M-b gl450

[phm31750]

We have a 2013 M-B GL450 and decided on a 19' Airstream. When the vehicle was purchased we had the M-B dealer install the M-B hitch. We know we will need to have a brake controller installed. We don't know enough to know which one will give us most satisfactory service.
AND, our tow vehicle has as standard equipment M-B's proprietary Electronic Stability Program which includes "Trailer Stability Assistance". The vehicle also has the standard equipment "Airmatic Suspension" which equalizes front/rear
ride heights, compensating for increased cargo or load. Do we need a weight distributing or equalizing hitch or whatever I should be naming it?

[idroba]

Yes, you need a weight distributing hitch, even with the air suspension. The system you have is the same, or very similar to the one I have on my Jeep Grand Cherokee. It will keep the vehicle level, but will not move some of the hitch weight of the trailer to the front steer axle, which is necessary. Most WD hitches also have some kind of sway control built in to reduce or eliminate sway from the get go. The electronic sway control you have is also on my GC, but it works only after the fact and is not a substitute for a good system in the hitch to begin with. The electronic system is a good addition, but not a substitute for hitch sway control.

Your 19' is a small and stable trailer to begin with, but still needs a good WD hitch.

[Wayward]

I am not sure there is a whole lot of difference in brake controllers so long as you go with a brand name like Prodigy or Tekonsha. You will probably want a MB harness adapter that mates to the unit. Some adapters are ready to plug in the vehicle, others are just pigtails. Your mechanic will figure that out.

They are pretty much setup and forget, but you want to be able to glance over and check the setting or test the manual override now and then. They are about the size of a radar detector. Give some thought as to where you want it mounted. e.g convenient access to adjust or override , but not obtrusive.

They are not exactly pretty and Mercedes certainly thinks through every square inch of their cockpit with design and function, so you may want a controller that is easy to remove/replace when not towing.

With 500lbs tongue weight, a short overhang and air suspension, I'd just hook it up and take a careful test drive before choosing a weight distribution and/or anti-sway - but most folks here would give the same advice on a weight distribution system as IDROBA did.

[murreywalker]

I towed my old 23FB with a MB GL 450. Had/have a Reese Dual Cam WDH with a Reese Sway bar. I towed the 23, 40 miles to the dealer without the sway bar hooked up. Never did that again; a gust of wind and you've got issue to contend with.

Like the others say, a WD hitch makes good sense. Also that Sway Bar.

There's a Service Bulletin T-B-31.19/07d. Your mechanic can put that to good use.

Here's a MB forum thread that's also relevant;
trailer brake controller - Mercedes-Benz Forum


Good luck!

[switz]

The easiest to set up is the Tekonsha RfF Prodigy with no direct connection to car wiring harness. The seven pin trailer plug goes into the MB socket but interrupts the brake wires in the black box that mounted on the trailer frame. Hand held device size of a pack of cigarettes plugs into car power in ash tray and sends radio control signals to black box. Worked well with our ML320 diesel and the 25FB international serenity

Used a Hensley hitch with 1,000 pound bars.

[Wayne&Sam]

Towed for years with an ML500 and a 20' Safari using Reese DualCam and a Prodigy. No complaints.

I've replaced the ML with a Dodge Durango (same platform at the GL, minus Airmatic). Again, no complaints.

[rostam]

http://www.benzworld.org/forums/x-16...tallation.html

Here is how I had the controller installed. No interference with knee airbag, No need to drill the dash, and the controller can be removed when not used.

[jmcarter]

Towing our International Serenity 28ft with a 2013 GL350, went with the ProPride simply to move more weight forward and get my axle weights well within limits. Don't think you need the expense and heft of PP but a simple WD/sway control hitch is prudent. For controller I bought a Prodigy RF, mounted the box to the frame, paired it to the MB and was done. Recommend the RF route.

[kellykellyi]

Originally Posted by jmcarter

Towing our International Serenity 28ft with a 2013 GL350, went with the ProPride simply to move more weight forward and get my axle weights well within limits. Don't think you need the expense and heft of PP but a simple WD/sway control hitch is prudent. For controller I bought a Prodigy RF, mounted the box to the frame, paired it to the MB and was done. Recommend the RF route.

I just bought a 25FB and love hearing that someone is towing an AS with similar specs with a MB GL350. I am considering a GL450 as my new tow vehicle. Any modifications made to your TV?

[StokerDoc]

We were informed that our 2014 GL 350 BlueTec has a production date of Feb 26. Hoping for a mid-late Mar delivery. I have been on the fence about brake controllers as I am not interested in cutting or screwing into the dash. The RF system seems like the way to go.

A couple of questions for you, is there a specific position the controller in the vehicle needs to be? Can it sit in any orientation? Have you had issues while driving where it became unpaired with the trailer?

I am very excited about the new TV. Don't get me wrong, our current Tundra is a nice truck as trucks go. We are planning ahead for when we are both retired and will drop to one vehicle that hopefully will do everything for us from groceries, to the odd run to the compost yard, to ferrying a bunch of kids on a field trip for school, to towing our 28ft Serenity, all in comfort with better manoeuvrability and hopefully with a bit better fuel economy.

[rostam]

The only (minor) issue with RF controllers is when you want to tow another trailer -- You need to un-install the module from your trailer's A-frame and install it on the new trailer. RF break controllers are great for when you have a single trailer and multiple tow vehicles -- All TVs can all operate with a single controller.

I put a link above on how I installed a break controller without drilling the dash. Here is a photo.

[rostam]

oops! forgot the photo.

[murreywalker]

Towing, using the MB GL, regardless of engine, needs to be thoroughly thought out, IMO.

I had two GLs, one a diesel, and the other a 450. The GL is designed to handle a hitch weight of 750 lbs. The specs. on the towing rating can be easily Googled.

However, in my opinion, the most significant thing that's constantly overlooked is the toll the longer/heavier Airstreams take on the vehicle's transmission.

That's a reality that I experienced.

[jmcarter]

Our Prodigy RF has come unpaired once. I knew it immediately because the controller display immediately started flashing " n c " (not connected) and I pulled over and repaired it (you still have trailer brakes even if the controller is showing not connected). The hand controller sits anywhere in the console area (frequently it sits in my lap during bad traffic or going down steep grades. The cord just plugs into a 12V outlet and I've included a pic. I'm particularly partial to the diesel 350 because of the great mileage, range and the monster torque is so low in the RPM range that you're always in the sweet spot and downshifts only occur on the steepest grades. You can buy a connector that overcomes the MB not recognizing LED trailer lights which is common with the German SUV's. Be glad to answer any questions on the TV or our setup.




Hadn't heard of any trans issues on the newer MB's beyond software but I got a great deal on an extended warranty and since I'm well within the rated specs I didn't hesitate. 2013 was the first year of the newest X166 GL's so the warranty was more a peace of mind thing.

[StokerDoc]

That's good to know about the RF controller. It seems like a very simple setup that will work well for me. Not drilling or cutting.

I thought I read in these forums that MB fixed the LED trailer light issue. I'll look into it some more.

I am planning a trip to Ontario this summer to visit family and I am going to Cam-Am to have their staff reinforce our hitch and tune the setup. Also a welded shorter shank and any WD adjustments necessary to balance our rig to stay well within any load limits imposed by payload or axle weight ratings. I very confident that 455 lb-ft of torque and 1750 lbs of payload that the GL will be a great match for our trailer and our family needs.

[switz]

On our 25FB, the dealer installed a couple of regular incandescent light bulbs under the bed in the brake circuit and then the 2007 Mercedes ML320 CDI diesel was happy to recognize that a trailer was attached.

[jmcarter]

Originally Posted by switz

On our 25FB, the dealer installed a couple of regular incandescent light bulbs under the bed in the brake circuit and then the 2007 Mercedes ML320 CDI diesel was happy to recognize that a trailer was attached.

This is the same fix that Andy at CanAm advised, unfortunately I had already bought the special connector and sometimes a Dodge truck pulls my trailer and it doesn't have the blinking LED issue. Think your dealer also installed lights in the turn and running light circuits as well...or at least this is what Andy advised.

[Zia]

I purchased 3 outside light fixtures form Inland RV yesterday, planning to install them in all three circuits as recommended by CanAm. Hopefully that will solve the blinking light problem.
I like to thank Andy for sending me the wiring diagram.

[Zia]

Happy to report that after installing the lights in three circuits according to my previous post the blinking has gone away.

[kellykellyi]

I am curious as to why you chose the GL-450 rather than the GL-350?