"New" Tow Vehicle!!!

[66Overlander]

We finally got our 2005 Hummer H2 today!!! We went for Pewter so that it looks good with an Airstream behind it, even though we won't be pulling it too much. I'm gonna try to get some digital photo's of the pair hooked up so I can post the, but it may take a week or two.

And actually, I don't know if I should call this a "new" tow vehicle, because while it is "new", we don't have an "old" tow vehicle, so it's sort of more like a "first" tow vehicle.

Anyway, tomorrow, I going to get a new hitch shank and head so that the trailer will tow level. The hitch receiver on the H2 is much higher than what the PO's must have used to tow the Overlander, so the hitch we received with the trailer won't work "as is". If we tried to use it, the hitch ball would be at about 30" off the ground, not the 20.5" we need.

We're so exicted!!! Now we just have to get some miles on this beast in the next two weeks to break in the motor and transmission before leaving for the WBCCI International. Somehow I doubt that'll be a problem.

Joe

P.S. Did I forget to say ???

[Big Dee]

Congrats! Can't wait to see some pics.

[66Overlander]

No photos yet (still too busy spending every waking moment that I'm not a work working on the trailer . . .), but I now have a hitch with the a proper 6' drop shank (which gets the trailer perfectly level) and have pulled the Overlander perhaps 20 miles. I'd don't have any real prior experience towing trailers of this size, and I haven't yet had the combo on the expressway, but so far the H2 seems to handle the Overlander very easily. I've towed it with and without the trunion bars and found it to feel almost the same. I intend to tow with them, but had to get the trailer to the hitch dealer for adjustments before I could install them.

Joe

[53flyingcloud]

Originally Posted by 66Overlander

No photos yet (still too busy spending every waking moment that I'm not a work working on the trailer . . .), but I now have a hitch with the a proper 6' drop shank (which gets the trailer perfectly level) and have pulled the Overlander perhaps 20 miles. I'd don't have any real prior experience towing trailers of this size, and I haven't yet had the combo on the expressway, but so far the H2 seems to handle the Overlander very easily. I've towed it with and without the trunion bars and found it to feel almost the same. I intend to tow with them, but had to get the trailer to the hitch dealer for adjustments before I could install them.
Joe

Joe,
Congrats`!
Sounds like it's a perfect pair~
Which engine did you get with the H2? gas or diesel?
If you got the diesel, I have a link you might like on the web for the H-diesel. I'm sure you'll enjoy it..
Again, good luck on the awesome tow~
ciao
53FC

[66Overlander]

The H2 only comes with the 6.0L gas engine (no diesel).

Anyway, we just got back from the WBCCI International Rally and two additional weeks of vacation after it. When we get our pictures developed I will scan some into the computer that I can post them to finally show the H2/Overlander combo.

Anyway, on this trip we put about 1300 miles on the H2 with the Overlander "in tow" and have to report that it pulls like a dream. Never any sway with side winds or when semi's pass.

Based upon recommendations on this web site, I pulled with "tow/haul" engaged and in 3rd gear rather than overdrive to save wear and tear on the 4L60 tranmission. I was impressed to get almost 10 mpg at 60 mph doing so, which didn't seem bad considering that the H2 would probably only get about 13 mpg at that speed in Overdrive without the trailer in tow. The trans temp never exceeded 180 degrees F. That got me wondering if I could tow in overdrive in the flat areas without hurting the trans. I tried it for a little while and got at least another 1 mpg out of it, ever closer to the "no trailer" fuel economy.

If I watch the trans temp gauge religiously, is there any reason I cannot tow in OD in the flats? Would the more frequent locking and unlocking of the torque converter still hurt the trans even if the trans temp stayed reasonable (<TBD degrees)? Any thoughts would be appreciated.

It probably doesn't matter much in the end anyway, given that we are not "full timing" it. The difference in fuel ecomony for perhaps 2000-3000 miles towing per year won't add up too quickly, but a transmission rebuild is definitely worth avoiding if at all possible.

Joe

[millionairstream]

I have used several different tow vehicles, and on flat ground, never experienced a problem with towing a trailer of under 4500lbs at 60-70 mph in OD or 5th gear- depending on if its AT or stick. The problem comes when the trans starts shifting in and out under load. They say the Dodge 5 speed has a nut that backs off if you tow it in 5th, but that you can remove the tailshaft, tighten the nut back up and apply some thread lock and its over with- one guy said he tacked the nut with a weld and it was fine.

Can't you get an Allison in that model yet? That would be the way to go if available- probably if the ever offer the Duramax...

[uwe]

Joe,
I tow with the same transmission. If you watch trans temp, and RPM, then you'll notice right away when the transmission is not happy towing in OD.
I believe that when it's flat, you can tow in OD. As soon as the trans starts slipping in and out of OD on slight hills or strong headwind, you should pull it to 3rd.
I don't have the tow/haul mode on my Suburban, so I can't offer advice on that.
It largely depends on where and how you tow.

[66Overlander]

Here are a couple of photos of the Hummer and Overlander in front of the Mackinac Bridge . . .

[eaglerab]

i dont think there is a tow vehicle that can outlast an airstream

[Tarheel]

What is the towing capacity of the H2? It would look great pulling my 34' but the old ones wouldn't tow 10,000 lbs.

[Minnie's Mate]

Originally Posted by Tarheel

What is the towing capacity of the H2? It would look great pulling my 34' but the old ones wouldn't tow 10,000 lbs.

Max Tow=6,700#
Max tongue=700#
GCWR=14,000#
Weight distributing hitch and sway control required for tailers greater than 5,000#. Trailer brakes required for trailers over 2,000#, yada, yada, yada.

[john celano]

Now that some time has past - do you still like towing your 25' with the H2? I'm consisdering buying a 06 SafariSS '25 and doing this same pairing. I just posted a question about this topic on another thread. Are the weights significantly different on your A/S as compared to the newer ones?

[66Overlander]

Originally Posted by john celano

Now that some time has past - do you still like towing your 25' with the H2? I'm consisdering buying a 06 SafariSS '25 and doing this same pairing. I just posted a question about this topic on another thread. Are the weights significantly different on your A/S as compared to the newer ones?

We LOVE the H2 as our tow vehicle. While it may not have the same tow rating as the 3/4-ton Suburban, it does just fine for our current 25' Sovereign which is around 5000lbs. empty and 6000 lbs. ready for the road with a full water tank (less if we don't fill the tank). It has done fine thru the flats and rolling hills, but we haven't been near mountains with it yet. Without looking up the numbers on the Airstream web site, I'd guess a current 25' Safari is near or slightly heavier than our trailer, but likely still within the ratings of the H2. A new 25' Classic would be too heavy.

I'll admit not having much towing experience with other tow vehicles, but can't imagine them to be much better (other than some will pull a larger heavier trailer). There is absolutely no sway with this set up. I am convinced that I don't even need sway control, although I always use it at highway speeds - first a Reese Dual Cam setup with our 1st trailer and now just a friction bar with the current trailer. I attribute this to the heavy weight of the H2 and more importantly to the very short rear axle to hitch dimension.

If you go this route, you will have to buy the longest drop hitch shank you can get (I think ours is listed as an 8" drop). That almost gets the trailer level (the front is about 1-2" high). If we didn't have the air suspension which pumps the rear back up after the trailer as hitched up we'd probably be about level with a little squat in the rear.

One other thing to think about is the spare tire. H2's from 2003 thru early 2005 had the spare in the rear compartment, but later 2005's and 2006's have the spare mounted on the rear bumper. Ours has the spare in the rear compartment, which means I can open the lift gate with the trailer attached. If you get a new H2, you will get a bumper mounted spare and won't be able to open the liftgate with the trailer attached (if that is important to you), unless you move the spare somewhere else (like back inside or on a roof rack). Of course if you are looking at used H2's you get your choice.

If opening the liftgate with the trailer attached is not an issue for you, all you may need to consider is whether you'll need a longer hitch shank to move the ball out from below the tire so that the LP tanks or tongue jack doesn't hit the tire during tight turns. I do not frankly know if this is an issue, it's just one possible concern I had for if/when we update our tow vehicle (I'd strongly consider the H2 again).

Good luck wioth your decision.

[HHP]

Greetings H2 owners!

I own a 2005 H2, and we are in the works for a new 2006 23' Safari LS. 5600 GVWR.

I wanted the 19' but the wife wants the 23'.

Do you think I will be ok with the 122.8 wheel base? I wonder now....

Thanks,

Hart

[Silvertwinkie]

You can safely tow in "D" on a Hummer or any other GM product that has Tow/Haul. The only reason to drive in 3rd with tow haul might be when going up a grade, but other than that, tow/haul modifies the shift patterns and I believe locks the torque converter at a different location, which is one of the main reasons the trans heats up (an unlocked torque converter). By going into 3rd you increase RPMs, which would lock the converter, which tow/haul I believe already does for you..... I've towed in overdrive in our Suburban 6.0L since there is only one "D" with tow/haul mode engaged and have been very pleased. The 3/4 ton has a trans temp gauge and never been to 200 yet, even at significant grade, though on the grade, I did have it in 2nd as it was a very SIGNIFICANT grade I hauled the loaded Safari up. The higher RPM yielded more HP which I was looking to tap into, but I still had tow/haul engaged too.

Not sure if it's just me, but that trailer in the pictures does not look level. If it were me, I would see if adjusting the weight bars can get it better leveled, though I know that the H2 being a bit higher, it may just be that a longer draw bar is what is needed. Just an observation.

[66Overlander]

Silvertwinkie,
If you are refering to my photo, the trailer is as low as I could get it with the longest draw bar available without having a custom hitch made. While I no longer have that trailer, I have a newer one with a similar attitude. I've had it across the scales and the front axle is slightly less weighted than the rear, but both are well withing spec. What is you concern with the levelness of the trailer? If it's sway that is no issue. If it's running the fridge while underway, how far out of level do you consider too far?

And in my case, weight bars don't matter one bit for trailer attitude, because the air suspension will pump the H2 rear back up to level no matter what weight is added at the hitch. However, I do use weight bars to keep the tongue weight within limits and transfer some weight to the front axle. GM says they must be used if the tongue weight is over 500 lbs.

Finally, I only tow in 3rd Tow/Haul with the H2. The larger tires on the H2 result in a higher effective drive ratio that for your Suburban. Plus your 3/4-ton Suburban gets the 4L80 transmission. The H2 gets the 4L65 transmission which is a lighter duty model (but more HD than the 4L60 used in the Tahoe). I figure a little gas mileage (10mpg @ 60mph vs. 11 or 12mpg @ 60 mph) is a good tradeoff to not risk toasting the transmission although I watch the trans gauge and it's never gotten warm on me yet. I suppose 4th Tow/Haul would be fine if on the absolute flats, but in the H2 it does not take much grade in 4th Tow/Haul to cause the Torque converter to unlock or the trans to downshift to 3rd. I get much less of that in 3rd Tow/Haul. My experience is the result of probably 5000 miles of towing an Airstream with the H2.

[66Overlander]

Originally Posted by HHP

Greetings H2 owners!

I own a 2005 H2, and we are in the works for a new 2006 23' Safari LS. 5600 GVWR.

I wanted the 19' but the wife wants the 23'.

Do you think I will be ok with the 122.8 wheel base? I wonder now....

Thanks,

Hart

I know the "stadard wisdom" is that wheelbase is where it's at. My experience towing 26' and 25' Airstreams suggests that this is not an issue for the H2, even though by that wisdom the H2 wheelbase is too short for a trailer of this length. I have never had one hint of sway with either trailer (although I'll admit I only tow at about 60 mph, so I can't comment on how it handles at the 80 mph that some folks tow).

My opinion as to why the H2 bypasses the traditional wisdom is that it has a very short rear axle to hitch length as compared to just about anything else you can buy (Suburban, Pickup, etc.). This short distance means that any sideways motions the trailer may try to impart on the H2 are "less effective" due to the shorter lever arm their being applied thru. Another contributing factor is that the H2 is heavy, so it takes more force to move it around. Finally, I usually have the tires pumped up in the 45-50psi range (rated at 50 psi), so the sidewalls don't flex much. This may also limit sway, although it probably has nothing to do with wheelbase.

Anyway, the bottomline is that in my opinion an H2 should have no issue pulling a 23' (2' shorter than my trailer) with a 5600lb GVWR (My '85 25' Sovereign has a GVWR of 6800 lbs, but a fully loaded weight of only about 6000 lbs. as we travel), as long as you keep the normal parameters, like tongue weight, within normal ranges.

[85MH325]

I'd have to agree with Joe that the Hummer should be ideal tow vehicle for a trailer under 25'.

Joe, regarding the tongue-high attitude and sway, have you towed the trailer without the dual cam bars? Sway control will mask a variety of problems, although you describe that you've done the 'cure' for most of them especially the tire pressure issues. Still, the transferrence of weight to the rear through the tongue being high is not a good thing. It may not be enough transfer in your case to be an issue, but still, a longer drop on your draw bar may be the way to go, even if you have to have one made. If your dual-cam setup is masking sway for you, you won't know it until you really have a problem. That's probably not the time to figure it out.

Roger

[66Overlander]

Roger,
Thanks for the feedback. I had the dual cam with the the 1st trailer (sold it with the trailer). Now all I have is a friction sway control. I have had the trailer up to maybe 45mph without the friction sway control (around town), but with the weight bars in place. Never any sway.

I did pull the old trailer (lighter tongue weight) without even the weight bars (just around town - again up to at most 45mph) until I could get the hitch adjusted properly to allow use of the weight bars. Again no sway.

I have pulled both trailers at highway speeds (60mph max, except in an occasional "passing" situation) with sway control (dual cam or friction) in place and don't feel passing semi's or cross winds any more than if I was driving the H2 alone (the H2 by itself is affected by these things a little because it has the aerodynamics of a brick). It is rock solid with the Airstream attached.

I would like to understand how having the tongue high could affect sway. I can understand that if it was too high due to too much weight bar, it could do so by removing too much weight from the rear axle. This is definitely not my situation because of the air suspension. When I have the weight bars adjusted to put about 100-200 lbs. of the 600 lbs total tongue weight on the front axle, I acheive a 50-50 front to rear weight distribution on the H2 (I only need to transfer this much and not more, because the H2 is a little front heavy to begin with). Also I'm afraid to transfer more weight at the risk of beating up the trailer with the stiff suspension of the H2.

The only other thing I can think of is that the trailer now turns more on the rear axle than the front. This may make the effective trailer wheelbase feel a bit longer than if the trailer was level. This I suppose might make sway more "likely", but we're probably talking inches of effective wheelbase change - not enough that I think it would make any noticable difference.

Thanks in advance for any further enlightenment you can impart to me on this subject.

[dmac]

The nose high attitude may overlead the trailer's rear axle and tires. After towing a distance try feeling the trailer tire sidewalls with your hand. You will likely discover that the rear tires are much warmer than the front. The overloaded rear tires will wear prematurely, and could blow. You could get a drop bar welded up, or Equal-i-zer brand hitches have up to a 14" drop shank available (see http://www.equalizerhitch.com/produc...tech_specs.php)