GMT800: 1/2T vs 3/4T for towing 7K

I tow the Zoomboni in an enclosed trailer with a 2004 Suburban 2500 QS.  Coming from a 99 1/2 ton Suburban the difference is astonishing.  The chassis composure is completely different.  It still feels underpowered compared to a diesel but it solidly stays planted to crosswinds and buffeting.  Brakes are excellent and have plenty of extra when needed.

If you can find a functioning QS truck it really helps reduce the feeling of bulk and enhances parking lot maneuvers.   But they are slightly rarer than hens teeth at this point.

Quadrasteer is amazing. 

A customer of mine had a QS truck that she put an insane amount of km on. I think we replaced the balljoints at around 350,000km and the truck is still going. I think it's nearly double that amount now.

There's a shop in the states manufacturing most of the unobtainium parts for them now.

I think Duraburb has adding a QS axle on their option list when they build you a Duramax equipped Suburban.

Many of the 1500s are geared higher for better fuel mileage, If you are doing regular towing above 5k, I'd opt for the 2500. I have been eyeing Escalades, Denalis, and Avalanches of this era, as they come with all the fixins 9.5" axle, 4L80, better gearing for towing, LQ9, etc. Definitely get a good WD hitch and brake controller.

In reply to SouthSideDIY :

Yukon Denali and Escalade have the 4L65e, not the 4L80e. They also have the 3.73 rear end which is worse for towing compared to the 4.10 that's optional on some of the trucks and the 2500 SUVs. The 1500HD trucks get the 6.0 LQ4 with 4L80e instead of 4L65e, but still have the light duty axles. The LQ9 comes on mostly on the 02+ Escalade AWD, Silverado SS, 05-06 Sierra Denali, and Silverado/Sierra with the HO/VortexMAX. Otherwise the 1500HD, 2500 trucks and the Yukon Denali get the LQ4.

In reply to SouthSideDIY :

In addition to what da_johnny_boy said, even the GMT900s get the 8.6" rear end if they are AWD, which most escalades and denalis are. Only the RWD get the 9.5. Notable exception is the 2009 Chevy Tahoe LTZ 6.2, which has the uniquely desirable drivetrain of 6.2, dual range transfer case, and 9.5" rear end. They only made a few hundred of them. I looked for one for a while, but the only ones I found had rust issues.

My use case required a higher axle weight than the 8.6" 10 bolt can handle - I know because I killed two of them thinking I would be okay. For me, the 2500 ended up being the only practical way to get 4 driven wheels and a big enough axle in a GMT800 or GMT900. Depending on the engine, 2500s got either a semi float 9.5" 14 bolt, full float 10.5" 14 bolt, or the big AAM axle with the 11.5" ring.

Brake_L8 (Forum Supporter) said:

I've been watching this thread and finally have a few minutes to chime in. I've got a good bit of experience towing and review new trucks/SUVs for their trailering behavior on YouTube. My first tow vehicle was a GMT800 Yukon Denali (short wheelbase) with the 6.0 / 4L65.

Wheelbase wise - you are looking at 116" on Tahoe vs 130" on Suburban. Big difference and for your use, Suburban or Yukon XL all day long.

Payload is your other big concern given you have two kids so presumably a family of four plus all your stuff plus the tongue weight of the trailer. The maximum listed payload for a 2005 Suburban 1500 is 1,732 pounds. Travel trailers/campers are notoriously more heavy than manufacturers claim so let's assume 6500 lbs for yours. Take 10-12% tongue weight (780 lbs at 12%) and your leftover payload is 952 lbs. You're gonna get close to max payload with the whole family and luggage in there. What if the kids want to bring a friend? Or you bring the grandparents one weekend because you've got that third row? I... probably wouldn't.

My other potential sticking point with the GMT800s is the drivetrain. Those four-speeds have some pretty long gears; they are fine until they're not regarding powerband. I had one memorable instance with my Denali (with an open trailer + Volvo 240 in the mountains) where my two options were about 42 mph in 3rd or 60ish in 2nd. It was lugging in 3rd so I let it scream in 2nd. Painful. The 5.3L would've been worse.

I hate the GMT900s but they do gain the 6-speed automatic which helps make the most out of the engine and tows far better as a result.

I guess if you have to have a GMT800 – which I understand, they look fantastic and IMO are "peak GM truck" ever built – I'd recommend a Suburban 2500 and ideally with the 8.1L. At least if you got one with the 6.0 it'll have payload to spare and the stronger 4L80 transmission. 

Typical advice here about weight distribution + sway control hitch and electronic trailer brake controller apply. Don't tow without 'em.

Great post, thanks. I do like the GMT800 but am not absolutely attached to them. Can you recommend anything else under $15K that can do the same job as a 2500? Must be:

4WD

SUV/3rd row (car camping capable)

Dead nuts reliable, readily available parts

Towing capacity as mentioned above 

Excursion but good luck finding one.

In reply to nsogiba :

Sounds like you need an E350 passenger van