Pictures of how to shim a diff.

This is a brief description of how to shim your diffs. I'll do my best to give you a step by step description of each picture.
[IMG]http://pic60.picturetrail.com/VOL1716/11943093/22045460/367354374.jpg[/IMG]
Here is a picture of the diff. and the shims I use.

[IMG]http://pic60.picturetrail.com/VOL1716/11943093/22045460/367354375.jpg[/IMG]
Remove the 4 screws shown in this picture

[IMG]http://pic60.picturetrail.com/VOL1716/11943093/22045460/367354386.jpg[/IMG]
Separate the cases

[IMG]http://pic60.picturetrail.com/VOL1716/11943093/22045460/367354384.jpg[/IMG]
Remove this gear

[IMG]http://pic60.picturetrail.com/VOL1716/11943093/22045460/367354381.jpg[/IMG]
Place shims on the shaft as shown. I usually start with 1 or 2 shims.

[IMG]http://pic60.picturetrail.com/VOL1716/11943093/22045460/367354379.jpg[/IMG]
Slide the shims all the way down until they are against the gear.

[IMG]http://pic60.picturetrail.com/VOL1716/11943093/22045460/367354378.jpg[/IMG]
Insert the gear back into the housing

[IMG]http://pic60.picturetrail.com/VOL1716/11943093/22045460/367354375.jpg[/IMG]
Put the cases back together and insert the 4 screws

[IMG]http://pic60.picturetrail.com/VOL1716/11943093/22045460/367354376.jpg[/IMG]
Check for slop by trying to move the shaft on the left in and out. If it feels snug, check for binding by rotating it. If it all feels good, your done. If it feels sloppy, add another shim. You want it to move as little as possible in and out, while still rotating freely.


Hopefull this post helps those of you with questions on how to shim the diff. I'm not a pro by any means, this is just the method I use.

great pics and explaining! ive never shimmed a diff, but is that the only place that needs shims? i thought i remember reading there was two places to shim.

I noticed that when I fill my diffs with grease they seem a little tighter. Does anyone else fill theres with grease??

You also need to shim the diff side to side, not just pinion depth. Also, you should never shim a dirty diff...always thoroughly wash all grease off before shimming.

Grease (inside the diff cup) will make the diff seem tighter when you spin it by hand, but it is actually less vicious than diff oil, so it will not perform as well as diff oil.

Grease on the ring and pinion is fine, since metal gears need lube, but you only need a little, just enough to coat the gears.

Yes you can also shim the output shafts of the diff, but that very rarely needs to be shimmed. The input is usually the part that wears first and starts slipping.

The ring is harder than the pinion, and the diff moving side to side is what wears the pinion. Pinion depth should only be shimmed AFTER you have the diff itself shimmed side to side. If you can move the diff side to side without the pinion in, it needs to be shimmed.

Hmm. Every time I have had a clicking diff, the process shown above has eliminated the problem. From my experiences the mesh between the ring and pinion loosens up, which is why I shim it. I have never had a problem with the mesh on the internal diff. gears.

This may be a stupid question but why shim?

And where do you get these shims from?

[QUOTE=michindi]This may be a stupid question but why shim?[/QUOTE]

after a while the gears begin to wear and will start slipping. You can shim them to stop the slipping and get more life out of them.

[QUOTE=2IS]And where do you get these shims from?[/QUOTE]

I get shims from my lhs. They are just 6mm bearing shims.

I got the same shims as in the picture from my LHS. 6mm shims.

One thing that I have found with the diffs that makes a big difference is to not tighten the out case to much. It really starts to bind the action quite a bit. There is a fine line between just tight enough and too tight. WIth the outer case, you aren't really needing to keep any liquids in like the inner case. The grease is sticky enough to stay on the ring gear pretty well.

[QUOTE=yzf128r] I have never had a problem with the mesh on the internal diff. gears.[/QUOTE]
I am not talking about shimming the internal spider gears, I am talking about shimming the output shafts, to stop the whole diff from moving side to side in the diff case.

Tagged: Just in case I forget....;)

thanks, great how to!

[[B][URL="http://monster.traxxas.com/showthread.php?s=&threadid=267016"]Here[/URL][/B]] is the proper way to shim your diffs...

When your diff starts clicking what is the best way to find out if it's front or rear diff? Please be as detailed as possible.

Hold your truck planted to the ground watch to see if its the rear or front tires that skip a beat

For me clicking on hard acceleration is rear... And clicking on hard braking is the front.

Tks for input guys I'm going to give those recommendations a try and see if I can figure out where mine is coming from.. sounds like it's on the acceleration, will know more tomorrow..

i'm sure saving this post !!! great stuff guys :thumbup: