Just be aware that some 4x4 shops will only guarantee work if they supply all parts.

Unless you are doing the install yourself, choose a shop before buying gears so you each know what to expect.

 

That is a great point. I do have a local 4x4 shop that quoted me the install only. It would be surprising that a shop wouldn't at least guarantee their own workmanship though.

 

It's an issue of whether the gears 'you' supplied were the cause of the problem, and how to handle who is responsible for what. If they buy the gears, they have positive control from the mfg/vendor to the shop to the diff, and then right back to the mfg/vendor for any problems.

When I was pricing a gear install at all the shops local to me, (gears that I supplied), I ended with shops who:

Would not install customer supplied gears.
Would install, but charged more for labor than if they supplied.
Would install, but no warranty.
Would install, but shorter warranty than on gears they supplied.
Would install, same price and warranty as gears they supplied. (but their price was $400 more than anyone else...)