Senton 6s diff O-rings?

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JPWSRC

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Arrma RC's
  1. BigRock 4x4
  2. Kraton 8S
  3. Kraton 4s
  4. Nero
  5. Outcast 6s
  6. Outcast 4s
  7. Typhon 3s
Been going through the diffs on my V3 Senton. Was gonna replace the O-rings given its age and use. I wasn't aware there was a revision to these damn things? I picked these up at the LHS based on what the manual specified but for the life of me I can't get these damn O-rings to seat in the recess. I can put the originals back in, but these replacements wont go in! Clearly the new ones are much thicker.
Also,
I don't know why there's no washer/shim behind the planetary gears in these diffs so I decided to hold off and ordered a Mugen shim kit so I can install a shim under the planetary gears. I'm hoping that will be enough to seal off the output shafts and prevent wear in the diff cup and ring gear internal face.
Are the OE output shaft pins adequate, or do I need to find/make longer ones?
Sorry if this has been asked before... I've been searching for the last few days and no video tutorial lists what O-rings they're using because they are all reinstalling the ones that were there already. A few videos mention the planetary shims and custom pins made from a drill bit shaft.
I'd appreciate any direction yall can provide.
My LHS is useless.

20220406_133411.jpg


20220406_133436.jpg
 
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There is aways a shim under the large Sun gears! Or the O-Ring wont be sealing well at all. Shim must sit flat against the O-ring and capture it. Not sure what you mean by there are NO shims under your gears.:unsure: Mugen shims are best as you know. Made of spring steel.
Those O-rings pictured are absolutely Incorrect. Wrong size, too large. (n)Could be for 8s Diffs. or EXB 29mm diffs? Pretty sure they are? Double check the Part number. Could even have been Mis-packaged from Arrma. Has happened before with many small parts. Wouldn't be the first time. Perhaps the LHS was looking at the wrong rig??? Very possible. I would return them. Not a fit at all. Can't put a square into a hole.:giggle: Have replaced o-rings with new many times. No revisions that I know of. Same size, never changed. (RTR 6s "Open" diffs)
O-rings can be reused in most cases. Unless they are very obviuously worn or clearly damaged.
I always use a silicone grease on the o-rings. Some just use some diff oil. Fine enough. Some will use shock o-ring lubes. Like TA's Green Slime if you have that on hand. Lubing the o-rings, they will last longer. Less chance for diff oil leakage at the outdrives. Remember that the Outdrives spin rather fast inside of these o-rings. Equates to much friction on the o-rings. How and why they normally would wear, for this reason. Also a good idea to always use grease on the outdrive shaft before inserting into the diff cup. Tekno does this with their diffs. I always do it. Any diff. Outdrives and diff cups and main gears will last longer.
My spin.:cool:

edited.
 
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There is aways a shim under the large Sun gears! Or the O-Ring wont be sealing well at all. Shim must sit flat against the O-ring and capture it. Not sure what you mean by there are NO shims under your gears.:unsure: Mugen shims are best as you know. Made of spring steel.
Those O-rings pictured are absolutely Incorrect. Wrong size, too large. (n)Could be for 8s Diffs. or EXB 29mm diffs? Pretty sure they are? Double check the Part number. Could even have been Mis-packaged from Arrma. Has happened before with many small parts. Wouldn't be the first time. Perhaps the LHS was looking at the wrong rig??? Very possible. I would return them. Not a fit at all. Can't put a square into a hole.:giggle: Have replaced o-rings with new many times. No revisions that I know of. Same size, never changed. (RTR 6s "Open" diffs)
O-rings can be reused in most cases. Unless they are very obviuously worn or clearly damaged.
I always use a silicone grease on the o-rings. Some just use some diff oil. Fine enough. Some will use shock o-ring lubes. Like TA's Green Slime if you have that on hand. Lubing the o-rings, they will last longer. Less chance for diff oil leakage at the outdrives. Remember that the Outdrives spin rather fast inside of these o-rings. Equates to much friction on the o-rings. How and why they normally would wear, for this reason. Also a good idea to always use grease on the outdrive shaft before inserting into the diff cup. Tekno does this with their diffs. I always do it. Any diff. Outdrives and diff cups and main gears will last longer.
My spin.:cool:

edited.
Thanks Steve,
You're confirming my what I suspect to be correct assembly practice, but in fact it is not, ..."according to Arrma". The PN for the O-rings are direct from Arrma, I have the complete parts breakdown for my V3 Senton and yep, those are the diff O-rings for sure! I purchased two packages and they're identical and too damned large. Ugh!

As far as a shim behind the Planetary gears, not one of these diffs had them. Going back to the manual, and even "some" 2018 era YT videos, it appears they weren't spec'd for them. My exploded diagrams don't show or specify PNs for them. I did find a couple of videos showing shims being installed, but they all seemed as if this was a mod to "bulletproof" the open diff. One video is actually titled as such.
This has been frustrating. I should've completed this a week ago but have been waiting on small parts, and inadequate assembly instructions has left me searching for others advice. Like I said, my LHS was useless... ( Traxxas fanboys they are.)
I was thrown off by the manual and physical evidence and have been left scratching my head...
When I rebuilt all my TC Sketer diffs they all had shims behind the Planetary ( large) gear. Seems to be a design flaw, IMO. I don't have any new 1/8 scale rigs to tear apart, all my rigs are pretty much vintage pieces I have yet to pull the diffs on but I suspect they are all assembled this way. I sure hope the new stuff has been updated with shims. Between the Mugen shim kit, Arrma diff parts kits, and the multiple O-rings I could've just bought a pair of F/R Jenny's open diffs.

Doing a search for something about Arrma O-rings I was able to find a suggestion for the O-ring problem. It seems this has been a problem with others as well. These are P5 O-rings but it appears that P3 O-rings meant for the 4mm shock shafts actually work better ( PN: AR330245).
Progress, I guess. Together with the Mugen shim kit ( PN: MUGE 0206) I should be alot closer to getting this Senton rebuilt and RTR.

I hope this thread can enlighten someone down the road.
Thanks for the wisdom on the shim kit choice.👍

Post Edit:
My O-rings appear to be flat spotted and thin. Most of them have been leaking, the rear and center diff were the worst.
Using Green Slime also!
 
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Thanks Steve,
You're confirming my what I suspect to be correct assembly practice, but in fact it is not, ..."according to Arrma". The PN for the O-rings are direct from Arrma, I have the complete parts breakdown for my V3 Senton and yep, those are the diff O-rings for sure! I purchased two packages and they're identical and too damned large. Ugh!

As far as a shim behind the Planetary gears, not one of these diffs had them. Going back to the manual, and even "some" 2018 era YT videos, it appears they weren't spec'd for them. My exploded diagrams don't show or specify PNs for them. I did find a couple of videos showing shims being installed, but they all seemed as if this was a mod to "bulletproof" the open diff. One video is actually titled as such.
This has been frustrating. I should've completed this a week ago but have been waiting on small parts, and inadequate assembly instructions has left me searching for others advice. Like I said, my LHS was useless... ( Traxxas fanboys they are.)
I was thrown off by the manual and physical evidence and have been left scratching my head...
When I rebuilt all my TC Sketer diffs they all had shims behind the Planetary ( large) gear. Seems to be a design flaw, IMO. I don't have any new 1/8 scale rigs to tear apart, all my rigs are pretty much vintage pieces I have yet to pull the diffs on but I suspect they are all assembled this way. I sure hope the new stuff has been updated with shims. Between the Mugen shim kit, Arrma diff parts kits, and the multiple O-rings I could've just bought a pair of F/R Jenny's open diffs.

Doing a search for something about Arrma O-rings I was able to find a suggestion for the O-ring problem. It seems this has been a problem with others as well. These are P5 O-rings but it appears that P3 O-rings meant for the 4mm shock shafts actually work better ( PN: AR330245).
Progress, I guess. Together with the Mugen shim kit ( PN: MUGE 0206) I should be alot closer to getting this Senton rebuilt and RTR.

I hope this thread can enlighten someone down the road.
Thanks for the wisdom on the shim kit choice.👍

Post Edit:
My O-rings appear to be flat spotted and thin. Most of them have been leaking, the rear and center diff were the worst.
Using Green Slime also!
Forgive me. I was referring to 6s open diffs. Not 4x4 diffs.:rolleyes: My mistake. 4x4 diffs assemble differently. I'm a bit confused. My V3 6s OC did have shims under the Sun gears.Could have been an un-published revision, commonly done at times, to this day with Arrma. This was when HH acquired Arrma from Hobbico. Things were a mess back then. But agree that the O-rings you do have, are not correct for open diff 6s rigs.
O-rings may have been mispackaged by Arrma. Wrong o-rings placed in the package. Not something new at all. Check with your LHS again. Whatever the reason, the o-rings are wrong anyway.
 
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