towing w/ a 87 300sdl
 

i'd like to tow a #2000 utility trailer on what i hope to be a relatively uneventful cross country trip. i've heard the term "engine encapsulation" bandied about, but i'm not sure quite what the issue is. i see mostly references to overheating? the car should be getting good airflow the whole trip, and there's a new radiator in the car, is overheating going to be a terminal issue or should taking it slow suffice?

the car lacks a tow hitch and presumably wiring for trailer lights. i assume my local mercedes specialist will be able to help me here.

comments? what else do i need to consider?

There is a factory tow hitch for the W126 (class 1) that's pretty much plug and play. I took one off my 500SE - odd looking creature sort of fish hook shaped. EBay might be a good source to find one.

In regards to the trip. That's pretty much going to depend on the overall mechanical shape of the SDL. Obviously pulling a trailer is going to put some stress on a 23 year old car. Your SDL does have engine encapsulation, or sound proofing just forward of the firewall -not sure if that has any significance in towing.

As I recall forum member pawoSD has towed quite a bit with his W126. He might have some good technical input he could share with you.

any idea if the tow hitch includes the wiring kit for brakes / turn signals / running lights on the trailer?

Indeed I have. :D

I have towed probably about #1300lbs at the most so far, though I have pulled another car 15 miles with a tow strap before....it did that pretty easily too going 30mph.

You will need the proper hitch, and the hitch can only take about 200-300lbs of weight on the hitch itself, so the trailer needs to be very balanced. Go 55-60mph and you should be fine, just don't stress it or go real fast, it has the power to do so, but it will put a lot of excess heat and strain on the transmission, the engine will handle such a task with 0 issues if everything is in decent shape (cooling system especially). For the trailer wiring you need to splice into the existing wires at the rear lamps and use a converter that pairs the single lights on the trailer to the separated blink/brake on the SDL. All available at local stores. I use LED lights on my trailer to reduce load on the electrical system of the car.

before attempting this, verify your fan clutch works, and your aux fan as well.
if pulling hills, it's a good idea to run the heat in the car.
if temp climbs anywhere near 120, slow down!

2000lbs is a good idea to have electric assist braking...

First off, if just using a truck is out of the question, then consider adding a Pyrometer and oil temp gauge. Next I would consider water injection in order to cool the intake air charge, thus removing heat from the cooling system. Turbo life will be extended, evaporated water will aid in combustion with the introduction of additional O2.

Since you are hauling a trailer anyway, the trailer could carry the water with the pump assembly under the hood. Very simple system.

you might consider fluid changes to ensure all is well.

Best of luck, it sounds like an adventure.