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Old 12-03-2013, 09:01 PM
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has anyone had issues with the Kyosho diff o rings swelling excessively ??

That seemed to be the cause of all my handling issues
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Old 12-03-2013, 09:25 PM
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Wow, weird. I'm running them, but only had them in for about 2 months. How long have you had them in? I also reshimmed my diff as well. I replaced the internal shim with a .1mm shim. Made my diff smoother.
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Old 12-03-2013, 10:02 PM
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Originally Posted by JimmyMac View Post
Wow, weird. I'm running them, but only had them in for about 2 months. How long have you had them in? I also reshimmed my diff as well. I replaced the internal shim with a .1mm shim. Made my diff smoother.
Did you feel any handling different before and after you re-shim the diff?
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Old 12-03-2013, 10:40 PM
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Originally Posted by haura415 View Post
Did you feel any handling different before and after you re-shim the diff?
When I first got the car, I had handling consistency issues along with the rear end wanting to drift out a lot. Some of this may have been tires, but making the diff smoother did help out with the setup. It seemed like no matter what oil I put in the rear, whether it was 700, 2000, or 3000, it always felt the same or close to it. It was never smooth and free like a few of the Top, Xray, and Tamiya gear diffs at the track. Reshimming smoothed it out and let the viscosity do the work instead of gear mesh. If this makes any sense. Now I just run Mugen 2000 and concentrate on other handling changes.

I think I'll post up an updated setup for my local carpet track tomorrow night. If feels real good and consistent. But it's gonna be changed this coming weekend for more setup testing. It's aimed at medium bite carpet tracks running 17.5 blinky.
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Old 12-04-2013, 02:33 AM
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Originally Posted by JimmyMac View Post
Wow, weird. I'm running them, but only had them in for about 2 months. How long have you had them in? I also reshimmed my diff as well. I replaced the internal shim with a .1mm shim. Made my diff smoother.
only had them in for 3 weeks ??

On my cars first outing last month using the stock o rings it was great, then after that I was able to find a shop that had the Kyosho o rings in stock so I replaced them after that and its been progressively getting worse,

Put new kyosho o rings back in today and its back to how it should be, nice and free.

I had the same problem with Associated o rings they would just swell in about 3 weeks, but as there is 2 o rigs in the associated diff on each side I just removed one, and it fixed the problem. Green slime never seem to help.

I will hassle CraigM on Saturday and see how tight his diff feels.
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Old 12-04-2013, 02:49 AM
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hm strange my kyosho o rings are holding up fine since fitting em!
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Old 12-04-2013, 09:10 AM
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I fitted Kyosho orings way back, maybe March? Haven't even considered changing them since.
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Old 12-04-2013, 10:22 AM
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What brand oil caused swelling Evochick ?
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Old 12-04-2013, 12:01 PM
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Originally Posted by RedBullFiXX View Post
What brand oil caused swelling Evochick ?
Good point.. Associated ....
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Old 12-04-2013, 12:20 PM
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im using associated, again no swelling?
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Old 12-04-2013, 12:31 PM
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I have also used AE silicon lube in the past
Thoroughly green slimed the o-rings first
Not a drop has leaked, and no swelling, as far as I know, no silicon has touched the o-ring
On disassembly, everything looks as originally built, even after months of running
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Old 12-04-2013, 12:48 PM
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About the geardiff, when i put the outdrive in and the kyosho o-ring then the outdrives still spins free. When i put the shim on and put the pin in the hole the outdrive binds a little bit.

This can have 3 reasons

1. The shim is to thick ( mine are 0.2 mm)
2. The hole on the outdrive is at the wrong place
3. The molded housing is to big.

I sanded the housing a little bit at place where the outdrives come out.
This solved the binding of the outdrives.
Then i sanded the biggest gears and this made the diff al little less notchi.

@ jimmiymac

Did you replace the original 0.2mm shim with a 0.1 or did you add a extra 0.1mm shim on top of the original?
If you did the first then i achieved the same, only whit a lot more work. It would have been easier to just replace the shim.
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Old 12-04-2013, 01:19 PM
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I've seen the notchy diff, but the 2 cars I have, feel like a perfect ball diff, butter smooth, assembled per directions
Could be tolerance issues with some parts ?
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Old 12-04-2013, 02:09 PM
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did a recent diff rebuild, butter smooth
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Old 12-04-2013, 02:13 PM
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Originally Posted by sitting duck View Post
About the geardiff, when i put the outdrive in and the kyosho o-ring then the outdrives still spins free. When i put the shim on and put the pin in the hole the outdrive binds a little bit.

This can have 3 reasons

1. The shim is to thick ( mine are 0.2 mm)
2. The hole on the outdrive is at the wrong place
3. The molded housing is to big.

I sanded the housing a little bit at place where the outdrives come out.
This solved the binding of the outdrives.
Then i sanded the biggest gears and this made the diff al little less notchi.

@ jimmiymac

Did you replace the original 0.2mm shim with a 0.1 or did you add a extra 0.1mm shim on top of the original?
If you did the first then i achieved the same, only whit a lot more work. It would have been easier to just replace the shim.
I replaced the .2mm shim with a .1mm shim. Mugen diff oil. I think I slightly ran the internal gears on a file or sandpaper to remove any burrs on the back side. That's about it. No major sanding. My diff feels smooth. Just not free like my TA05 gear diff with the same orings (Kyosho) and same Mugen 2000 diff oil. No worries though. My car runs great now.
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