I just went on a ~700-800 mile trip with my custom made heavy duty receiver hitch carry-all rack. Rack weighs ~100lbs and load was ~200 lbs. The rear of the vehicle was squatting about an inch or so lower than normal. When I got back home after driving for about 250 miles non-stop, I smelled hot rubber. I looked at the rear tires and the inner tread on both tires is cupped, presumably from the load...and they were quite warm to the touch. They are properly inflated and the OEM receiver is rated for up to 500lb tongue weight, so I was well within the limits. These are original tires with lots of tread left at 33K miles. I've owned plenty of GM SUV's and trucks and have never had this happen before. In fact, with a common axle and leaf springs, I don't know how this is possible.

Does anyone know of a way to boost the carrying load of the rear suspension while loaded, but not comprimising a smooth ride under normal conditions (no load)? Thanks, Will


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i have to wonder if the tire was underinflated for the load

 

You need more tire air psi when towing

You can add an airlift setup that is adjustable when towing. On my H2, I have the airlift coil spring sir bags that I can manually adjust. They were only $80 and easy to install. They make them leaf springs also.

 

First of all, I have to say I really like the rear rack! Very nice job!!!

When I had my H3, I towed a 2 place enclosed snowmobile trailer with sleds for 5 hrs and didn't have any issues, now my tongue weight maybe be less distributed as yours per say, but you should have been OK. Maybe you did need a little more air in your tires. Mine also had the Adventure Pkg with the factory off-road suspension too.

 

That sounds perfect! Do you have a link? I was thinking airbags all along, but they tend to be very expensive. Will

 

Thanks! I think that is quite possible. The tires were all at 34psi when I left Charleston in 74 degree weather. When I got to the Smokies, it was in the mid 30's and the low tire pressure warning light came on. Dumb a$$ me, I had a 12 volt compressor with me! I should have rechecked in the higher altitude and lower temp region. Now I will get to listen to the tires hum until time to replace.

 

32 psi is really just the best average for both mileage and ride, if your towing you should really bump the tire up to 40 psi when ther tire is cold or with in a half mile of starting your trip.. Look at yourtire it will tell you what the max psi is for the tire ..Not GM's recomended pressure but the tire maker.sspec

 

I run exactly 38 PSI cold all the time with the 33 Duelers. Yep I feel a bit more of the pot holes, but my MPG is better.

The TPMS warning answersyourquestion for me.

 

I also have been running my 33's at 38 PSI cold, that way when the temp drops to -30C the low pressure inicator light doesn't come on. I was running at 36 PSI but the light was always coming on till I'd driven about 10km and the tires had warmed up a bit.

 

I'm running 40 Psi cold it has a harsher ride but it has better MPG andtruck feels more responsive