[NutoTurno]

If the cases are ok, then just change the gears, but do both.
The crown wheel teeth may look fine to the naked eye, but they will have a wear pattern in them.
If you reuse the crown wheel, you'll have trouble getting a good tooth mesh.

 

[NutoTurno]

Hey ozymax,

I finally got the ring/crown gear in. Was lucky to get the last one from a place outside of Boston USA. Being from Ontario Canada it was tricky lol. (god dam covid)

My local dealer gave me more than enough shims to deal with. We bought the tool to measure the backlash, but not the preload at this point.!

I am concerned now of shimming properly. As I see on the web, BRP did not shim properly from factory. I only have just over 2000km on the quad

Any advice on how I should proceed would be greatly appreciated

 

[ozymax]

Now's your chance to put things right.
I'd reuse the factory shims in their original location to start with and adjust from there.
You mentioned about replacing the bearings before, I'm assuming you've replaced the pinions needle bearing?
If you had and then run it with the old worn pinion, then that needle bearing is probably damaged, so I'd replace it again.
You stated that you have a workshop manual, so just simply follow the procedure and you should be fine.
One last thing, think clean, clean, clean when you do the work.
I am a little curious as to the low km's for the diff. My 2013 Outty has almost 20,000km and no sign of diff failure at this stage.
Of coarse, now that I've said that.........