Rough Country 3 inch lift

I need help figuring out the 10-15mph vibes. Keep reading that axel shims will fix my problem. The blocks in the back already come angled. Do I need more on top of that? All U joints seem to be in good order. Double-checked all bolts that were messed with during the install. If I do need to add shim on top of the blocks, what degree would I get?

 

Maybe a diff drop or CB drop.

 

Does that require an angled shim as well?

 

I would start by doing a carrier bearing drop because its cheap and easy to do

 

Thanks, I will try the CB drop first. Does that require an angled shim?

 

https://bilsteinlifts.com/shop/toyo...RzP9A_ElrCeZEwBLJJnTdgX4pJZKytFyPQaAtJt8P8HAQ

 

Much appreciated!!!