towing a trailer - PeachParts Mercedes-Benz Forum

frontwheel · #1 06-26-2006, 12:40 PM

going from dallas to nashville to pick-up a scooter and vacation and need to rent a trailer. plus i've been wanting one for garage saling. no-one makes a hitch for the car and thinking about getting a bumper hitch. need some tech help

frontwheel · #2 06-26-2006, 12:42 PM

it's a '77 300d

leathermang · #3 06-26-2006, 12:43 PM

There are some great threads in the archives about this...
If you have bumpers designed to ' give' at certain speeds then you may not want to attach to the bumper...

t walgamuth · #4 06-26-2006, 06:56 PM

bumper hitch is out. the shocks wont take the load. you need one that bolts on to the bolts that the shocks mount on and goes up under the floor and attaches up near the back of the axle.

tom w

frontwheel · #5 06-27-2006, 02:37 PM

and that is for a motorcycle trailer? i'm talking about mybe 500lbs at the most.

OMEGAMAN · #6 06-27-2006, 05:17 PM

300TD hitch help

t walgamuth · #7 06-27-2006, 07:27 PM

recently i did a little work for a fellow benz enthusiast. he had a parts car sitting out back with an absolutely beautiful bumper on it. so i said i would take the bumper instead of money. he brought out a 17 mm box end and i got down and unbolted the beautiful bumper and then stood up and grabbed it and yanked straight back. the right side came out fine with the shock attached to the bumper but the left side the bumper just pulled off the shock... the little nibs on the bumper or the bolts had just corroded off.

so i would not attach a hitch to any 123 mb bumper.

unless the mounting system of the bumper has been reengineered.

tom w

gs sparhawk · #8 06-28-2006, 12:17 AM

I built a great hitch for my 300CD. I bolted it between the shock mount to the frame ends. I used a 2"+ angle to span between the mounts and welded a 2" receiver to it just under the bumper. I welded an additional strap up between the trunk back and the rear body panel and bolted through to the inside of the rear trunk with a large backing plate on the inside of the trunk to spread the load. It has served me very well over the years hauling a 2000lb. sailboat cross country. No connection to the bumper at all. It is necessary to cut a half circle out of the angle at the bumper shock mount so the shocks can still recess into the frame when mounted. Mark and drill holes for the mounting bolts and position it between the shock flange and the frame. I was able to use the original bolts and parts cost just a little. Most DIY guys may not have a welder but the little welding required shouldn't cost much either. Enjoy. Might want to make sure that tongue weight doesn't get too much and put the nose in the air. After all, you've got a paltry diesel and not a snooty new gasser. Humility is a virtue. BTW, braking never was a problem and that old smoker just dug in a grunted mile after mile. Must be over 300M on her by now and she keeps asking for more. I think she thrives on work.

t walgamuth · #9 06-28-2006, 07:09 AM

now that sounds good. even better would be to add a strut that goes forward and attaches up by the axle to keepit all from flexing in the back. the more leverage the better.

tom w

gs sparhawk · #10 06-28-2006, 10:01 AM

I agree. However, at the time I didn't think it necessary to do that. Since, I have felt that I need to increase rigidity and strength by doing as you suggest or some other improvement to reduce flex. This makes a very adaquate hitch and not very complicated. Also, the receiver, neatlly tucked up under the bumper, painted a flat black, doesn't appear so evident or obtrusive at all.

leathermang · #11 06-28-2006, 10:24 AM

W123 Factory Trailer Hitch

abbamovers · #12 06-28-2006, 11:33 AM

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I built the same type of hitch as gs sparhawk although I did add 2 strut bars to keep it real rigid.
Mine is real beefy as I used a 5 foot long 5 inch by 3 inch , 1/4 inch thick angle iron as the base and beefed that up with 3 strips of 1/4 metal to keep the angled iron from flexing . ( see pics )
The receiver is 2" x 2" internal by 5 inches long and sourced at a metal supermarket for about $ 5.00.
I got a ball and hitch and used that as a template to drill my receiver pin.
The 5 foot long angle iron will have to be angled a bit as the bumper mounts are not 100% flat.
This is good, since I used the angled opening for blasting in a ton of weld to the receiver .
I measured in the middle of the angle iron and hacksawed the 3 inch ledge to the 5 inch upright. Then I cold bent it a few degree and placed it on the car until I got a good match. Then I clamped on the receiver in the middle and lined it up and tack welded it off the car for the final big weld blast to fill in the " V " .
Next I added the 3 cross braces to make it super ridgid.
I next made up the strut bars 33 inches long from angle iron sourced from old bed rails and bolted this to the hitch and an oblong hole under the frame rail near the wheel. I used a homemade oblong 5/8-NC bolt, the oblong tang welded to the head for the strut to frame rail attatch point and then drilled a matching hole to the hitch. I had to use a 1 inch spacer as I needed a little clearance.
After I setup the bumper with homemade stand off nuts and setup the wiring for a 6 wire trailer.
With this setup I can haul a lot of weight as I use the 6 bumper attach bolts and the strut bars to keep it from ripping apart.
The previous owner had used the bumper to mount a hitch and the bumper broke apart at the mounting.
From the look of the bumper it looks like it is cast metal ( aluminum ? )and not pressed steel which makes it more weaker to add a hitch to.
I hope the pics show more info, I can also add a crude dimensions drawing but
most pics exceed the 65kb size.

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