I've never replace U Joints myself and I would rather have the HUMMER dealer replace the U Joints correctly and also I know they will use the correct factory replacement parts. Not some cheap aftermarket parts that were not factory standard like your talking about HumminNBoatin.

 

This may be an old thread but for anyone reading it currently like myself. Yes a Milfs ujoint is only around $20 and better than the factory "CHEVY" standard gm ujoints.

 

Wish I could have replaced them for ya. Shoot.. Someone charging half of that would be making good money for the job.. If you have any mechanical skills at all you need to start looking up DYI videos and doing some of this stuff yourself.. Not only will it give you knowledge, you will save alot of money, and you will be able to say, yeah, I did that..