Why may I not tow my manual Suzuki Jimny on an A-frame behind my motorhome? The handbook says I will destroy the transmission, but I towed my old SJ 410 for thousands of kilometres without a problem. Suzuki SA was commendably swift in answering my query by e-mailing me the relevant pages in the handbook. That wasn’t exactly helpful.
Someone suggested that the Jimny can be towed, but that the engine must be run for a few minutes every 100 or 200 km. I did tow it for about 2 500 km recently, but only after removing the rear propshaft, which, understandably, is a hassle.
PC BADENHORST – By e-mail
Since Suzuki is unable to help we’ll have to resort to a vibration theory. Any rotating element has more than one critical speed where the rotational velocity excites the natural vibrational frequency of the system. In a vehicle, the system consists of the engine/flywheel, clutch, gearbox, driveshafts, rear axle assembly and wheels. These elements have been designed to work together so that the first critical speed is higher than what the vehicle can achieve.
When towing in neutral, the engine/flywheel, clutch and part of the gearbox does not rotate, so the natural frequency of the reduced system is completely changed. This means there MA Y be towing speeds that will cause harmful vibration and this MA Y damage any of the drivetrain components.
This implies that the towing speed and distance is important and should in most cases be kept as low and short as possible. Obviously, there are bound to be vehicles like the SJ 410 where you can get away with it, either by luck or design.
