Let's say you upgrade from 3.21 gears to OEM 4.10 gears. Could jeep unwarranty your axle? I mean they can NOT claim or prove their OEM gears caused undue stress, they sell the same gears in the jeep.

 

I was talking to a local shop about installing gears in my JK. They said they would warranty the gears - parts and labor - for life ... or at least as long as they are in busines ...

 

It depends on your jeep dealer. I had the dealer install gears for warranty issues and they cover repairs due to it's an original mopar part and installed by a factory certified tech. I have had the jeep in for failure service and never had an issue with the warranty covering it, and that was with the factory rep even coming out to look at the jeep. Talk it over with your local jeep dealer, ultimately it doesn't matter what we say on here it is up to how they are willing to work with you.

 

I believe if a dealer installed a brand new set of factory 4.10s, they would be covered by the warranty

 

Browse this one.

Dealer installed gears, front end seized while driving cross country, which took out the TCase also. Dealers in the town he broke down in denied warranty, original dealer that performed the install denied warranty.

https://www.jk-forum.com/forums/modified-jk-tech-2/transfer-case-gone-105585/

'Your' dealer may or may not warranty the install, but do not expect the factory warranty to cover any damage caused by a gear install. Be sure to get it in writing from the installing dealer, don't just let someone 'say' they will warranty it...