H3 Towing Help

[HoosierH3]

I'd tend to agree with Matt19. Very well written. You don't want to push the limit to far. I've only had the chance to pull about 3500# so far with no issues. I did install an electric brake controller which helps considerably on the stopping part. On the other hand though, I would think that GM placed the actual limit modestly, that the H3 could actually handle a little bit more weight?? so if your close, it may be ok? Obviously, I would not advise going to far over though....

[MiamiH3]

The total Dry Weight of what I want to pull is 4,439lbs. Add about 400-500lbs of accessories, so I will be pushing close to 5,000.

I will be adding Weight Idstribution and Sway Bar for sure and thinking about electric brakes.

The Hummer web site does say if you plan to pull more than 5,000lbs use a weight distribution and sway control.

[RubHer Yellow Ducky]

Originally Posted by MiamiH3

The total Dry Weight of what I want to pull is 4,439lbs. Add about 400-500lbs of accessories, so I will be pushing close to 5,000.

I will be adding Weight Idstribution and Sway Bar for sure and thinking about electric brakes.

The Hummer web site does say if you plan to pull more than 5,000lbs use a weight distribution and sway control.

In what area of Miami are you?

[Huck BB62]

About towing the H3, I towed ours, with a bed FULL of krap, my 18' car hauler packed full of krap, and the H3 packed FULL of krap from Bfield to Oregon. Grant's pass is pretty harsh. My 2500 did it just fine, but it is a diesel. The H3's only 4700lbs! (I had about 10k on total)

As far as towing 5000 lbs. One thing that bothers me on the H3 is no tow/haul mode. They put this on every other GM vehicle I have. It changes the way the tranny acts. You can do this yourself, just row the shifter by hand. Start off with the load slowly, it REALLY saves the clutches in the tranny. Let your engine wind up pretty high before you go to the next gear. When you're stopping, downshift with it to aid in stopping too. The tranny's plenty tough enough, and the dang axles are surely low geared enough, it's just not supplied with the tow/haul mode. If you're in doubt, put the biggest stacked cooler you can buy on it.

Put a finned aluminum rear diff cover and use synthetic (the shop guys tell me that synthetic's in there from the factory, who's to say?). Tests have shown that these two things lower operating temps a LOT.

Pump up the tires to maximum, this really helps the way the H3 will handle during the tow.

Get a Prodigy brake controller and make sure your trailer brakes are well maintained and adjusted.

No problems. KEEP YOUR SPEED DOWN. Bad things happen so fast when you're towing too fast. One of the absolutely worst things to do is to too lightly load the tongue. I bought a tongue gauge. You should always have 10% of the trailer weight on the tongue. If you don't, it's going to be sway happy and swat you badly.

Think about it, that tranny's used in half tons. 225hp is far more than a 350 had during the 70s.

Trailer brakes are required on anything over 2000lbs here in Cal, they should be everywhere as far as I'm concerned.

[evldave]

I've pulled 6k for about 70 miles. First part was winding country roads (30-45mph) the last half was freeway (60-70). Powerwise it was fine. Control was fine (it was a flatbed, with a larger trailer I'd be concerned). The biggest issue was the tranny and keeping it in gear. Plus I'd say the tranny has never been the same. Sure, it's under warranty, but I'd highly recommend AGAINST towing a trailer that large on a regular basis.

Just my experience and 2 cents. If I was towing a trailer that large regularly, I'd get a 3/4 ton vehicle - sure you can probably do it, but you are at the maximum range of the truck and have a higher likelihood of 1having an issue - why not get yourself an H2 and have some piece of mind

[f5fstop]

The trans does NOT have synthetic fluid from the factory. The diffs do!
As for synthetic helping trans shifting...that has never been proved in an automatic. Trans fluid is a heck of a lot more than a slippery fluid. It has to be slippery, but also have enough friction material to make it not cause slippage.

[Huck BB62]

I guess I never made myself clear, I was talking about the rear diff with the synthetic. This does bring up another couple of points though. Synthetic tranny fluid is available. I use it in everything I have, the Royal Purple. In my Allison, my gauge dropped some. It's not a very wide range gauge but from what I experienced, it shifts smoother, and runs cooler.

More about towing with the H3: Never ever ever let it tow between gears. This is when it's not locked up and it's making a lot of heat. If it won't hold top gear, don't try to make it. Just shift it down to a gear that it'll stay locked up in. If it's huntin', rev it!