Towing cooling upgrades for manual C220?

[GaryBarnett]

Hello folks, first post here which I hope someone can advise on.

I soon take delivery of a 2010 C220 diesel estate (blue efficiency). I didn't go for a factory fit towbar due to the price. I fear this may have been an error because although a retro-fit towbar is cheaper (£350 compared to £660 from MBZ) Mercedes specify that the car needs to have:

Radiator fan upgrade.
Gearbox oil cooler (for a MANUAL gearbox!!!!).

Total cost for this is around £1200 (not including the towbar!).

Anyone know why a manual gearbox needs extra cooling? I understand that autoboxes need plenty of cooling but its the first I've heard for a manual.

Thanks

 

[jefrs]

Depends what you are towing. Engine and gearbox have to work hard towing a caravan. A 220 is going to work very hard and need extra cooling. A bigger engine has more muscle but will still get warmer than normal. Gearbox cooling is normal for hard-working engines. A short occasional run to the tip with a light trailer is another matter.

 

[GaryBarnett]

Thanks, I'll be towing a caravan with a maximum gross weight of 1490kgs. The C220 diesel has a maximum towing weight of 1800kgs. Its the first time I've heard of cars needing such extensive mods to be used for towing, its just a bit annoying that it doesn't state this anywhere in the literature.

I've spoken to one MBZ service department and was told that although the "official" line is that these mods have to be done, in the real world they're only really necessary if towing under severe conditions (ie. maximum towing weight, hot climate, steep hills etc).

Looks like we'll have to start going on holiday in November!!!

 

[killwilly]

Thanks, I'll be towing a caravan with a maximum gross weight of 1490kgs. The C220 diesel has a maximum towing weight of 1800kgs. Its the first time I've heard of cars needing such extensive mods to be used for towing, its just a bit annoying that it doesn't state this anywhere in the literature.

I've spoken to one MBZ service department and was told that although the "official" line is that these mods have to be done, in the real world they're only really necessary if towing under severe conditions (ie. maximum towing weight, hot climate, steep hills etc).

Looks like we'll have to start going on holiday in November!!!

When towing a caravan it's best to ignore the specified maximum towing weight. Never exceed 85% of the vehicles kerb weight if you are new to towing, that will prevent the tail wagging the dog.

 

[GaryBarnett]

The C220 estate has a kerbweight of around 1670kgs so I'm towing at around 89%, as I've been towing for 23 years I'm not overly concerned. I'm just more intregued as to what sort of cooling is necessary to a manual gearbox & how it works. The manual gearboxes I've been used to in the past have had a form of "splash" lubrication, rather than the pressurised/pumped type of an auto. Obviously in an auto the torque convertor generates a lot of heat which needs to be dissapated, but in a manual the job of the T/C is effectively the clutch.

 

[Mad4Coupes]

IIRC if the engine was going to be under any constant strain MB recommended a 700w fan as the upgrade. I believe it was also on the EPC but its been so long the memory could be sketchy...

 

[GaryBarnett]

I think I'll get a price from an independant specialist and see what they say and compare it to the MBZ main dealer. If it is definitely, 100% required & it has to be from a MBZ main dealer, anyone want to buy a wife or child (prefereably both!!!)?

 

[jefrs]

On a manual the clutch does not slip, but a torque converter does, then the autobox uses a series of wet-plate clutches to change gear. On e.g. a rally car, even a manual box would be given an oil cooler, because it is going to get thrashed, maybe one for the engine too. A fan can assist cooling but a bigger radiator is even better.

If you effectively double the weight of the vehicle by hauling a caravan, plus passengers and luggage, the the engine/gearbox has to work twice as hard, probably over twice as much heat produced to be got rid of.

Automatic is perhaps not the best transmission for towing: if one of those clutch plates start slipping (they are stuck on with water-soluble glue, 'cos they run in ATF) then it is transmission re-build time.

I know of one case where a 2.3L Volvo would not tow its caravan unless the aircon was turned off. And the local donkey wallopers try to move horse boxes behind 2L Subarus, doh!

 

[easyonthegas]

towing upgrade

Have W204 C250 CDI with autobox

I have also been told that the cooling fan needs to be changed from original 400W to 600W motor. As need to maintain warranty, not much choice but to agree.

 

[timskemp]

I think I'll get a price from an independant specialist and see what they say and compare it to the MBZ main dealer. If it is definitely, 100% required & it has to be from a MBZ main dealer, anyone want to buy a wife or child (prefereably both!!!)?

If you sell the wife and child maybe you won't need such a big caravan??

 

[easyonthegas]

Have now collected car and whole fan assembly was changed for the larger 600W unit.
Hidden away on p305 on the owner manual it states "If you have trailer tow hitch retrofitted, changes to the cooling system may be necessary, depending on the vehicle type"

Also note that the service B schedule changes once you have a tow bar fitted, see Mercedes-Benz ESS