Splaktar

The manual for MY 2024 has no relevant information for selecting a trailer hitch.

https://mbworld.org/forums/gle-class...on-my2024.html mentions

I have attached the "A 167 310 25 00" picture from my vehicle, which matches the one from the GLE forum and GLS owner posts from the US and Canada.

The 2" seems to correlate with the 2-inch ball rise mentioned above.

The 7.5" seems to be the distance from the center of the pin to the center of the ball. Is there a name for this? Is this the ball mount length?

What is the 2.75"?

What hitch ball setup do you use? Do you recommend it?

jkaetz

You're overthinking. Match the ball size to your trailer. 2" is pretty common. Then select a hitch that has enough load rating for your trailer and positions the ball at the proper height. Our W164 needs a 4" raise (or 6" drop) hitch for our boat trailer to ride properly. The 167 hitch seems to be equally low so I expect a similar need for it.


The diagram is likely laying out the recommended limits for the ball position. Center of the ball no more than 7.5" from the back of the hitch pin. 2" raise or 2.75" drop from the top of the hitch receiver. As noted using the 4" raise with our W164 was significantly better than the lower ball position with our trailer. Yours might be different. The height of the ball will also have some impact on the tongue weight. Higher = less and lower = more. Try one and see how everything feels stability wise and then adjust if you think it needs it.

Splaktar

For starters, I would like to rent a U-Haul 6x12' covered trailer. They offer a 2" ball setup for a 2" hitch receiver for $30. But I don't think that it has the 2" rise. It has a limit of 7,500 lbs. Is this fine to use or do I need to get a hitch ball setup from somewhere like etrailer?

They also offer a 7-pin to 4-pin converter to work with their trailers that have surge brakes and don't need a brake controller. It's $15.

jkaetz

The 7 -> 4 pin adapters are a standard thing you can get anywhere and certainly something you'll want to keep in the rig. Amazon has a few for < $10.

They're likely selling the common 2" drop or 3/4" rise hitch. This will likely also be too low for the GLS receiver.

You'll likely want a 2" - 4" rise. These will be sold as 4" or 6" drop hitches. You'll just want to flip it over.


Don't know how heavy you're planning to load it but I estimate our boat, trailer (surge brakes), and boat cargo to be around 5500 when fully loaded. Even with cargo and people in the ML we never had any issues. I did raise the rear tires to the recommended max load PSI vs the normal PSI. We even had an instance where the trailer brakes were failing but the ML's brakes never complained. Given the GLS and 167 platform should have improved over our 164 ML I can't imagine you'll have any trouble.

We also use a locking hitch pin, but don't leave it in when you're not using it or it'll likely never come unlocked again. Granted I think most of them will break with a good whack from a motivated thief so as with most things they keep honest people honest.

Splaktar

Thank you. The 8.25" or 9.25" length won't be an issue with the hitch that says 7.5"?

Is that a minimum or maximum length?

mikapen

The hitch, and therefore the car itself, must be de-rated because of the greater leverage a trailer exerts with the longer "lever arm."
For best stability, it's best to stay under the 7.5", and the car's ability to control the trailer increases even more with a shorter ball mount.

In short, Shorter is Better. Is there a reason you want a longer ball mount?

mikapen

While those Amazon offerings would fit the receiver, they don't give the distance from the center of hitch pin hole to center of ball hole. That's a critical length to consider, and I'd recommend that you shop at eTrailer.com for better information, and humans to talk to to assemble what you need. Competitive pricing.
Here's one that fits the hitch specification label:
https://www.etrailer.com/Trailer-Hit...RT/C45036.html

jkaetz

Because the more drop/rise you need the farther away from the hitch pin you get. I used the recommended hitch (flipped over so it was a 3/4" rise) for years with our ML and never liked the way it handled with our boat. It wasn't out of control, but the trailer bounce would be transferred to the vehicle very prominently. When I switched to the 4" rise hitch the behavior of everything was immediately better no matter the road conditions. I should have switched much sooner. Yes the maximum ratings may be lower but I'm not towing the maximums either. This is towing on narrow two lane roads as well as 70+ mph interstate.


Some more numbers, U-haul recommends an 18" trailer height for their trailers. The top of the ML hitch is 14" and I suspect this is the same for the GLS (ours isn't home for me to measure at the moment). This would mean you still need a 4" rise to get to the recommended 18".
https://www.uhaul.com/Tips/Trailer-H...ur-Hitch-5227/

mikapen

Yes, the ball height should match the trailer tongue height on a level trailer.
It's important that any trailer be level or it will tend to submarine if low, or rise up if higher than the ball, and generally provide less control over the trailer. As you found out.

I'll bet you can find the correct rise without going longer.
I'll go measure my hitch and see if e-Trailer lists a suitable one. After the playoffs....

Splaktar

I just went out to measure (long walk) and forgot my keys (so I couldn't put it in normal height mode). I was able to measure that it was 14" to the top of the hitch receiver from the ground. It was parked in lowered entry/exit mode (-2), which is 1" lower than normal. So it looks like I'm at 15" and need a rise of 3", potentially 4", if I want it to be at 18" with load on it.

It's unfortunate that all of the ball mounts I find are designed to lower first, then the flipped-over rise is some variable fraction of the lowering distance.

Does anyone recommend the more expensive ball mounts that have adjustable ball height (and even two ball sizes)?

mikapen

I also went out and verified my ball mount at 14 in.
You said that U-Haul recommends an 18-in tongue height, but everything I see with a 4-in rise is either really long or another compromise.

If you/they would accept 1 in lower, here's a hitch from e-trailer that should work for you:
https://www.etrailer.com/Trailer-Hit...er/989892.html

Generally speaking, tongue down is better than tongue up if you have to make a choice.

Regarding my comment about having to de-rate the hitch if it's longer than the 7 1/2 in (which the above hitch is not), it's an incremental thing. Like adjusting your tire pressures to the correct inflation for towing.
Every little bit helps.

I'm facing the same thing, getting ready to rent an enclosed trailer.

Those adjustable ball mounts are awkward and clunky, with another high torque set of bolts that I'd try to avoid.

I'm not fully decided, but I think I'm going to settle on one I linked above.
(I have a half a dozen ball mounts, for two different cars and three trailers, ball sizes 1 7/8 to 2 5/16. I don't want to be loosening and reapplying 250 ft lb of torque and a new spring washer every time I change trailers.)

jkaetz

When I finally decided to change hitches I did actually try the 4"/2.75" rise. It improved the situation but didn't fully resolve it until I went to the 6"/4.75" rise that things really settled down. This makes sense as the trailer was the most level with that height.

That said the ML does not have airmatic, the 2.75" rise might be enough combined with airmatic's load leveling. It's probably going to be a case where you'll have to try both and see which one works better for you. It'll likely be this summer before I can put the boat behind our GLS and see how it behaves.

jkaetz

@Splaktar https://mbworld.org/forums/gle-class...orque-abc.html

Splaktar

Thank you for sharing. I hope that you have a great time at the lake!

I am not sure why your new thread is in the GLE forum though 😇

Dynamicpulse

I'm guessing the OP has a solution already, but just in case it may help others, this is what we tow with. You can position the ball mount for a drop or rise.

mikapen

Picked up my 6x12 U-Haul today. Here are my measurements and thoughts (167 GLE but should be the same as a GLS).
I flipped a Reese hitch, so rise is now 3.5". Pin to ball center 10.5". Ball height 17.5" in Comfort setting. I believe cars maintain the Comfort height at all speeds when your 7-pin is connected.




It's a little out of spec, but well within capacity with the minor de-ratings necessary by the out-of-spec measurements.
The trailer is 4,000 lb gvw with 400 lb tongue weight.
I intend to put more tongue weight than the minimum - I'll aim for 600 lb.

As an aside, I was VERY pleased to see the tires are Carlisle Radial Trail HD, which has an 82 mph speed rating and plenty of capacity. The other acceptable trailer tire to me is a Goodyear Endurance load range D.
Most trailer tires are rated at 55 mph top speed, based on their inability to shed heat at speed. Carlisle and Goodyear (in that order) developed compounds and constructions that allow better heat dissipation and therefore the higher speed rating.
We're in record heat, and I'd stick to the 55 mph rating if that's all the tires gave me. But with the Carlisle's, I can Cruise at a reasonable speed. Yay.