Trailer hitch receiver for 126 body - PeachParts Mercedes-Benz Forum

The Gears · #1 09-06-2013, 11:08 PM

This is a New Style receiver for the w126 body and different from all others available.
The torque tube is fitted behind the bumper and allows full travel of the bumper on impact. Nothing is fastened to the bumper.
Installs at the three bolts on each side at the bumper install points and two 3/8" bolts into the spare tire well. Installation on an SD is very easy. I have a dozen of these receivers installed on member’s cars now for towing and bike racks. Price $195,00 plus freight. Weight is 30#, ships by Fed X from Blaine ,Washington.
Pic1 There is easy access to the bolts with flat wrench and socket for the other two.
Pic2 Before puling he bumper back remove the mug guards on each side.
Pic3 Rest the bumper on a couple of dairy box's or kitchen chairs then
thread the receiver over the bumper bolts and shove the bumper back in place.
After reinstalling the bumper drill the two 3/8”bolt holes into the spare tire well and
install the two bolts, supplied. Yes, remove the spare before drilling.
Pic4 Ready to ship, no additional packaging required with FedX
Pic5.The receiver is set back under the bumper, a neat look, and behind
the bumper impact collapse point
The bumper will re install tight to the body with no space, the original look.

kerry · #2 09-07-2013, 09:33 AM

Very nice.

Ol' Yeller · #3 09-07-2013, 09:50 AM

Very nice! I've been working on a design for a W123 body and am waiting for some measurements from someone who has a non-bumper mount hitch on their W123 TD. (Euro or Curtis). Please reply to the below thread.

http://www.peachparts.com/shopforum/diesel-discussion/343194-w123-300td-trailer-hitch-question.html

I like that your square tube is hidden by the bumper. How is the receiver attached to the square tube so the bumper doesn't strike that attachment during a rear bumper impact event?

What size is your receiver?

Thanks!

GregMN · #4 09-07-2013, 11:04 AM

Quote:

Originally Posted by The Gears

This is a New Style receiver for the w126 body and different from all others available.

Been there, done that 3 years ago.... http://www.peachparts.com/shopforum/diesel-discussion/288463-w126-trailer-hitch.html

You should be hearing from my patent lawyer shortly...

Not.

Good job. But the receiver looks small. Probably couldn't do this with it: http://www.peachparts.com/shopforum/diesel-discussion/297171-towing-sec-sdl.html

The Gears · #5 09-08-2013, 01:52 PM

I am working on a design for a 1 1/4 receiver for the 123 and TD.
If there is a want for these receivers I would make up a few.
Design would be similar to my SD receiver with the torque tube inside the bumper leaving the bumper free to collapse. Ang a neat looking receiver.

Junkman · #6 09-08-2013, 03:03 PM

All of my stuff uses a 2" receiver. What size is this?

The Gears · #7 09-08-2013, 08:49 PM

Hi Junkman.
The receivers I build for the 126 body are ClassII 1 1/4".
I never went into the larger capacity receivers because I don't think the body has sufficient material strength for heavy towing. Also there is the problem of trani damage from overheating and possibly the engine as well. These are little cars in a big body and just don't have big towing stuff.
The trailer hitch industry has it all figured out to save their ass from liability. Here are the specs for Class II receivers.

Class II Trailer Hitch Receivers:

Designed for light-duty towing
Are rated up to 3,500 lbs GTW and 350 lbs TW
1-1/4" x 1-1/4" receiver hitch opening
Will work with Class I and Class II accessories, such as bike racks, cargo carriers, and tube covers
Requires a Manufacturer-recommended, hitch specific drawbar or ball mount to tow a trailer
A 1/2" pin must be used to secure the ball mount in place.
Drawbars may be included with hitch or sold separately
Available in square and round tube designs.
Will work with hitch balls with 3/4" diameter shank

Ol' Yeller · #8 09-09-2013, 07:34 AM

Hi The,

I agree with you about overloading the transmission and the rear sheet metal, especially with a design that doesn't take advantage of the stiffness of the frame rails. Tongue load is one thing, but the inertia of thousands of pounds is another. As Newton said: F=MA

The advantage of the 2" receiver is the shape. With a 2" receiver, you can get a hitch that will have the proper height for an application. With a 1 1/4" receiver, you're stuck with a fixed height rectangular tube with a ball bolted to it.

Cheers!

The Gears · #9 09-09-2013, 12:46 PM

[QUOTE=Ol' Yeller;3203603]Hi The,

The advantage of the 2" receiver is the shape. With a 2" receiver, you can get a hitch that will have the proper height for an application. With a 1 1/4" receiver, you're stuck with a fixed height rectangular tube with a ball bolted to it.

Back to you Ol' Yeller
The ClassII receiver has the same selection of draw bars as a 2".
The bar can be inserted with the ball tongue up or down and that will provide a 3" variation to height also a bar with a straight tongue will vary the height 1.5"

You mentioned the bars that some manufactures fasten to two the frame box sections to control torque.
The design of their receiver, with the torque tube bellow the mounting plate creates a "hinge" point where the torque tube welds to the plate. But then again are these manufactures trying to build a Class III or four receiver, 2".
My New Style design eliminates this "hinge" point. Also the need for 1/4" material in the mounting plate. In my design I run a single bar forward to the spare wheel well for additional stability. Yes fastening a receiver to tin can be a problem.
John

Junkman · #10 09-09-2013, 01:46 PM

I mainly want a hitch on the SDs for hauling bikes and was hoping to use the same equipment that I currently have. I have different tongues and hitch balls all on 2". Besides, there is enough stuff around that only sees intermittent use and I prefer not adding more that only duplicates existing equipment. Friends racks are mostly 2" also.

The 00 Diesel Ram does the heavy hauling but I'd only need 1 small piece (the adaptor) to go down to 1 1/4" if I ever have a trailer or bike rack that size.

How much trouble is it to make them for a 2" receiver?

GregMN · #11 09-09-2013, 04:15 PM

Quote:

Originally Posted by Junkman

How much trouble is it to make them for a 2" receiver?

No trouble at all.

http://www.peachparts.com/shopforum/attachments/diesel-discussion/109842d1362348223-w126-trailer-hitch-trailer-hitch-pad-w126.pdf

http://www.peachparts.com/shopforum/attachments/diesel-discussion/109843d1362348241-w126-trailer-hitch-trailer-hitch-w126.pdf

The Gears · #12 09-10-2013, 01:44 AM

Quote:

Originally Posted by Junkman

I mainly want a hitch on the SDs for hauling bikes and was hoping to use the same equipment that I currently have. I have different tongues and hitch balls all on 2". Besides, there is enough stuff around that only sees intermittent use and I prefer not adding more that only duplicates existing equipment. Friends racks are mostly 2" also.

The 00 Diesel Ram does the heavy hauling but I'd only need 1 small piece (the adaptor) to go down to 1 1/4" if I ever have a trailer or bike rack that size.

How much trouble is it to make them for a 2" receiver?

Junkman. That is easy enough to do But I won't do it. I have been asked several times. When I sell a receiver that puts me in a possible liable position.
I am retired now but was in the trailer hitch fabricating business for seventeen years back before a receiver came out of a box. Every receiver had to be engineered then installed under the car. After designing and installing many thousands of receivers I know what is safe and what is not.

Ol' Yeller · #13 09-10-2013, 08:09 AM

Hi John,

Thanks for your thoughts and it's great to know that there are many years of experience behind your judgement and design.

For the benefit of us DIYers, could you post some photos of how your receiver tube is hung from the torsion tube? It appears to be flat plate but it's hard to tell from your photos. Is the safety chain/gusset plate part of the same plate or a separate piece?

Here's where my design is. My application is a 4x8" LoadRite utlility trailer that might weight 600 lbs. It has a rated load capacity of 2000 lbs which I doubt that I would ever use/need but if I did, it would be quite local (loam/gravel) and driven as low speed.

I've found that some of the challenges designing a hitch for the W123D is that the bumper mount surface is not flat as it appears to be on the W123TD wagon, and the tailpipe routing. I don't know if it's flat on a W126 sedan. Instead, the mounts are inclined at 4 deg. This is shown in photo 5.

Your two bumper hang plates appear to be bent (braked) 1/4" or 3/16" flat plate. The necessary radius of curvature (3/4"-1"?) of the bend, which can't begin until exiting from beneath the bumper mount, will probably interfere with the tailpipe. There's 3/4" of clearance between the inboard side of my bumper-bolt-hanger (welded joint) and about an inch to the 2x2" square tube wooden mock-up. This is shown in photos 1,2 and 3.

The 2x2" square tube will be butt welded to the sides of the 2" receiver tube. The 2x2" square tube will have welded end-plates with slot holes. The end plate slot holes will attach to the bumper-bolt-hanger slot holes with 1/4" galvanized bolts. These 8 bolts have twice the cross-section area and therefore twice the shear strength of the 1/2" receiver hitch pin. The slots allow for some vertical and fore-aft adjustment as needed. The L shaped plate with the slotted holes that is welded to the bumper-bolt-hangers allows for 2" of bumper movement. The narrow portion of the "L" is 1" which serves to stiffen the bumper bolt hanger.

Given my concern about the clearance between the tailpipe and the hanger/square tube, I picked up a Harbor Freight IR temperature gun. The tailpipe was about 280 deg. after a drive on hot day and on the interstate. This leads me to believe that powdercoat paint would hold up OK. Anyone else make similar measurements?

I'm still waiting for someone to volunteer the dimensions of the 300TD hitch stiffening brace that runs between the bumper-bolt-hanger and the frame rails. From some photos that someone sent me it looks to be about 1/2" x 1" flat stock bent into a "z" shape. Anyone know how long those mount bolts are/how thick the frame rail is?

thanks!