Polyurethane replaces the standard rubber suspension bushes with a harder, more durable material that resists the compression set and gradual deterioration that affects rubber over time. Rubber bushes provide good vibration isolation when new but degrade progressively, by the time an MGF or MG TF reaches 15 to 25 years old (which covers the entire production range), the original rubber bushes are typically well past their intended service life and often exhibit visible cracking, voids, or complete collapse. Polyurethane maintains its properties for significantly longer, delivering consistent suspension geometry control and a more precise feel through the car's remaining ownership life. The trade-off is that polyurethane transmits slightly more road noise and vibration to the cabin than fresh rubber, though on a car whose rubber bushes have been in service for two decades, polyurethane typically feels both sharper and quieter than the worn originals because the old rubber had stopped damping properly.
Front Bush Kit, Common MGF and MG TF
The front polyurethane bush kit is a single specification that fits both MGF and MG TF, a useful simplification reflecting the common front suspension geometry between the two models. The kit covers the front wishbone bushes at their various mounting positions. This is usually the first polyurethane upgrade owners fit, the front suspension does most of the steering work, and worn front bushes produce the most immediately noticeable symptoms (vague steering feel, clunking over bumps, accelerated inner-edge tyre wear).
Rear Bush Kits, Model-Specific
The rear polyurethane bush kits are split into two model-specific kits reflecting the fundamentally different rear suspension architecture between MGF and MG TF. The MGF rear bush kit covers the Hydragas-era rear suspension: the rear lower arm bushes (inner and outer), tie bar bushes, track control rod bushes, and anti-roll bar mounting bushes appropriate to the MGF rear geometry. The MG TF rear bush kit covers the coil-spring multi-link rear suspension: the rear lower arm bushes, compliance bush, trailing link bushes, and rear anti-roll bar mounting bushes appropriate to the MG TF rear geometry. The two kits are not interchangeable, ordering the wrong kit produces parts that will not fit.
Engine Steady Bush Kit
The engine steady bush kit covers the bushes in the engine steady bar (torque reaction rod) that links the engine/gearbox assembly to the bodyshell to control powertrain rock under load. Worn engine steady bushes produce a clunk on the overrun (throttle release) and on throttle take-up, most noticeable in first and second gear at low speeds. The polyurethane replacement eliminates this compliance and is a cost-effective improvement at modest outlay, a common "while I'm fitting the rest of the bushes" addition.
MG TF Shock Bottom Bush and Bolt Kit
The MG TF shock bottom bush and bolt kit addresses a known weakness in the original MG TF lower damper mounting, the original bolt specification had over-generous tolerance between the bolt shank and the inner bush diameter, producing play that caused the lower mounting to squeak and knock over time. The kit provides a precision-ground-shank bolt with the last threads deliberately deformed for self-locking, combined with a polyurethane lower shock bush that eliminates the compliance. This is the definitive fix for the MG TF lower damper mounting rattle that many higher-mileage cars develop. Suitable for all MG Rover-era MG TFs up to and including 2005 MY, not for Spax installations or MG Motor (NAC/SAIC-era) MG TFs, which have different mounting arrangements.
MGF Lower Shock Bush, Set of Four
A dedicated MGF lower shock bush polyurethane set of four is catalogued for owners replacing just the lower damper bushes without the complete front or rear bush kit. Four bushes cover all four corners of the car. This is the minimum-intervention option for anyone noticing play or squeak at the lower shock mounting points but not wanting to commit to a complete suspension bush refresh.
Fitting Guidance
Polyurethane bushes should always be fitted with the grease supplied in the kit, this allows the bush to rotate within its housing under suspension movement rather than relying on rubber deformation. Fitting polyurethane bushes dry causes squeaking over time as the bush surface and the mounting housing work against each other without lubrication. A light reapplication of the supplied grease every few years, typically at the same time as brake service, keeps the bushes quiet indefinitely.
Replacement of polyurethane bushes, when eventually needed, is a cleaner operation than rubber-bush replacement because polyurethane does not bond permanently to the metal surfaces it contacts.