Notorious Shimming too tight

[blakeaowen15]

When I’m shimming my diff, how do I know if I have it too tight in the end?

 

[Killacam]

When I’m shimming my diff, how do I know if I have it too tight in the end?

It won't turn

 

[blakeaowen15]

It won't turn

Any clicking sounds or ways I can look to see, I’ve heard you can have it too tight but will still turn?

 

[Hector_Fisher]

Does it roll smoothly without seeming to "catch" on anything? That's ultimately what you want. As tight as possible without increased resistance gives you the most tooth engagement without creating extra stress on the teeth from them ramming into each other (binding).

Generally a good way is to keep adding shims one by one, feeling for smoothness every time. Once you add a shim and it doesn't roll smoothly anymore, go back and take that last shim off, and you should be good.

If the gears are ungreased, you can also listen for a light click/clack when you rock the gears back and forth.

 

[Camaroboy383]

For diffs "0" lash is ideal.. pinion (input) bearings yield quickly and will ease off on the mesh increasing lash.. the closer you can get to "0" increases your chance of ring and pinion longevity.... zero lash is not to tight in these cases due to bearing yield..

Start with 1) .2 shim and add whatever it takes to achieve no backlash..
It's the easiest way to explain it..

Before any of this is even done your input bearings (assuming they are good or new) should be preloaded...

Loosen the input cup grub screw, use a thumb and pointer finger to compress the cup onto the pinion (input) shaft... With moderate pressure on the input assembly, tighten the grun screw.. this will preload your input bearings, allowing no play in the input at all.. a wiggle test on the input cup will confirm your preloaded...

If you would like to take it a step further you can increase heal to toe tooth engagement by shimming the pinion, either behind the large internal bearing or behind the gear itself.. the preferred method would be .2 behind the bearing...

If you also choose the latter method, start from scratch with no shims on the diff carrier stack, and work your way in as mentioned above...

Hope this helps and doesn't send you further down a rabbit hole...

 

[parcou]

When I’m shimming my diff, how do I know if I have it too tight in the end?

This might help

 

[Camaroboy383]

This might help

Ughhh, why did I type all that... This was so much easier... ...

This is for sure the proper way, and you can tell he has done a few real 1.1 diffs in his days.. ..

You found yourself a good one parco, he is a smart man... pay close attention to people like this, proper wealth of knowledge..