Is my Volvo V70 suitable for towing? My 2007 Volvo V70 diesel automatic has done 54,000 miles. When towing a caravan, I get a warning saying "transmission service required" after 30-40 miles. The dealer recommended that the transmission oil should be changed (for £250), although he cannot guarantee that this will solve the problem. There is also a solenoid, which might be sticking. Is an oil change likely to clear the problem? When you tow with an automatic that does not have additional transmission cooling, the oil is prone to overheat. I suspect that is what has happened to yours. The solenoid will be in the servo valve box that controls the gearchanges. A specialist can recondition these, but a dealer will usually prescribe a new valve box for about £2,500.