Differential shims source
 

Does anyone knows where I can source a full set of shims for diff? I'm planning to replace my final drive, but a full set of shim is made of 22+46+46 different thickness and I have been asked around 5€ each in Subaru!

Are you doing the work yourself or taking to a diff shop?
And did you already get a ring and pinion?

There are no diff shops in my city, a mechanic will do it for me. Yes, I have the final drive.

If you find an alternative source other than Subaru I'd be keen to hear it! When I did my diff and fd I bought a select few sizes for $5 each from Subaru!

Your local Subaru or Toyota dealer will be able to order a full set for you.

Have you priced the Toyota equivalent? You also don't need to buy the shims ahead of time, if that's what I think you're doing. The mechanic will know what size shims you'll need when it comes time to install them. You mentioned the word set, and a set of all the various sizes would cost a small fortune. Hope this helps. I got my 4.56 stuff from Weir and he sent along a listing of the Toyota shims and their part numbers. Also, sometimes installers will have shims already on hand that they've removed from other rears that had to be serviced. IIRC some of the shims are 8 to 11 US $ each, so you don't want to buy any that you won't be using. Good Luck!!

Now, this is my thinking: if you don't need to replace the diff bearings (ex. new car), diff backlash will be fine of even with new gear ring. You'll probably need new shims for pinion preload. Now, if you're lucky, your diff preload could be fine, if not, measure the distance neded and buy just the 2 shims.

Is this correct? This will costs you around 100$/€...

I've setup two different rears for a brz and both times the pinion shim that came with the diff (in both cases a 1.97mm) always gave the best pattern. Side shims I've found usually a set of 2.80mm - 3.00mm gives you enough of a range to get your backlash and preload to where you need it to be. Bearings are fine to reuse if they're in good shape but its not a guarantee you won't need to use different set of shims because you're switching to different gears. I'd also recommend a solid pinion spacer/ w shims from weir or cusco. Once you find a shim size that gives a good backlash value, the second shim should go about 1/2 to 2/3 of the way in by hand and then needs to be tapped in with a hammer the rest of the way. Ideally you should be picking up a a couple additional in*lb bearing preload in addition to whatever you measured your pinion preload to be. If your pinion preload and total preload are the same you probably didn't use a thick enough shim. This is a great resource:
https://demos.starbase7.net/t3Portal..._rm_index.html

I'll also add that both times I switched to a different set of oem toyota gears, so I can't guarantee that a set of weir, motive, mfactory gears are manufactured the same way and therefore might need a different pinion shim. Either way final setup should be checked with marking compound to see if the coast and drive pattern is centered.