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Hi! We recently purchased a 2010 GL 450. I am beginning to learn how unfortunate it is that ours wasn't equipped with the, what I believe originally cost $595, towing package. I didn't do my research and just assumed that a host of towing package options up to the 7500 lb. capacity the GL is rated for would be available. My searches have yielded really nothing aftermarket beyond Class III & 3500 lb/350 TW hitches. Also, my local MB dealership parts department gave me a silly look for even asking if these items were still available to order. So, it appears, unless you guys can lead me somewhere else, that my only viable option for adding a hitch involves acquiring (through eBay or salvage yard, or maybe "For Sale" forum here) a used hitch? This also brings me to another important question, could someone please advise me what exactly is "needed" for towing? In other words, what came with the OEM tow package? I have found some used hitches that include the hitch, rear bumper foam and reinforcement bar. I have also read something about a SAM for, presumably, plug-n-play trailer light plug(s), but don't know and haven't been able to find what, if anything, else (trans/PS coolers) might be needed. Any tips or advice you all could provide to let me know what and where I might best find what I need to set our GL up for towing to the capacity our GL's are capable of towing would be greatly appreciated. Thank you!
The aftermarket has caught up to where a visit to the dealer is certainly not required these days. make sure whatever solution you get talks to the rear signal acquisition module so that the car knows it’s towing.
Don’t worry about wiring in the trailer brake controller you can get a echo Bluetooth plug and one that works just as well and avoid any janky electronic wiring.
As far as the tranny cooler goes I don’t think there was a special one on cars with the factory hitch
Curt has one
https://www.etrailer.com/hitch-2007_Mercedes-Benz_GL-Class.htm
Last edited by Max Blast; Jan 28, 2022 at 07:58 PM.
I'm assuming the Signal Acquisition Module (SAM) is something I need to acquire? That seems to be what I've read. I'll have to look into what that echo Bluetooth plug you mentioned is. As far at the aftermarket, the highest hitch class that I've been able to find is a Curt Class III, but it only has a rating of 3500 lbs/350 TW, so that's not going to work for me (in the long term). I found some thread from a few years back when an aftermarket company named Execuhitch/Invisihitch (I think) was making Class IV hitches for X164s, but after searching for them, it appears they've gone out of business, switched names, but regardless, don't offer that hitch. It seems that the next generation GLs do indeed have some aftermarket options for Class III/IV hitches rated to tow 7500, but I've not had that luck finding them for X164s. Thanks for the info, though.
A new SAM was only needed for the early 06 models. The later 06 and newer models have a newer SAM that have a plug for the trailer wiring. Since you have a 2010, you should already have the updated module. In that case, all you would need is the OEM trailer harness (get the version with the wiring for the trailer brake) and to reprogram the central gateway using STAR/Xentry to enable towing. The rear SAM might need programming too, can't remember. Your 2010 should have the plug in the driver footwell for a trailer brake controller. You might need some additional fuses and relays for the rear fuse box as well.
As for the hitch itself, the best option is to get the OEM one used. Make sure you get the ones with the inserts that goes into the frame rails. This is a good portion of the hitch's strength and how the GL can tow up to 7500 lbs. None of the aftermarket designs utilize the insert and therefore can't handle the full rated capacity.
Here is a picture of an assembly I found on eBay. I will only be towing a boat (or items not needing a brake controller) that has hydraulic surge brake only, not electric over hydraulic. In this case, it appears to have the hitch, bars to attach to the "frame," and the wiring harness plugs. Would you all say this is what I'm describing needing, or have I left something out? https://www.ebay.com/itm/12486942631...Cclp%3A2495737
Last edited by Woody1973; Jan 29, 2022 at 08:36 AM.
Reason: left out link
That does indeed have everything. I've bought from those guys before locally, they're good people.
I would plan on reinforcing that hitch though where the mount meets the tube. Apparently that is an older design that had the welds potentially failing when towing heavy. A good welding shop can do it for about 200 or so. Good information here on hitch variations through the years: https://www.benzworld.org/threads/wo...earch.1904865/
Based on that thread, this should be the stronger design.
Excellent information! Thank you very much for also adding about the weld issue. I’m lucky to work at a place where there are people of all trades, including welders. I also feel easier about you having dealt with the company selling on eBay and speaking positively of them.
Excellent information! Thank you very much for also adding about the weld issue. I’m lucky to work at a place where there are people of all trades, including welders. I also feel easier about you having dealt with the company selling on eBay and speaking positively of them.
The one I posted is from the same seller. In any case, if you have easy access to welders, it shouldn't be much of a concern.
Somehow I missed initially seeing the link with the sturdier squared tubing you posted vs. the one I had. They're the same price, so I've added that to my cart. Ahh the world we live in, as I saw that this was a $595 option when equipped new in 2010 and now it costs more for a used one. Sure beats the (lack of) aftermarket options, though. Again, I appreciate the help and advice.
Update: Tsumi, I went with that hitch you recommended, thanks! Now, to try and find installation instructions...
Last edited by Woody1973; Feb 7, 2022 at 10:01 AM.
Reason: Update
I did install a factory hitch on a ML500. It is a bit of an undertaking .. bumper removal and bumper aluminum reinforced removal . I would stay away from the Sams unit BUT having the factory plug will be nice. I bought my hitch for approx $200 via https://www.car-part.com/mobile/
ok good luck
It's pretty self explanatory once you take everything apart. The tricky part is probably removing the bumper and bumper cover, as there are screws that are hard to access. Once you have that taken out, the inserts go in first before putting the hitch on. You'll remove one of the grommets in order to put the harness through, which has its own grommet already on it. Plug the harness into the rear SAM; there's only one slot that it can go into. Plug the fuse connections into the proper place on the fusebox (you'll probably have to refer to a fusebox diagram for this). Find a ground and put the ground cable on it. Once all that is done and the bumper cover is back on (you may need to cut out something for the hitch to go through), you will need to find someone with STAR/Xentry to program the central gateway and rear SAM for trailer detection. I would bring the trailer to make sure it works as long as there isn't too much hassle.
Slightly off topic but the additional transmission cooler was an option on the tow pack. It has a supplementary cooler which only operates when a certain temperature is reached. It makes it hard (impossible) to completely change transmission fluid as can’t can’t flush it out unless temperature is reached
probably only important if you get contaminated fluid
Slightly off topic but the additional transmission cooler was an option on the tow pack. It has a supplementary cooler which only operates when a certain temperature is reached. It makes it hard (impossible) to completely change transmission fluid as can’t can’t flush it out unless temperature is reached
probably only important if you get contaminated fluid
Source? Everything I've seen points to only one transmission cooler available on our cars, and it was the same cooler for every car.
Thanks for the used parts finder link, I believe I’m going to also attempt to find a donor metal bumper cover bottom trim piece (going to double check my GL for it) but I saw a video of an install on a same gen ML, I believe, that shows it needing some cut out/modification as well as some plastic from the bumper cover. I’ve wondered about a trans cooler too, but have not, until this point, seen much mention of them with regards to towing equipment on GLs. Our previous, less capable, minivan required one, and I generally assumed they were also recommended. Tsumi, that same ML hitch install video I found looks to have what I imagine is a very similar install procedure.
it is also mentioned in the wis in regards to flushing transmission.
if I get the chance I will find the option code
may have been an OZ market option because you live on the surface of the sun; but no such option seen here in the US. Which is weird, it gets hot here too.
may have been an OZ market option because you live on the surface of the sun; but no such option seen here in the US. Which is weird, it gets hot here too.
Yeah. Had the same thoughts. Agree it gets hot there
I went to an Australian online parts website. There are images but no part number.
I went to the option list of the car with the extra cooler and there is NOT a separate code. Will see if I can get a photo
Ours definitely has a separate transmission cooler. There's the transmission cooler that's in the radiator along with the power steering and of course coolant, but there's an additional smaller separate radiator in front of that for the transmission. I know because it was a bear to remove the solid lines going to it while I was replacing the radiator. It didn't look like there was any way it could only be engaged when needed but maybe there was a thermostat inside the cooler or something. I can try grabbing a picture of it later if there's interest.
one photo is back of radiator. Small aluminium I believe normally to transmission but in this case to additional oil cooler. Small hole with rag is to transmission
other photo is of additional cooler. Front view
Rear of radiator view
Looking up through middle hole of front bumper bar under tray. Shining a light on part number of radiator
Ours definitely has a separate transmission cooler. There's the transmission cooler that's in the radiator along with the power steering and of course coolant, but there's an additional smaller separate radiator in front of that for the transmission. I know because it was a bear to remove the solid lines going to it while I was replacing the radiator. It didn't look like there was any way it could only be engaged when needed but maybe there was a thermostat inside the cooler or something. I can try grabbing a picture of it later if there's interest.
It sure looks to me like all the trans fluid goes through the supplementary cooler.
What a gimmicky design. And what's more, it looks like the AC condenser is smaller to make room for the cooler.
It just registered that the power steering fluid "cooler" is on the hot side of the radiator. What in heaven's name is the point of that.
It sure looks to me like all the trans fluid goes through the supplementary cooler.
I bet the H-shaped block has a thermostatic bypass inside it. Otherwise I can't think of a good reason to have such a big block, just to have fittings to hold the tubes.
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