Introducing Polyurethane Suspension Bush Kits for Rolls-Royce & Bentley models from 1997 to 2002

There are a couple of common questions regarding Polyurethane bushes:

• Will it make my suspension firmer and cause noise?
No - the hardness of the Polyurethane bushing has been carefully matched to provide the same response to damping forces as the original rubber bush. The Polyurethane material exhibits closely similar properties of absorption to the rubber bushes.

• Will it creak?
Again – no. Creaking is caused by “stiction”, where there is friction between components moving in opposing directions. This is resolved using the lubricant included in the kit in the manner recommended and by the inclusion, in some cases, of a slipper washer.

• Will the bushes need re-lubricating?
No, the lubricant “cures” leaving a semi-solid layer of lubrication between the two surfaces.

• Can I fit just one bush, or must all bushes be replaced at once with the Polyurethane type?
We recommend that you replace both bushes in each arm at the minimum. However, if one bush is worn, it is likely that others are close to the end of their serviceable life and you should consider replacing all of them.

A bundle is available enabling you to purchase a full set at a significant discount.

• How do they work?
In the original bushes there are two tubes or sleeves, separated by a rubber compound that is bonded to both tubes. As the suspension operates, the inner tube and outer tube twist in opposing directions, and inner tube shifts laterally against the outer tube. Eventually repeated stress causes the molecules in the elastomers to break down, characteristically demonstrated by the rubber splitting away – usually from the inner tube, or occasionally in the rubber itself. This allows the suspension arm to move more freely, causing problems with handling, tyre wear, noise and – eventually – safety.

In the Polyurethane bush the bushing remains almost static within the arm, and the inner tube rotates freely within the bush via the lubricant. The bush absorbs radial and axial forces, but there is no bonding to break down or degrade.