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hartusi · 06-24-2009, 09:22 PM

Having recently acquired a Safari 28W I have come to find out that the factory receiver on the Mercedes GL is inadequate for towing my AS. Does anyone have recommendations on reinforcing the receiver?

wkerfoot · 06-24-2009, 09:30 PM

Quote:

Originally Posted by hartusi

Having recently acquired a Safari 28W I have come to find out that the factory receiver on the Mercedes GL is inadequate for towing my AS. Does anyone have recommendations on reinforcing the receiver?

Talk to Rich Luhr, he just went through that issue.

Bill

Wayne&Sam · 06-25-2009, 04:43 AM

Inadequate because of....?

Silvertwinkie · 06-25-2009, 06:31 AM

Quote:

Originally Posted by Wayne&Sam

Inadequate because of....?

Well for starters the SUV is rated with about a 7500lb tow capacity. 10% of that would be hitch weight in the form of about 750lbs. I can tell you first hand that is a conservative number given my exp. I would believe actual hitch weight may be closer to 900lbs for the trailer that is being specified in the question. With the 28' trailer fully loaded, and the truck carrying passengers, fuel and any cargo, will most likely put it over it's rating, let alone the wheel base being WAY too short for a 28' trailer. The hitch is a moot point IMHO based on the avail info I've come across.

My recommendation on reinforcing the receiver is to get a different tow vehicle. You don't reinforce these things. They are specifically rated and you can't modify what's there. You might replace the entire hitch, which some do on other trucks, but in your case, the hitch is only one part of the overall problem. Remember, it may be an alum trailer, but it is still about 3.5 tons behind you. That's not a small amount of weight to be playing around with or trying to cut a corner to fit a round peg in a square hole. Just my opinion. I am sure folks do it, and you'll find many that say, I've had no problems, but I can assure you that doing things that are not orthodox or exceeding manufactures specs can lead to serious injury, death of you, your passengers or the public around you. There is also a certain liability involved should something go south. I tow a trailer with a bit over 3 tons of weight with a truck that is rated to tow well over 4.5 tons. I still am very cautious when I tow, even with the right hitch, wheelbase, etc. Towing my rig in the mountains works wonderfully, but I can't see even with my smaller trailer having less than what I have now, but to each their own.

overlander63 · 06-25-2009, 08:11 AM

Quote:

Originally Posted by hartusi

Having recently acquired a Safari 28W I have come to find out that the factory receiver on the Mercedes GL is inadequate for towing my AS. Does anyone have recommendations on reinforcing the receiver?

Go to a welding/ hitch shop, and tell them what you need. They should be able to remove the tube part of the hitch and put in a square tube in its place. That, along with some selective reinforcements, should help immensely. You can also call Can-Am RV in Ontario (andrewt here on the forums), they can give you further info, IIRC one of their employees tows with a GL.

hartusi · 06-25-2009, 10:51 AM

Inadequate due to factory rating of 600# tongue weight rating and 28W lsited tongue weight of 830#. I intend to install a Propride P3 hitch and could distribute weight in the trailer to reduce tongue weight to 600# and shouldn't have to worry about sway but I've read on Airstream Life Man In The Maze » Blog Archive » 2009 Mercedes Benz GL320 aobut one individuals experinece with failed welds on the factory receiver so I'm not comfortable with just adjusting the tongue weight through weight distribution in the trailer.

hartusi · 06-25-2009, 10:53 AM

Thanks for the response, how do I contact Rich Luhr?

wkerfoot · 06-25-2009, 10:56 AM

Quote:

Originally Posted by hartusi

Thanks for the response, how do I contact Rich Luhr?

There is a contact us link on the first page of the Airstream Life site.

Bill

CanoeStream · 06-25-2009, 11:06 AM

Quote:

Originally Posted by hartusi

... so I'm not comfortable with just adjusting the tongue weight through weight distribution in the trailer.

2airishuman has posted about taking his 34' Classic to the CAT scales and weighing most every parameter. Weight on the trailer axles was unchanged after weight distribution was engaged (a Hensley in his case). This confirms my normal feeling that lowering tongue weight is not a function of weight distribution. Weight distribution's principal function is to torque the tow vehicle frame (through the hitch

) so that not all the tongue weight is borne on the TV rear axle. Cranking on the TV frame like this transfers some of the load off the rear axle and transfers it to the front axle. Again -- tongue weight remains the same.

Most weight up on the A-frame is carried on the hitch. Figuring basic vectors, very little of propane or weight distribution gear weights are transferred back to the coach axles. So ... 60# of propane and your WD gear mostly are added to the tongue weight. The hitch bar for my Reese weights 40+ pounds all by itself! So if you have a box of kleenex, a pair of socks, flip flops and not much more inside the coach, I'd say you're rarely looking at much under 1000# tongue weight when you're outfitted for camping (assuming the stated 830# base tongue weight).

hartusi · 06-25-2009, 12:01 PM

What I meant by redistributing weight was to physically place more weight behind the tow vehicle axles, in my case the primary weight redistribution would be locating 4 AGM batteries behind the axles to reduce tongue weight as part of a solar installation.

Silvertwinkie · 06-25-2009, 01:21 PM

Quote:

Originally Posted by CanoeStream

Most weight up on the A-frame is carried on the hitch. Figuring basic vectors, very little of propane or weight distribution gear weights are transferred back to the coach axles. So ... 60# of propane and your WD gear mostly are added to the tongue weight. The hitch bar for my Reese weights 40+ pounds all by itself! So if you have a box of kleenex, a pair of socks, flip flops and not much more inside the coach, I'd say you're rarely looking at much under 1000# tongue weight when you're outfitted for camping (assuming the stated 830# base tongue weight).

Bingo! Nailed it. In addition, even if you add a more robust hitch, the truck is going to be subjected to weights and stresses it was never designed to take. That's why the factory only puts this kind of hitch on it in the first place. I am not speaking from the pulpit here, I am speaking from exp. I towed my 25er with a Chevy sedan. It was rated for about 500lbs of hitch weight. I exceeded it, even though the hitch I installed could take, I passed the cars rated capacity by about 400lbs (yes, I bought a hitch weight scale and I was far over the 750lb listed on the Airstream site) and don't think for a second that you won't be too. As Bob pointed out, rarely will you see the listed hitch weights met...more than likely you will far exceed it.

Though clearly it's no Mercedes, my Chevy sedan does have gobs of power. In terms of powertrain power, I could haul 10,00lbs. What I found out after one season is that the small things start to wear out prematurely. You can call Andy at Can-Am till the cows come home, but the reality is that you will be able to move the 28 footer somehow, but then at what cost? Mercedes makes great stuff, but those pesky Germans build it to exact specs. Control arms will eventually fail, bushing will wear quicker and you'll most likely get more frame flex exceeding what the factory suggests.

Again, do as you wish, but be warned what you are considering is not a good idea. If you can afford a Benz and an Airstream, why cheap out on the tow vehicle? Get one that is rated correctly and has the proper wheelbase for the application.

dmac · 06-25-2009, 01:29 PM

this is a disaster-in-waiting... trailer too long, tow car too short... propride adding mass to hitch weight over limit... unibody tow car with insufficient tow capacity... attempts to lighten hitch weight will cause instablity...

get another tow vehicle!

Devoman · 06-25-2009, 03:33 PM

Here is the guy you want to talk to.
Can-Am RV Centre (London, Ontario) â€“ Canadaâ€™s RV dealer for Airstream, Crossroads, DoubleTree, Forest River, Keystone, R-Vision, Nu-Wa, and SunnyBrook.

Road Ruler · 06-25-2009, 06:23 PM

Quote:

Originally Posted by overlander63

Go to a welding/ hitch shop, and tell them what you need.
You can also call Can-Am RV in Ontario (andrewt here on the forums), they can give you further info, IIRC one of their employees tows with a GL.

A welding shop could work but I felt comfortable doing the fabrication myself, reinforcing the receiver/platform on our Mini Van years ago... (shown below). This unit is rock solid and flex free

compared to something like a feeble, factory GM receiver.

Consulting with Andrew T, a towing professional is the best advice. If I recall, it was a relation of Andy who is towing the large Airstream with a GL.

redeagle313 · 06-25-2009, 06:34 PM

Quote:

Originally Posted by wkerfoot

Talk to Rich Luhr, he just went through that issue.

Bill

Rich also had other issues with getting the GL ready to tow their AS. Read his recent comments in his "Man in a Maze" Airstream blog.

vajeep · 06-26-2009, 07:30 AM

But I will say I will follow this thread with great interest. The motor is up to the task, but all the other stuff that makes the tow package work seems to me to be more 1/2 ton vs 3/4 ton in my limited opinion. Are there any other forum members that are using the GL to tow at present? We want to know your thoughts!!