GL 350 as tow vehicle

[jennian]

Does anyone have experience towing an international 27FB with a 2014 mercedes GL350?
And if so what hitch, weight distribution, anti sway and brake controller would you recommend?
Thanks

[Road Ruler]

No experience with an International 27FB / 2014 mercedes GL350 but wish that rig was parked in my driveway. You might also check into whether the Merc needs the receiver reinforced* in order to transfer weight efficiently.

*Note Can Am mod.

[ghaynes755]

Not going to be terribly helpful but while I was at Jackson Center there was a 30ft Excella next to me being towed with an ML350 CDI. He had a Hensley hitch on it. Hitch setup done by CanAm. Totally reinforced to the body of the ML. If you go this route run, don't walk, up to Canada to get the hitch work done.

Also note that you won't be able to load four folks into the ML. The owner said they are maxed out with just the two of them and the dog. Nothing else goes in the ML. But it pulls fine, at least east of the Rockies.

[switz]

In early October 2012, I took my 2007 ML320 CDI from Phoenix to CanAm to have the hitch receiver reinforced. See photo of their work under my "images" link below the avatar. Since I had my Hensley hitch stinger with me, they trimmed about 5" off the tow vehicle side and drilled a new lock pin hole. They they slightly bent the 2" bar downward to preload the weight distribution bars.

A week after my return to Phoenix, I drove to Los Angles (end of October 2012 time frame with cooler air) and hooked up to the brand new and empty 2013 25FB International Serenity. The Airstream literature tongue weight of 833 pounds was actually 1,150 pounds with the Hensley hitch head installed. We set the Hensley at a 3" elevation on the screw jacks. Then we got the Tekonsha Prodigy RF wireless trailer brake controller to operate properly. The propane tanks and fresh water tanks were full as I left for Phoenix driving my first ever RV trailer behind the car.

I had a major tire problem from a screw in the right rear about 40 miles out. The donut spare had to go on the right front and the right front had to go on the right rear. I had never unhitched before so the AAA roadside guy and I managed to bend the jack screw so it would not fully retract. I took the trailer to his home and detached to return back to LA for a CostCo tire repair. Four hours later, in the dark and by myself, I managed to get hitched to the Hensley and continued the journey towards Phoenix at 55 mph (the posted speed limit for towing in California). I started up the steep incline on I-10 East of Palm Springs and toggled the gears down to finally 5th at around 2,200 rpm. No heat or straining issues.

As I passed into Arizona, I maintained 55 mph while the trucks picked up their pace to the 75 mph posted speed limit (plus five or ten). I could feel the bow wave as they came up behind me but the Hensley kept everything in alignment. I got to the East side of Phoenix around 4:30am.

A few days later I took the rig across the local CAT scales configured as I drove the rig home. Even with a full diesel fuel tank, all the Mercedes axle ratings and GVW numbers were okay. I then installed the 15" Michelin LTX (P) 235/75R15 XL tires to replace the stock GYM ST225/75R15D tires.

A few days later, my wife and I (plus a 40 pound air compressor in the back of the car) took the fully camping ready loaded 25FB to the CAT scales. The tongue weight was now 1,175 pounds. The 25FB weighed about 6,975 pounds out of it's 7,300 pounds GVW rating. There were a few shallow hills to climb and the drive train was groaning in 7th gear. The Cat scales reported that the front axle was overloaded and we had exceeded the car's GVW rating.

The Mercedes was retired from this towing job and a 2012 Dodge Ram 2500HD diesel took over the job. The 25FB was later traded in on a 2014 31' Classic with a GVW of 10,000 pounds. That truck and trailer combination is a good marriage.

We recently (July 2015) acquired a new 2015 23D International Serenity. I installed the Hensley hitch from the 25FB and put 15" Michelin LTX (P) 235/75R15 XL tires and 15" SenDel T03-56545T wheels on the 23D replacing the stock 14" equipment. That elevated the 23D to the same level as the 25FB, so the 3" height for the Hensley screw jacks was appropriate. I drove through the Allegheny Mountains getting to Niagra Falls to enter Canada. The ML did a great job handling this much lighter trailer that has a GVW of 6,000 pounds

I towed the 23D from the East Coast to CanAm where they tack welded the Hensley to the trailer and made a few other tweaks to the hitch system. I then drove through Indiana where I crossed the CAT scales and the numbers were all okay on the Mercedes ratings. Since the engine had worked much harder towing a U-Haul to the east coast from Phoenix (with the tires and gear for the new trailer) and then continued onwards with the 23D, I did stop at a Mercedes dealership in Indianapolis (where I picked up the car new in October of 2006) to get some more oil as the level was a quart low. (my service interval is 5,000 miles for oil changes since new and have over 135,000 miles on it now).

By the time I got to Paradise, TX, where the modifications to the trailer are taking place, I had driven about 2,000 miles with the 23D in tow. This is a much better fit for my car.

More will be revealed at the end of September when I use the Mercedes to pick the 23D up from it's extensive modifications and cross the CAT scales while towing it to Phoenix .

The 27FB/28 models have a GVW of 7,600 pounds. The 27FB has an Airstream literature tongue weight of 791 pounds while the 28 has a 976 pound tongue weight. These numbers are lower than the real numbers with a hitch installed.

The newer ML350 diesels prior to 2015 had the 3.0 liter V6 with a hotter chip than is in my ML320 3.0L V6 and had a 7,200 pound tow rating in the US. The hitch receiver is not rated for the tongue weights listed above with weight distribution hitches unless modified like at CanAm.

The 4 cylinder 2.1 Liter dual turbo diesel is the only diesel option on the 2016 GLE (as the ML class is now called) and is limited to towing 6,600 pounds. That is not the appropriate vehicle for towing the wide body Airstreams (25' and longer). That is too small an engine for heavy towing.

The 2016 GL 350 still has the 3.0L V6 turbo diesel and a tow rating of 7,600 pounds. I would think a trip to CanAm for hitch modification would be necessary. The payload of there GL is not much more than the ML so there could not be a lot of stuff carried in the car.

[Andrew T]

We have an 08 GL in our fleet that with 100,000 miles on it with no issues. We regularly tow much heavier trailers than Airstreams with it as it handles higher hitch weights more easily.

Interesting on the GL the Rear axle capacity is increased 500 pounds when towing as long as your speed is under 100 KPH or 62 MPH. The components are all identical to the ML.

In this picture we are testing electronic sway control using the GL and a tall gangly box trailer. Even with the ESC turned off it was amazing how you could toss this big monster around and yet have complete control in the GL.

Depending on what you plan to carry in the GL you might want to modify the 27FB slightly to reduce the hitch weight. We had one in the shop this week that was 1080 loaded for travel. We upgraded to Michelins removed the spare and carrier (Since you'll never get a flat and can run on 3 wheels with Michelins) we could have also relocated the batteries but the spare removal was all we needed for this customer. With the hitch strengthened and the proper set up the GL will easily carry the 1080 but not if you are also going to have 6 people in it etc.

Andrew T

[AdamG01]

Just upgraded my TV for my 2011 27FB Classic from a 2009 GL320 to a 2015 GL350. What an improvement! The GL350 is very smooth starting up, pulls most hills with ease, and has a very smooth, comfortable ride when towing. I use a ProPride hitch and a Tekonsha Prodigy RF brake controller (avoids drilling holes in the beautiful dashboard of the GL). I have never had an issue with this brake controller.

[jmcarter]

2013 GL 350 pulling a 28 International. ProPride does great for sway control and transferring weight forward. Had Andy's team reinforce my hitch but he indicated the earlier X164 chassis and ML's are the models in particular need of reinforcement. Also use the Prodigy RF and am extremely happy with that as well. Believe the key is in the hitch setup...our hitch/AS is in storage currently but if you go this direction I can snap some pics for you. Also, search GL350 and you'll see others besides AdamG and myself who went this direction.

BTW, the newer generation of GL's have more torque and better ride quality. Only watch item would be to service the transmission by the "severe service" intervals and of course invest in the extended warranty but think that's advised with any of the new tech laden vehicles.

[m.hony]

I also ran into a man towing a 28' with a Mercedes GL while at Jackosn Center. He lived in Ohio or Pennsylvania, but bought his trailer out west somewhere and towed it back home.

[jennian]

Would the hitch receiver on the 2014 gl350 need to be reinforced?

[switz]

Cheap insurance to get it reinforced over a body/frame repair

[Armadillo]

Very interesting thread. I am new to all this and have tons of questions. I have inherited my Dad's 27 ft. , 1970 Overlander and in the process of having it restored. I think the empty weight of the trailer is 4575 pounds. I suspect the weight of the trailer after renovation may be increased and when fully loaded for traveling could be closer to 6000 pounds. i have a 2007 Mercedes GL450 with 106,000 miles on it which I used to tow the empty trailer approximately 1500 miles to its restoration shop. The GL450 manual states it has a max tow weight of 7,500 pounds (and will support a max tongue weight of 600 pounds). I have a "Eaz lift" hitch with sway control and weight distribution (rated for max 600 pounds tongue weight and max 10,000 pound trailer weight).

Questions:
1. Is the 2007 GL450 Mercedes a good Tow Vehicle for one or more long cross country trips?
2. Does the hitch need to be reinforced?
3. Should I have a "transmission cooler" installed (not sure what it is?)?
4. Recommendation for brand of Towing Mirrors?

[switz]

Mercedes hitch was not designed for weight distribution forces so re-inforcement is a wise choice for safety.

I am towing a narrow body 2015 23D with my 2007 ML320 CDI so used the Repusel universal tow mirror Luxmax, flat glass, anti-glare blue $146 + 4.49 freight at Amazon. They are made in Holland. They require some effort to attach snugly to the ML320 mirrors and stay aligned even when mirrors auto fold in when engine is shut off and doors are locked.

Gas engine will use more fuel so range between fuel stops will be short. I see 12.5 to 14.5 mpg depending on the terrain with the 3.0L diesel. I am based in Phoenix, so have mountain climbs to get away to the North.

Gas may be sub 10 mpg in the mountains.

[switz]

After the modifications are done, load up the fresh water tank and propane tanks and get an accurate tongue weight as well as the new base weight before all of your stuff goes inside. The goal is a minimum of 10% of the trailers loaded weight or GVW which should be higher. The maximum is typically around 15%. The modification shop should be able to get this information for you when they are done.

The big truck stops usually have CAT scales you can cross hitched to getthe combination weight and then drop the trailer and cross the scales again. The first pass gives the loaded front axleweight, the rear axle weight and the trailer axle weight(s). The second pass of the tow vehicle only will then show how much weight is being added to the front axle by the weight distribution hithch and how much weight is on the reart axle. The difference between the two total weights is the traikler's weight.

Payclose attention to the front axle'a gawr rating. with only two peole in my ML front seats, that number is nearly maxed out.