Flat towing a 1983 300SD behind an RV
 

I am looking to find a way to long-distance tow my 300SD behind my RV (a school bus conversion) - and I think I'd like to flat tow it using a tow bar. The driveshaft will be disconnected (I can do this manually) so I'm not concerned about the transmission. I'm trying to work on the cheap (all my money is going toward the bus-motorhome to make it livable).

This is for long-distance travel so it needs to be safe and reliable.

Tow dollies don't seem to make much sense because you have to disconnect the driveshaft anyway. And towing the car backwards (front wheels on the ground) isn't stable above 25mph. A flatbed trailer is nowhere in my price range, not even used.

I just purchased an adjustable tow bar from Harbor Freight:

Tow Bar - Adjustable Tow Bar w/ 5000 Lb. Capacity

http://www.harborfreight.com/media/c...mage_14964.jpg

This does not have any mounting bracket assembly, and since the 300SD does not have a flat steel bumper (like jeeps) I would assume I need to mount it to the frame behind the bumper.

The kit comes with two small brackets for mounting onto a flat bumper, but it also advises to get a separate mounting kit (essentially two L-shaped bars sticking through the bumper) for MOST vehicles.

I've taken a look and it seems that for a permanent solution my best bet is to perhaps cut holes through the bumper on both sides and add some sort of mounting bracket assembly there. You can see what I mean if you download the user manual for this tow bar.

I have access to either 3/16" or 1/4" plating, which I can perhaps mount between the frame and bumper and/or drill several holes with large bolts to secure it to the frame.

The question then is, are there mounting brackets (the type that stick out beyond the bumper) that go between the plate and the tow bar (and where do I get them)? And if so, am I probably going to need to cut through my bumper?

I'm assuming what I need are "tow arms", ie something like:

http://www.etrailer.com/Merchant2/gr...9-5_2_1000.jpg

Or do the ends of the tow bar simply mount directly through the bumper, to the plate? I'm somewhat assuming this makes the tow bar too short and there needs to be pieces sticking out to mount to. Perhaps the lower halves of these tow arms here.

I think you would need to check the legality of towing a heavy car like the SD behind a converted school-bus!
--All the states you intend to travel may have different rules about this.....

It certainly Wouldnt be allowed here in UK!--vehicle (trailer) weight limited to 750Kg I believe here for that sort of thing.....

What are you going to do for braking on what is now in effect a trailer?

Or maybe I should return this Harbor Freight thing and get something brand name that also includes some sort of mounting bracket.

I used a folding towbar from Roadmaster on my Suzuki. Roadmaster sells mounting brackets designed for each specific vehicle. Not sure if they sell them for a 126. You'd have to check their website. I bought the towbar used. It will be a headache disconnecting the driveshaft everytime you want to tow it. Disconnect kits are available. They are not cheap. I decided it was cheaper and easier to tow a 4wd vehicle with a transfer case which permitted towing in neutral than to put a driveshaft disconnect on my 123 wagon. Nothing illegal about flat towing a car in the USA to my knowledge. I didn't use brakes on the Suzuki. I had a retarder on my Wanderlodge and the bus weighed 35k lbs. I didn't notice the Suzuki back there.

I have a tow bar similar to the one pictured. I remove the bumper on a 123 car and bolt adapters onto the stub frame. The stub frame though is not all that strong since it is designed to collapse in a collision.

For a repetitive towing situation behind a motor home I would choose a trailer to put the car on. It can be backed which you cannot do with a tow bar and it has brakes which you won't have with the tow bar. The trailer will cost more, to
be sure but you will have it for any other purpose you might choose and when finished with it you can sell it and get most of your money back.

For me the main advantage with the tow bar is I can drive across the country to pick up a car with no penalty in fuel economy from towing a large trailer
and flat tow home with minimal sacrifice in fuel economy towing behind my 3/4 ton dodge truck.

I mounted the tow bar to the bumper. Look at the 3rd photo on the first post : http://www.peachparts.com/shopforum/diesel-discussion/297171-towing-sec-sdl.html

The mounting hardware on the hitch you got will work. I would just make a larger backing plate for the bolts. I used a bumper from a parts car that I removed the cover and cut shorter to make it easier to transport from home to the car. If you don't mind some holes in the cover, you could permanently mount the hardware to the bumper by cutting out the bumper cover so they mount hard against the inner bumper.

Using a bumper from a parts car is a great idea. However, if you want something a little more permanent (and better looking), you need a "base plate" (something like the tow arms you pictured) that is mounted permanently under the stock bumper with only holes where the tow bar arms stick into. I had a base plate (made by Roadmaster) on my PT Cruiser that worked great. The arms were slotted in such a way that they were put into the sleeves (1 1/2 tube on each side) of the base plate, and turned in towards the center. The tow bar was then connected on the arms with quick disconnect brackets (another Roadmaster item). The best part of this system, is there is only a 1 1/2 tube sticking (about an inch) out from the bumper on each side. The rest of the mounting structure is under the bumper and cover. I still have the base plate and arms (crashed the car years ago), so I could probably get a photo for you if you would like. Come to think of it, these could be fabricated and modified to work on any vehicle (including an MB 126).

Personally, I wouldn't even consider flat towing a unibody vehicle with a tow bar. In a critical situation, (Think an emergency stop on a winding mountain road.) you don't have enough structure to maintain safe control. I know a tow dolly "sounds" redundant, it really isn't due to the frame of the dolly. Also, it would prevent a lot of strain on the steering system. Think twice about having to crawl under the car every time you want to go somewhere. (This will occur on a regular basis while rain is falling.)

The reason Jeeps and Samari are popular for flat towing is due to their frame for connecting a tow bar and the manual transmission.

If you go with the Mercedes, get a tow dolly with brakes. Northern Tool has brake systems you can add to a tow dolly. It is going to cost you more but the difference in safety is well worth it. Believe me, I towed a fifth wheel trailer for years and you will be thankful for the extra safety when a tire decides to separate at 70 mph! I've been there. Remember, we are not talking about just driving from point A to B, we are talking about towing on a regular basis.

If you bolt the towbar to the front bumper attachments it should be strong enough... after all that's what the factory hitches bolt to as well and we know those are strong! The bumper mounts are the strongest part of the car.

But, a dolly with brakes would be nice too. Honestly though... a tow dolly, with brakes, dragging a front wheel drive car around is probably the best bet. Having to diddle with the driveshaft sounds like a huge bother.

-J

The bumper mounts are not that strong. I have pulled out bolts from them. They are designed to crush in an accident, not to attach tow bars to.

They're fine for occasional towing but not in my opinion for repeated towing. A trailer remains your best option for safety and convenience, though it does take space once you arrive at your destination.

Lots of opinions expressed here, but the OP will do what seems best for him based on those opinions (That is what I would do). My opinion is that the front bumper mounting points can be made strong enough to lift the entire car said said mounts if need be. I just had a look under my friends 126 a few minutes ago, and I see no reason why a mount could not be made so that the brackets stick out just below the bumper in the vented part (fascia). It would look much better than having holes drilled in the actual bumper. Again, just my opinion as to how I would do it if I had the need....Rich

Attaching to the bumper is totally inadvisable. The bumpers fall off on their own due to corrosion.

Yeah I'm an idiot, see below:

The only MB we hauled is a 78 240D and it was on a trailer. A Trailer is a much safer way to transport a large vehicle. although I have seen a lot of vehicles towed on a Dolly.

Towing with the rear end on the dolly is more of a safety issue with the majority of the weight now at the far rear. it would be like improper loading a trailer with the majority of the weight to the rear. it will cause a whipping action, then it can upset the towing vehicle and cause a major accident.

Each way to move a vehicle has it`s own set of safety issues to be aware of.

The OP has to weigh out what is best for him to work through, which every way is settled on, just do it safely.

Reading through this thread got me to thinking of this thread.

http://www.peachparts.com/shopforum/general-information/225168-towing-disaster.html


Charlie

I don't believe anyone suggested that the tow bar be fastened to the bumper, so yes, "Attaching to the bumper is totally inadvisable" is agreed.
Attaching a tow bar base plate (home made or otherwise) to the place where the bumper attaches (and more) is the only advisable way. A plate could be made that sandwiches between the bumper shocks and the frame and another separate attachment point made, and that plate welded to the attachment points of the tow bar. I am sure (if it were my car) I could design and fabricate a base plate that would be able to lift the entire weight of the car if need be. I am also sure there are plenty of other people that could do the same or better....Rich

X2 I'd go for a trailer much safer (and also you don't have to arse about with the propshaft)

I am well aware of your skill in metal fabrication (;))....my concern is with the thin sidewalls of the shock tube supports.....on the other hand I have never had the bumper off a 126 so they could be thicker than the 123.....but without serious reinforcement I would take the bet about supporting the car by the bumper mount bolts on a 123.

You're going to have to mount your brackets to the unibody, with re-inforcing plates under the bracket faceplates to tow the MB. It can be done, but would be a lot of work, versus just renting a trailer. I would definitely have brakes on the trailer, unless I was towing with an HD pick up, or 1 ton truck - and even then, I'd prefer trailer brakes.

uuuh--he's towing it with a bus.

All the MB's that I have seen have a tow hook in front, and it can be assumed that it is strong enough to pull the car not under it's own power. Yes it is a non-removable part of the uni-body structure, but it alone could probably hold the entire weight of the car if it had to. If you look at ALL of the base plates manufactured by the well known companies (Roadmaster etc.), you will see that they all use existing mounting points (bumper mounting points primarily)in addition to other mounting points that are perpendicular to the primary mounting points. Sometimes holes have to be drilled for the secondary mounting points. My "point" (is there a limit to how many times a word can be used in a thread?:D) is, no tow bar mounting should rely on only one axis of mounting. If a tow bar had only bolts going fore and aft (for example the bumper shocks), it would be easy to pull them out in an extreme situation. As others have said, bolts and reinforcing plates in addition to the stock mounting bolts and points are very important. From the first post tomas_maly said:
"I am looking to find a way to long-distance tow my 300SD behind my RV (a school bus conversion) - and I think I'd like to flat tow it using a tow bar. The driveshaft will be disconnected (I can do this manually) so I'm not concerned about the transmission. I'm trying to work on the cheap (all my money is going toward the bus-motorhome to make it livable).
This is for long-distance travel so it needs to be safe and reliable.
Tow dollies don't seem to make much sense because you have to disconnect the driveshaft anyway. And towing the car backwards (front wheels on the ground) isn't stable above 25mph. A flatbed trailer is nowhere in my price range, not even used."
It seems to me that he is set on towing his car with a tow bar, so I am offering him MY support for his decision. I am not going to try and talk him out of towing his car any other way (as others are continuing to do). I believe it is the best choice for the least cost, but ONLY if it is done correctly by a competent fabricator. Just running some long bolts through the bumper with big washers is not going to cut it.....Rich

Yes, he probably won't even know it is back there.

Long term I will probably do a tow dolly/quick disconnect or a full sized flatbed trailer, but for right now it's just not in my budget. I will probably only do this at most 4 times in the next year (about 500 miles or less drive) before getting something better.

For now I'd like to consider mounting the tow bar to the front frame somehow.

I've looked from underneath behind the bumper for some strong place to mount, and I really have not found much to be confident in. Perhaps this weekend I will take off the bumper to my parts car (another 300SD) and think about it some more. It has to be mounted to the frame, not just the bumper, and I'm assuming some sort of square tubing needs to protrude out through the fascia of the bumper (and even then there still is the piece connecting the square tube to the tow bar). I am really hesitant to deal with Roadmaster since they quote $400 just for brackets of any kind of car.

For example:

http://www.benzworld.org/forums/atta...icture-013.jpg

This is for a different body, but the framing is similar enough. There is simply no clear place to mount it except having some sort of steel plate to fit over the mount holes for the bumper. Or perhaps something like this:

http://cdn.hitchsource.com/images/rm...ar-bracket.jpg

This might work in the sense of mounting to the side walls of the framing behind the bumper mounts.

A trailer really is the best way to do what you're doing, and they aren't that expensive:

equipment trailer for sale

Car Trailer 18ft electric brakes car hauler

This one is only $1700 and comes with a 1996 Suzuki Esteem that might even run:

96 suzuki+ car trailer combo

Another one for $1600:

car trailer

My predicament is that I'm in between state residences... My license says a NY address but I'm in NJ (intending on going back to Upstate NY). The address in NY is unfortunately not one I'm able to get the mail for (ie a title), so registering a trailer with the NY DMV is not really an option.

If I went the easy route and just rented a UHaul trailer, that would cost me $140+ JUST to tow my car ONCE.

I think New Jersey has a temporary registration for non-residents - where I can buy a vehicle/trailer/etc in NJ and get temp tags to at least use it. For now I really only need to use it once, at least until maybe Thanksgiving. By then I can have all these issues resolved, get a permanent address, etc. I will have to call to find out.

I'm probably best off just returning the tow bar to Harbor Freight and worrying about all this right before I leave. I may or may not want to spend the $1500 for a trailer I'm barely going to use. For the time being I can probably improvise - either I drive my car or drive my motorhome, but not bringing both. The reality is I'm never going too far, at least for now. I'm also unemployed so maybe going with a rental is better and just live without the car for my RV trips.

I still have the Roadmaster base plate from my wrecked PT Cruiser that I would sell for much less than a new one. It has the major components that you would need to fabricate a custom base plate for a 126. I would have to dig it out, but you could look on the Roadmaster website for a PT Cruiser base plate to see what it looks like. I think I paid over $400 for it 10 years ago, but I would sell it to you for $150.
Looking at the photo of the 126, I can see it in my mind fabbing a bracket using the 3 bolts on each side, and a bracket bolted to the side of the frame horn with the tubes extending out about the level of the tow hook (through the fascia).
Pleas PM me if you are interested.....Rich

I am honestly swamped with other projects on my motorhome that I am thinking of scaling back and just renting a UHaul trailer for the short term until I have the time to deal with it all.... The tow bar cost me $75 and the rental trailer would only cost $140. To save $1500 I can live with leaving my car behind on long-distance trips. For now.

Also, Roadmaster does not seem to offer base plates for ANY sort of Mercedes Benz vehicle, regardless of year. Mercedes is simply not in their database at all. My guess is that it was either a hassle they didn't want to deal with or they didn't want to sell a product that damaged the transmission without yet another expensive product that disengaged the driveshaft.

It also seems that it's illegal in NJ to tow any weight car without supplemental brakes. Oh well. A tow bar is out of the question. Harbor Freight is honestly useless.

:rolleyes: uuuh--he didn't specify what type, size, etc. of "school bus." A, uh, school bus, isn't a #20K-#40K 'bus.'

When he goes to stop, w/o brakes on it, he may recall it's back there, when it breaks through the cheesy HF towbar.


OP:
The problems of trying to tow with a cheap $75 Harbor Freight tow bar are legion - best left to actual professionals in-the-field. Since Roadmaster has no Mercedes-Benz listing - I think the message is rather clear. Or at least it would seem to indicate that to me.