Towing with a 108/109 - Page 2 - PeachParts Mercedes-Benz Forum

Litton · #16 10-13-2003, 06:42 PM

Well, I'm making good progress. Found out some useful info....the 4.5 and 6.3 seem to have essentialy the same tow rating of ~2900 lbs. This equates to a 19 or 20 ft airstream depending on the year. A good frame mounted hitch is nesessary and sway control is recommended. A reese hitch is even better then all stays level. Trailer brakes are mandatory. The 108/109 chassis are excellant for towing because the long wheelbase = less sway.

Actaully, the 280 sel (or se) 4.5 seems to be the best choice because the more conventional suspension is easier to "tweak" if desired. (Jury is still out on this point) Do a good service on the transmission and if in doubt pull it and go through it carefully. Keep the rpm's up in the hills by selecting the right gear. Change the water pump pulley to a smaller diameter to overcome the 280 tendancy to run hot with the A/C engaged.

The expected weak point will be the transmission if it's allowed to overheat. Aside from that .......good tow platform.

Safety is not a consideration as long as the vehicle limits are not exceeded. Choosing the correct color is vital.

300SDog · #17 10-13-2003, 08:09 PM

Mr. Litton,

Generally when fans speak of vintage cars "aging gracefully" they are actually talking about not driving the cars at all.... Am I wrong in assuming that late in life, with nothing to lose, you might be thinkin of taking extended road trips that could rack up thousands of miles at one clip touring the North American Continent repeatedly, including Canada and Mexico as you bloody well see fit? This sounds like a great idea!

Dammit, I'm someone who hates the mentality that vintage cars should never be driven on the open road....... and one day, in my dreams I'd love to steal "Concourse d'Elegance" 1930's SSK model Supercharged Mercedes Benz competitor to the Duesenberg and drive the machine into the sunset until the wheels fall off. These cars have souls of their own that deserve to be tested - and "aging them gracefully" at car shows and picnics is like makin dead stuffed animal trophies out of them - thats my opinion.

From my OTR truck driving days its understood that GVWR is ratio of weight shared on all axles among semi-tractor trailer combos thus:

optimum: 12,000 lbs front steering axle
optimum: 20,000 lbs tractor drive axles
optimum: 32,000 lbs trailer tandem rear axles, air brake assisted

= 65,000 (+or-) lbs. total GVW that weigh stations allow for commercial freight destributed on roughly 1:2:3 axle to axle to axle weight ratio from front to rear. Naturally, the lower the final trailer axle weight - the better the ride and the least amount of stress on the towing vehicle. But you've gotta include proportionate length between axles to make the ratio work - that's why many semis have sliding 5th wheels and moveable trailer tandem axles.

Granted that commercial semi combos weigh up to 65,000 lbs fully loaded and are better than 65' long - its obvious that trailer brakes are important...... but maybe not for you in your dream combo 4,000 lb. Airstream safely towed behind 5,000 lb. vehicle where the axle/weight ratios agree with proportions of commercial semi trucks on much smaller scale.

Here's my recommendation: You gotta check out the 2 1/2 ton Adenauer MBs that were actually built when Airstreams were in their prime..... http://www.mbzponton.org/valueadded/other/adenauer.htm

These are the ultimate elephants of the MB line - and their exterior coachwork more closely matches Airstream design than does any other car. So forget about puny 108s and 109s.... get the Adenauer instead.

I've seen several 5,000 lb dinosaur Adenauer 300 series Mercedes, say from '59 - '62 vintage, that have traded for peanuts in mid 4 figures on ebay "other models MB category".... you can bookmark ebay and keep checking until one turns up - or contact the Adenauer club at the site mentioned above to help you locate what you want to restore...... just dont tell em you are planning to install non-standard Mercedes engine and transmission into the car instead of the slow 3.0 litre 6 cyl engine used by MB at that time. Classic car buffs can be snooty when it comes to building custom vehicles, even when you use Mercedes parts exclusively.

Add specially mounted MB V-8 and tranny or something from the MB/Freightliner diesel engine line with highly acclaimed commercial MB tranny http://www.freightlinertrucks.com/trucks/components/mercedes-benz-transmissions.asp Thus you can probably build the vehicle/tailer combo of your dreams for less than $20,000 including the cost of the trailer!!! This is bargain compared with cost of new class C motor homes.

Talk with Freightliner - http://www.freightlinertrucks.com/freightliner-truck-dealers/united-states/default.asp Freightliner has recently cut a deal with MB for industrial strength diesels going into their light trucks; they can also provide expert advice regarding feasability and are qualified to handle the conversion and might do it for decent price, even using their own financing network, if they are interested and you speak with someone in charge. At the same time, seek out solid Adenauer chassis that just needs fiddly bits like seat covers, paint, air conditioning etc. You know it will be better than an ordinary Dodge/Ram truck - so go for it!!

Bottom line, you gotta do it to prove it can be done..... but the Adenauer frame is probably your best bet. Good news is that adding whatever engine and tranny you decide upon, whether largest Mercedes V-8 and transmission you can find or some kinda commercial MB diesel - it will add weight to front axle of the behemoth 300 Adenauer sedan that will ballance weight of the trailer on its own axle, as well as additional load on drive axle, making the combo safe and fun to drive...... and you can always pack the trunk with ballast if drive axles end up being light with respect to GVWR - as measured at Cat Scales in truck stops that determine axle weights independently.

Meanwhile if you wanna know more about engineering the perfect axle/weight ratio, pick up the AZ Dept. of Motor Vehicles Commercial Drivers License Manual that includes all the specs and info you need, assuming you have not done so already.

Am willing to bet the 300 Adenauer sedan stock suspension is proportionally ballanced at 5,000 + lbs and can handle the 4,000+ lb. Airstream easily.

pj67coll · #18 10-13-2003, 09:53 PM

An Adenauer? What about the breaks? They were drums all round were they not? I dont think I'd be towing something with stock breaks on such a car.

Actually I'd have to second the opinion of most people on this thread. Mercedes Benz's are not not good towing cars. The trailers used in Europe were invariably smaller and lighter than those of the USA. I've only used a Mercedes once with a trailer. My 71 108 280S. I certainly would never do so again. The trailer was a fairly small light one but the car's rear bumper (which usually sat high) was almost scraping the ground. If you really want to tow a vintage trailer, use a vintage Yank Tank, or a truck. Mercedes are of a different pedigree.

- Peter.

300SDog · #19 10-14-2003, 02:14 AM

Buncha baloney about drums vs. discs..... drums are actually better than discs for runaway downhill runs with heavy equipment where you sure as hell dont want em to lock up or overheat - Thats why semi-tractor trailers use DRUMS exclusively, albeit air assisted with 110lbs optimum pressure instead of fully hydraulic.

Just my opinion, but 4 wheel disc brakes are as unnecessay as automatic transmissions - just another sucker gimick designed to accomodate bulk of the market who basically dont take driving seriously.

Knowing MB, if they design brakes for 5,000 lb. vehicle designed to carry an additional 1/2 ton of passengers and luggage it sure as hell outta handle the trailer...... assuming the vehicle is driven intelligently using all the gears - downshifting for radical downhills..... or using the same gear running downhill that was used in climbing up the other side, common practice taught to CDL's.

Here's a hot one for you..... my '73 Moto Guzzi Eldorado has dual drums on the front and single drum on the rear. Sucker market was wondering why the Italians didnt just use one disc instead - as was widely marketed on competing superbikes of the era including Nortons and BMWs.

The answer? Drums were proven by expert motorcyclists at Mountain terrain of Lake Cuomo Italy, where all Guzzis are made, to provide superior control and handling to disc brakes..... especially on serious downhill runs where you need em most.

Again just my opinion, but newer Chryzler MB's suck because they invoke the lowest common denominator market that neither wants to experience driving nor pays much attention to operating the vehicle.... Basically, anybody who never shifts gears and jumps all over ridiculous ABS braking systems cant be called much of a driver at all.

pj67coll · #20 10-14-2003, 02:25 AM

240DD...

So I assume from this that you are saying a car equipped with drums will break more efficiently than an identical vehicle equipped with discs?

- Peter.

300SDog · #21 10-15-2003, 05:09 PM

Nah, more like comparing apples with oranges..... discs will produce more heat and might not be suitable for heavy loads - constantly warping rotors, chattering etc. The Adenauer could have 13" drums that can stop freight train.

Am standing on my opinion that Adenauer would be ultimate tractor/trailer Mercedes Benz that will pull Airstream trailer until hell freezes over - ballancing weight ratios to perfection...... with massive upholstery and uncommon luxury appointments to boot.

Is ther anybody in this forum who cannot visualize hauling 4,000 lb. airstream trailer behind 5,000 lb. Adenauer Benz?? This is the kinda stuff that makes history. Every one of us would go nuts to even see such a rig on the highways.