New Yukon XL owner. Problem with 3.42 diff

[OEMTim]

Hey, everyone. My name is Tim. I just purchased a 2005 Yukon XL 1500 SLT 2WD to use for family road trips and to tow my race cars. I bought it on eBay and, unfortunately, the seller wasn't very accurate with his description of the vehicle.
In any case, I'm still going to keep it. However, I'm getting a really loud noise from the rear end. Checked for fluid and there was none. Added that, but the noise is still there. I even removed the driveshaft and checked u-joints. Both needed to be replaced, so I did that also.
I'm trying to find out what vehicles have a compatible 3.42 diff or if there are any recommended upgrades available out there.
I own a European car parts store and this is my first foray into the domestic side.
Any info would be great!
Sorry for the long backstory!

-Tim

 

[01ssreda4]

Any 8.5/8.625 diff will work. It needs to be from year model 99 and newer, as the older differentials have slightly different bearings. You need to check the options on the truck to see if it has an open differential (one wheel peel) or a gov-lock locking posi-traction which was an option. They sell for about 2-300 used if it needs to be replaced. Unfortunately if it was ran low on gear oil it may need new bearings as well.

 

[OEMTim]

Thanks for your response.
I haven't found any for $200-$300. In fact, most that I've seen are almost $500. Anywhere specific you suggest I go look?

 

[01ssreda4]

all day on ebay, just make sure its the later model after 99

http://www.ebay.com/itm/GM-8-6-8-5-...ash=item4b189df1b1:g:618AAOSwq1JZIxVK&vxp=mtr

 

[01ssreda4]

here's a new one for 300, aftermarket unit

http://www.ebay.com/itm/CHEV-GM-8-5...ash=item234e3490fe:g:2PsAAOSwYlJW5xwU&vxp=mtr

 

[OEMTim]

I guess most people don't list them as GMC Yukon XL differentials lol

Thanks for sending those over. I'm actually an Eaton dealer. Maybe I'll go that route.

 

[01ssreda4]

yep, eaton will work fine