits better within the diff bulkheads. The other fits better in the center. IDK what's actually true in regard. I only use the Arrma metal variant for my center diff. I keep the stock plastic for my Fr and Rr diffs. right now.

>>>I will say that HR had made the original one out of alloy completely at one end, this caused one output cup to wear it out excessively fast. NG.
There was a newer HR one with a Steel Insert in place on the Alloy end now, that doesn't wear out. Perhaps you are seeing an old and newer released one.
Make sure to get the one with the Steel Insert for obvious reasons cited above. If that distinction is clear enough as described by the seller and according to its part number. Go to HR's web site to confirm the correct revised version.
Hopefully others will chime in.
:cool:
Yeah, the arrma one uses a steel end cap. Fitment can be a bit problematic though...
https://www.arrmaforum.com/threads/issue-with-the-arrma-alloy-diff-cup-seems-too-long.14517/

After fighting with the arrma 2 piece cups fitment last year, I haven't had ring/pinion failure this year, thank god. I did break one sun gear (larger gear inside the diff) this year. The pin under it also broke. Not sure if one caused the other, but either way that was the first one to do that since I got the truck in 2018. Before the alloy cups, I went through 6 diff ring/pinions. All shimmed properly/as tight as I was comfortable with. One died due to bearing failure, another died due to stripped diff cap/bulkhead screws, the other 4... no clue. So it seems the alloy cups add some needed rigidity to the ring gear since I haven't had a failure with the ring/pinion since I figured out how to get them fit with proper gear lash (which is documented in that thread).
 
The second is the old version and from what I gather its a leaker. I have (2) of the first in center and rear. The gears fit good inside good inside the ones I have.
 
Has anyone had dramas getting the drive cups out before?
There was no obvious defect on the shaft or steel housing on the diffcup.











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I had to sand mine down inside the cup when the pin and sun gear shattered. It mushroomed the output shafts hole where the pin went and I couldn't get it out. Was a pain sanding that with my dremel down inside the cup enough so I could work it out without really damaging the cup.
 
May be a silly question but what is the difference between the hot racing diff cases for the kraton 6s? There are the (Reg) ones then the (Modular) ones?View attachment 113634View attachment 113635
I've used both, I like the one piece better because that o-ring on the two piece tends to leak. Also, you must put a shim behind the sun gear because the pin will eat into the case.
 
^^^ Thats why I like the Arrma metal version. I would use them in the center only. I'm just trying to keep my front and rear diffs lighter with stock plastic. I run only stock electrics. If I were to run 8S stuff I may have to use Metal diffs fr and Rr. ?‍♂️ I feel the HR 's are flawed and are no better than stock just from what others have stated. My Arrma metal diff in the center (w/500k CST) has been the most durable of all for me. Never blew it out. It has outlived my fronts and rears twice over so far. And the original build is still going. I also have a spare assembled metal center diff for my other rigs. Which ever blows out first will get that one. I have also heard that if you are using a HR bulkhead along with the Arrma metal diff, it can be problematic with the fit. That there is a slight rubbing. I don't use HR bulkheads right now. They appear beneficial in an 8S setup. Probably better with the plastic stock diffs.?‍♂️ IDK. The HR Bulkheads are costly. Some say more important at the rear. Leaving a plastic Bulk head in the front is fine.

Edit:
The HR modular Diff with 2 piece setup, o-ring has been known to leak. But probably the best of the 2 HR's. It wont wear out, like the other original design. The key is to use a silicone gasket adhesive along the o-rings and and they stay sealed. That's one fix I've seen. I rather have the Arrma variant. It works for me, so I wont chance HR one. Yet most guys are using HR from what I see. The Arrma version IS heavier. FWIW.
 
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