diff shims, where do you get them for a revo

everyone talks about diff shimming. i searched Google for revo diff shims and came up with nothing, where are these shims? i apparently need them

[George16]

It doesn't have to be revo-specific. Just measure the shafts and buy the shims from tower or Amain.

For example, the buggy/truggy diffs use 8x10mm, 6x8mm and 4x6mm shims.

? ok i'm still confused what diffs does a stock 3.3 revo use. i thought there would be one size for the revo, so there are 3 places to shim?
thanks

[lincpimp]

You have to shim the diff in various places to remove slop, and also create a good mesh between the two gears. I will limit this explanation to the ring and pinion gears.

On a revo, the shims used to adjust the side to side fit of the ring gear/diff cup assy are 10x12mm. The pinion is 6mm in diameter, so something like a 6x8 shim would go there.

The trick is to first shim the ring/diff cup in the housing without the pinion in there. All you are looking to do is to figure out how many shims give it a good snug fit. Place the shims between the bearing and the ring gear. When you have that done, reinstall the pinion gear and see it is too tight against the ring gear. If it is, move one shim to the cup side of the diff, between the cup and the bearing. That will move the ring gear away from the pinion, to the side, and free up the gear mesh a bit.

Heres the tricky part. You need to eyeball the pinion, and determine if it is lined up with the teeth on the ring gear. It may be sitting to far forward, and require a shim between it and the inner bearing. That would move the pinion farther into the diff case. It makes sense when you do it.

You want a good mesh, but not too tight. And when you get it right, use some good synthetic grease on the gears.

[George16]

I use yellow or blue marking compound to check for proper tooth mesh between ring and pinion and Gorilla Snawt as grease for the ring gear.

[blueb8llz]

heres a pretty good read up.
http://monster.traxxas.com/showthrea...ght=shim+diffs

awesome thanks, this diffidently sets me in the right direction, thanks for the write up lincpimp

[lincpimp]

Originally Posted by e-rev project

awesome thanks, this diffidently sets me in the right direction, thanks for the write up lincpimp

Gotcha, you are very welcome. I need to do a pictoral how to...

[RUSTY XL-5]

Thanks for the link, I always wondered how to shim a diff properly. :)

[blueb8llz]

Originally Posted by lincpimp

Gotcha, you are very welcome. I need to do a pictoral how to...

yea ...that would be awesome.

[lincpimp]

Originally Posted by blueb8llz

yea ...that would be awesome.

I will do it next time I put a LST diff together, and maybe do a pair of revo diffs too.

[mikey09120]

Originally Posted by blueb8llz

heres a pretty good read up.
http://monster.traxxas.com/showthrea...ght=shim+diffs

haha. anyone wanna copy and paste. i was banned for the protest of suicideneil

You can dnload UE's instructions of building either a 6 or 8 spyder ultralight diff. They have plenty of pics and are explained well enough to understand what you're trying to accomplish.

The only thing no one ever mentions is george16's trick with marker/dye to dbl check mesh. You kinda need to know what you're looking for to use that, but it provides a visual on locating pinion on the ring and quality of the mesh.

If you've ever done a 1:1 diff you'll know what I mean.

[lincpimp]

Originally Posted by Duster_360

You can dnload UE's instructions of building either a 6 or 8 spyder ultralight diff. They have plenty of pics and are explained well enough to understand what you're trying to accomplish.

The only thing no one ever mentions is george16's trick with marker/dye to dbl check mesh. You kinda need to know what you're looking for to use that, but it provides a visual on locating pinion on the ring and quality of the mesh.

If you've ever done a 1:1 diff you'll know what I mean.

I don't think anyone makes a small enough dial indicator to set the backlash

It is important to see the mesh pattern, but generally a full size vehicle is set that way to minimize noise. It does help longevity... But a properly shimmed diff will do just fine. I generally set the pinion depth so that the teeth match up with the ring as evenly as possible, and the diff cup does not rub on the end of the pinion.

[madmaxx]

i've been looking for this kind of help for a while!

thnx