GRAYSTON SPRING ASSISTERS are not a new product by any stretch of the imagination but they just about the simplest way to reinforce sagging suspension on your towcar.

They are thick rubber strips which fit between the coils of your car’s road spring. When the car is laden lightly, the spring assister doesn’t really do anything at all. When a heavy load, such as caravan is applied however, the assister stops the spring compressing fully. This stops the wheel dropping too far into the wheel arch and improves the attitude of the outfit. Being made of a firm rubber compound however, the assister still retains a pliant ride.

Installing spring assisters

Fitting the spring assisters was fairly straight forward on our 1996 Volvo 850 estate. We lifted the car on a jack which extended the spring and increased the gap between the coils sufficiently for us to thread the rubber between them. The top and bottom surfaces of the assister are concave so when the jack is removed and the spring compresses again, it is locked in place. It took us around an hour to fit both using a standard trolley jack and a pair of axle stands.

In practice, the spring assisters lifted the ride height of the car by around 2.5cm (one inch) when the caravan was on the back. That doesn’t sound a lot, but it made a big difference to the way the outfit looked. In terms of ride quality, it was difficult to notice any difference aside from the hitch gear bottomed out less when traversing speed bumps or uneven ground.

With accessory spring sets starting from around £120, £30 for two rubber coil assisters is a good value option, particularly given the ease of fitting. Don’t expect miracles, but they do raise the rear ride height. Bear in mind though that they are no substitute for replacing worn suspension components.

They are available in different sizes ad getting the right one is vital. Halfords is one of the main suppliers and it has an application list in store or alternatively, you can visit the Grayston website for a list of correct sizes for your towcar.