no, sorry I have no part number. I buy mostly several shims in different dimensions at my rc-dealer.
It is like a washer but a lot thinner and different sizes and thickness.
I do shim also other parts on the rc-car. For example the space between the hex-bulk (hex wheel adapter) and the bearing.
And so on. So you need to measure the diameter of the shaft and afterwards buy different shims in several thickness.
0,05, 0,1, 0,15mm if you're dealer have so. Then you can shim you're diff very well, because you have all choices below to 0,05mm.