Newbie Yukon XL owner!

I towed my Buick with my 01 5.3 2wd Silverado just fine and would be about the same weight as your jeep + trailer. It had a factory tow package with 3.73 gears though.

The 8.6” rear is fine if you behave and know the g80’s weakness. Take care of it and don’t abuse it and it’ll last forever. I think I’d regear and get an aftermarket trans cooler. You can tie into the factory radiator cooler just like the oem version with an aftermarket kit. With the 6 speed and 3.73 gears I think you’d be in the right spot. My 07 2500hd has 3.73’s and got decent mileage with a 6.0 but also pulled loads that didn’t feel like they were there.

Both the 8.6" and 9.5" are still semi-floaters. They tend to heat up on long tows with heavy loads. My '01 half-ton Suburban, now owned by my best friend, is wearing rear axle number four, precisely due to towing heavy loads. I wasn't overloading anything, was just running pretty darn close to max ratings with 6,000-7,000 lb trailers.

Payload and rear axle weight are the numbers you have to watch. Hitch up a trailer with 700-800 lbs of tongue weight, add the weight of the hitch itself, then throw in the family and some gear/luggage, and you're out of payload and have an overloaded rear axle. Unlike the pickups, the Suburbans start off with more empty weight on the rear axle because of the body and all of that rear glass.

And if you try to crank the weight distribution bars, or adjust the load on the trailer to lower tongue weight, you're just making your rig less stable. Again, ask me how I know.

And with regards to the weakness of the G80, the G80 by itself does not make the axle weak. The G80 is not an axle designation. It's simply a locker that is available in any GM truck rear axle.

I have a G80 in my 2500 Suburban, inside a 10.5" full floater made by American Axle. AA rates the axle to a maximum of 8600 lbs. The limiting factor in the application of this axle in the Suburban is the tires, so I have a rear axle rating of "only" 5500 lbs. The only "weakness" of the G80 is that it doesn't like childish/stupid stuff like donuts, peelouts and wheelspins. Don't drive like a 16 year old, and the G80 will last forever. I have well over 400,000 miles logged on G80 trucks with zero issues.

In other words, don't do this with a G80:

All great info! Thank you. I only plan 50-60 miles towing.
I’m not sure I’m going to re-gear this one. I think I’ll set it up the way I’d like it to look, and think about selling...
Definitely should have gotten on here before I pulled the trigger! But, I might come across a front diff and rear axle out of a wreck too. What code am I looking at for the lower geared rear end?
I originally wanted a 3/4 crew cab Sierra gasser. But it would’ve tacked on about 10g’s to my budget.

NateDavis49686 said:

But, I might come across a front diff and rear axle out of a wreck too. What code am I looking at for the lower geared rear end?

Click to expand...

GU6 - AXLE REAR 3.42 RATIO

GT4 - AXLE REAR 3.73 RATIO

GT5 - AXLE REAR 4.10 RATIO

You'll find those 3.73s and 4.10s out of the older SUVs and they're slightly less wide; the GMT900 has a wider track.

Tow with it as is and then make the changes as you see fit.