Kraton Diff gears stripping, help!

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Jim28

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Arrma RC's
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Hi, i'm on my like 3rd set of front differential gears and housing. i've been i the hobby 25 years, i like to think i know what i'm doing. everything else on the truck is ok. there's no binding, the mesh is ok, i changed diff fluids to thinner to hopefully protect the gears a little more, the housings looked fine, ad i'm about to chage the esc punch cotrol to lower (i think this'll solve my problem). has anyone else had this happen? how did you stop it? i do run it hard and on pavement lot but i rarely jump it or run into things. thanks.
 
Hi, i'm on my like 3rd set of front differential gears and housing. i've been i the hobby 25 years, i like to think i know what i'm doing. everything else on the truck is ok. there's no binding, the mesh is ok, i changed diff fluids to thinner to hopefully protect the gears a little more, the housings looked fine, ad i'm about to chage the esc punch cotrol to lower (i think this'll solve my problem). has anyone else had this happen? how did you stop it? i do run it hard and on pavement lot but i rarely jump it or run into things. thanks.
which kraton is it
 
Hi, i'm on my like 3rd set of front differential gears and housing. i've been i the hobby 25 years, i like to think i know what i'm doing. everything else on the truck is ok. there's no binding, the mesh is ok, i changed diff fluids to thinner to hopefully protect the gears a little more, the housings looked fine, ad i'm about to chage the esc punch cotrol to lower (i think this'll solve my problem). has anyone else had this happen? how did you stop it? i do run it hard and on pavement lot but i rarely jump it or run into things. thanks.

I'm certainly no vet. Front diffs I do not have issues with more of the rear me. Shimming has been king for me. It took me a while to get the right touch and have the right size shims on hand.

I never had this on a 6S, but on my 8S, diff housing flexing, so I went to an aluminum diff.

Could be a plastic diff housing
 
I'm certainly no vet. Front diffs I do not have issues with more of the rear me. Shimming has been king for me. It took me a while to get the right touch and have the right size shims on hand.

I never had this on a 6S, but on my 8S, diff housing flexing, so I went to an aluminum diff.

Could be a plastic diff housing
You think the aluminum box helps? how did you know your housing was flexing?
 
If its the front specifically, the problem isn't power or punch.
It's excess friction/binding somewhere. If the mesh is shimmed properly, then it must be somewhere in the front axles. Check through the full range of suspension and turn angle for any binding.
If its the 4s version, there are different pitch sizes or teeth length, not positive for the ring/pinion. They mesh well enough to assemble but not well enough to work. They were composite from older 2s/3s rigs, but wouldn't be surprised if the 4s metal ones had the same problem. This likely isn't the case, but worth keeping in mind since it's burned me in the past.
Worth checking ALL the bearings, from the diff input right to the wheel hubs.
 
Is it stock electronics? Is the brake set too high? A high brake setting is tough on the center diff but can take out a front.
 
I've never had any luck with 31mm BLX diffs. I recommend switching to 29mm EXB diff cases and the gears that go with them. As far as aluminum diff cases and gearboxes are concerned I would run the EXB diffs for a few runs and see how they perform first.
 
Plastic components with metal inserts have a short life on 6S. Proper tooth mesh needs to be set with the gearbox off the chassis, shim until slightly binding and remove input/crown gear bearing shims as needed to create minimal play without interference.
 
Plastic components with metal inserts have a short life on 6S. Proper tooth mesh needs to be set with the gearbox off the chassis, shim until slightly binding and remove input/crown gear bearing shims as needed to create minimal play without interference.
will exb gearboxes work on a v4?
 
will exb gearboxes work on a v4?
Bulkheads are the same(universal), just make sure the ring/crown and input are same tooth count/spiral cut and intended for the same diameter diff carrier(29mm-EXB vs 31mm-BLX).
 
You used thinner diff oil? That is a bad idea, you should go a lot higher.
Usual mix is 50k front, 100k center and 30k rear.
30/100/30 is not uncommon either but really depends on your style. I have never heard of anyone going lower than stock ( think it's 7/20/7 but don't quote me on that, it's in the manual anyway)
At lower k values your gears are working overtime and you will wear them out, plus the handling is miserable imho.
 
so if i buy a complete exb gearbox it'll fit? like thee outdrives are compatible with v4 axles right? i'lll probably try them next
 
You used thinner diff oil? That is a bad idea, you should go a lot higher.
Usual mix is 50k front, 100k center and 30k rear.
30/100/30 is not uncommon either but really depends on your style. I have never heard of anyone going lower than stock ( think it's 7/20/7 but don't quote me on that, it's in the manual anyway)
At lower k values your gears are working overtime and you will wear them out, plus the handling is miserable imho.
i was under the impression thicker fluid has less shock absorbing action than thinner, is this right?
 
If you're running a motor the size of a beer can, thinning out your center diff so some of that power can be pushed forward will save your rear diff. With a stock 2050kv motor your diffs shouldn't have any problems. My XL has a stock 2050kv motor and I run 1000k in the center, I have no diff issues.

If you're looking into getting whole filled gearboxes I recommend Big Rock gearboxes from Jenny's. They're 29mm diff cases and gears except they'll be assembled open (without LSD plates). I have them on both my Outcast and my XL Kraton.
 
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You think the aluminum box helps? how did you know your housing was flexing?
As one user poster, it could have a small fracture. You have some excellent feedback. I've never owned the v4 model. My first Kraton was the first EXB version.
 
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