Auto gearboxes and towing. - concrete

In the Telegraph on Saturday HJ wrote that towing with a vehicle with an automatic gearbox is not recommended. He cited gearbox overheating issues and wear on the torque converter. My new Volvo XC60 D4 has a torque converter autobox. I specified it from new with a towbar. Does this mean the factory will do what HJ suggests for extra cooling given the specification of the vehicle? My caravan is not particularly big and weighs in at about 1350kg laden. Given my driving style I am not anticipating putting too much strain on the vehicle but I am now concerned that I may be damaging the transmission by towing at all. If that is the case why do Volvo offer the towbar kit as an option. Now confused. Help. I know there are several engineers and also long term caravaners on the forum who can offer a decent opion on this subject. Please. Cheers Concrete

Auto gearboxes and towing. - RT

I now support the suggestion that the site has been hacked and HJ's profile taken over by malicious foreign powers.

A conventional automatic, with torque converter, is the BEST form of transmission - as long as the trailer weight is within the car maker's towing limit - some, but no means all, brands treat towing as "extreme conditions" and require a more frequent service schedule.

Trailer towing limits are set with regard to all the extra stresses involved - including long Alpine climbs in peak summer.

Auto gearboxes and towing. - jc2

Many T/C autos are fitted from new with a cooler-have a look.There'll be pipes from the transmissiom to the radiator or to a seperate cooler.

Auto gearboxes and towing. - concrete

Thanks chaps. You have put my mind at rest. I did think that offering a fully wired tow bar as an option did indicate the manufacturers are confident that the vehicle will tow safely within it's limits without undue stress. The towing weight of my caravan is at least 300/400kg less than the maximum allowed for my vehicle. I will have a look underneath too, just to see what is there. The caravan club are of the same opinion, that a TC autobox on a properly constructed vehicle fit for purpose is the best for towing. It apparently makes decisions about correcting towing stress with gear selection a lot faster than I could.

Cheers Concrete

Auto gearboxes and towing. - RT

Thanks chaps. You have put my mind at rest. I did think that offering a fully wired tow bar as an option did indicate the manufacturers are confident that the vehicle will tow safely within it's limits without undue stress. The towing weight of my caravan is at least 300/400kg less than the maximum allowed for my vehicle. I will have a look underneath too, just to see what is there. The caravan club are of the same opinion, that a TC autobox on a properly constructed vehicle fit for purpose is the best for towing. It apparently makes decisions about correcting towing stress with gear selection a lot faster than I could.

Cheers Concrete

Some years back I had a Subaru Outback automatic - on an Outback specialist forum one one the contributors worked under contract for Subaru on their automatic transmissions - his unequivocal recommendation was to leave the transmission in Drive rather than "tiptronic"/manual mode as the transmission ECU would protect both the transmission and engine better.

Auto gearboxes and towing. - Cyd

Some manufacturers, when building a car at the factory with an optional towbar, also fit extra gearbox oil cooling capacity - which is why some OE optioned towbars seem very expensive.

Some maufacturers also carry out engineering tests of vehicles out in Nevada and Death Valley with fully laden vehicles towing laden trailers. The vehicle has to cope with seering temperatures, often on inclines with aircon going full belt too.

Whether either is the case with the XC60 I do not know - try asking the dealer

Auto gearboxes and towing. - RT

Some manufacturers, when building a car at the factory with an optional towbar, also fit extra gearbox oil cooling capacity - which is why some OE optioned towbars seem very expensive.

Some maufacturers also carry out engineering tests of vehicles out in Nevada and Death Valley with fully laden vehicles towing laden trailers. The vehicle has to cope with seering temperatures, often on inclines with aircon going full belt too.

Whether either is the case with the XC60 I do not know - try asking the dealer

The Americans introduced the SAE J2807 towing test for pick-ups to normalise the extravagant claims being made by truck makers - it's known as the "Davis Dam Grade" test, 11.4 miles of 5% at temperatures OVER 100 F and includes multiple restarts both forwards and reversing.

 

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