Mercedes Automatics & towing

[Irishrebel]

Hi all, new here, and I've posted this on a few sites to maximise potential replies: For about two years now I've been towing a large caravan (99 Bailey Senator Camargue, 2-axle, miro: 1241 kg) with a 99 Audi A4 2.5TDi, with no real problems. Just bought a lovely 98 E-Class estate auto with a 3000TD engine, very well kept. While pricing towbars for this, I've been given some advice that Mercedes auto trans. cars need to have an oil cooler for the gearbox fitted and an upgraded fan, maybe even a new radiator, in order to tow large caravans. I really thought such a heavy and torque-enriched car would do OK. WhatTowCar.com matches my model (well, nearest model I could find with all the right specs. input) as 5 stars with my caravan, and lists no problems for me. Does anyone agree I need to do these expensive upgrades? Tim.

 

[vincenz]

I think it advice is balls.

Does the manual specify the max braked towing weight?

 

[Shude]

Welcome to the forum!

I just tried searching for "towing" and "cooler" which resulted in 16 threads about the subject.

I have no additional information for you but that is where I would start.

 

[BTB 500]

You shouldn't need to do anything IMO, what is the braked trailer towing limit in your handbook? You would generally base a match on MTPLM rather than MIRO, by the way. I'd have thought the Audi A4 was pretty borderline, weight-wise?

 

[Dieselman]

Early 300Td available in mainland Europe used the space in front of the radiator for a transmission oil cooler. This was deleted on fitment of air-con.

Later cars (including all supplied to the UK) use a twin radiator to provide an oil cooler to the geabox via the cooling system.

 

[grober]

NECESSARY- probably not. DESIRABLE- probably yes. Most autotrans Benz have a transmission cooling coil built in to the engine radiator to cool the autotrans fluid. In older cars this sometimes corrodes allowing transmission fluid and coolant to mix - NOT A GOOD THING Compare the price of a new transmission V the cost of installing a separate transmission fluid cooler and draw your own conclusions. If you are driving 50 miles to the coast for the weekend that's one scenario--if you are touring on the continent doing long motorway miles in higher ambient temperatures then that's entirely different.

 

[BTB 500]

In older cars this sometimes corrodes allowing transmission fluid and coolant to mix

But that's surely nothing to do with towing ... it's either corroded or it's not??

 

[Bazzle]

IF? the gearbox gets too hot and the cooler in Rad isnt able to cope (even when NOT towing) the gearbox will go into limp mode. If this has never happened I would say it is all within its capabilities.Now if you were doing this in outback Oz or Africa where temps can exceed 40 centigrade I would prob be the next step cautious.

Bazzle

Bazzle

 

[grober]

But that's surely nothing to do with towing ... it's either corroded or it's not??

Agreed, it just an additional bonus to possibly take into consideration if the poster was thinking of keeping the car in the longer term and balancing out pros and cons.

 

[Bri957]

My old man did a lot of towing (caravan) with a 97 300TD, suffered no problems at all iirc.

To be honest even the old W123 230te was quite a good tow car, especially once the bowden cables had been adjusted slightly.

Good luck.

 

[Bobby Dazzler]

If yours doesn't have an oil cooler, it might be worth a transmission oil change at least to give it a sporting chance.

 

[television]

What a difficult thread, so many firms selling oil coolers.

Heat is the killer on auto boxes, why not look on a caravan club site

 

[Dieselman]

See post #5.

It has a cooler in the rad.

 

[television]

See post #5.

It has a cooler in the rad.

OK, thank you, even some 124's had those

 

[Bobby Dazzler]

Ahhh, sorry DM, I read it the opposite way, and assumed that 1998 would be an early 300TD. Sounds like a non-issue if it's considered a later car.

If I remember right the Haynes Caravan manual (yes, I do have one!! and it's very good by the way) covers oil coolers for automatic tow cars, but I keep it in the caravan so can't check what it says!!

I would imagine a 300TD would make a fairly relaxing tow car - plenty of substance, automatic, and a heap of torque. Our ML is much the same. Enjoy.

 

[Dieselman]

Ahhh, sorry DM, I read it the opposite way, and assumed that 1998 would be an early 300TD. Sounds like a non-issue if it's considered a later car.

1995 is early but only available in LHD.

If I remember right the Haynes Caravan manual (yes I do have one)

That took guts....

I would imagine a 300TD would make a fairly relaxing tow car - plenty of substance, automatic, and a heap of torque. Our ML is much the same. Enjoy.

I've only towed a trailor and a transit van but it's absolutely effortless...and surprisingly quick off the line still....

 

[Bobby Dazzler]

That took guts....

I could claim it was an unwanted gift which I didn't want to return for fear of upsetting the person who gave it to me. That would be a fib though!!

I also have The Haynes manual for Babies. The wiring diagrams are fairly difficult to follow though!!

 

[grober]

There's this. Claims a dedicated oil cooler will reduce oil temperatures by 25-30% http://www.autoboxes.co.uk/services.html and this from the camping and caravaning club and no I don't have one. http://www.campingandcaravanningclub.co.uk/Documents/Manual versus Automatic which transmission.pdf

 

[Bazzle]

There's this. Claims a dedicated oil cooler will reduce oil temperatures by 25-30% http://www.autoboxes.co.uk/services.html and this from the camping and caravaning club and no I don't have one. http://www.campingandcaravanningclub.co.uk/Documents/Manual versus Automatic which transmission.pdf

But NOT if the gearbox is holding temp in range thru rad cooler.

Only if temps exceed range would you need one to keep in range.

Does not MB auto have a thermostat in auto?

Bazzle

 

[maddog]

I used my E320 cdi for towing and apart from the drop in economy there was no difference in the engine temp or the way the box shifted .

Might be an issue if you were traversing the alps in the height of summer but i wouldnt worry about it