The K-series engine and PG1 five-speed gearbox are mounted transversely in the rear subframe as a single combined powertrain assembly. The mid-engine layout means the entire drivetrain is carried by the rear subframe rather than being supported at the front of the car, which places considerable demands on the mounting system, it has to isolate vibration, control torque reaction, and maintain the precise drivetrain position required for the driveshaft and exhaust alignment. The MGF and TF use a four-point mounting arrangement: a right-hand engine mounting and a left-hand engine mounting carry the weight, while two horizontal tie rods (one at the engine's front and one at the rear) control fore-and-aft movement and the torque reaction from the transverse drivetrain under acceleration and braking.
Right-Hand and Left-Hand Engine Mountings
The right-hand engine mounting sits between the engine and the subframe on the flywheel side of the engine, and is where the manual and automatic variants diverge. The manual-transmission mounting has its own part number; the Stepspeed CVT automatic uses a different mounting to account for the differing torque characteristics and drivetrain weight distribution of the automatic transmission. The right-hand mounting is carried by a bearer bracket bolted to the engine itself, with the mounting arm assembly connecting the bearer bracket to the rubber mounting. The complete right-hand assembly is therefore: engine bearer bracket, mounting arm, rubber mounting, and the associated bolts (two long and one short bolt securing the bearer bracket to the engine, plus the mounting arm-to-bearer bracket bolts).
The left-hand engine mounting sits on the gearbox side of the assembly and is where the gearbox carries a share of the powertrain weight. It comprises a rubber mounting, a distance tube, a through-bolt, and the left-hand engine bearer bracket that bolts to the gearbox casing. As with the right-hand arrangement, the left-hand bearer bracket differs between manual and automatic specification, the automatic bracket uses three bolts to the gearbox while the manual bracket uses two, reflecting the different gearbox housings.
Front and Rear Engine Tie Rods
The two tie rods are the MGF/TF's equivalent of a conventional gearbox or torque mount. The right-hand engine tie rod connects the right-hand mounting arm to the subframe and resists the engine's tendency to rock fore-and-aft under load. The rear engine tie rod, a substantial casting with an integral housing and bush, connects the rear of the engine to the subframe and carries the primary torque reaction. The rear tie rod is the single most heavily loaded mounting component on the car, and it is another manual/automatic differential: manual cars use one specification of rear tie rod, automatic cars use a different, heavier-duty variant to suit the CVT's torque characteristics.
A worn or detached rear tie rod allows the engine to shift rearwards under acceleration and forwards under braking, producing a noticeable clunk and affecting driveshaft alignment. Replacement of the rear tie rod's housing-and-bush assembly is a known service item, and the housing is secured by four screws to the subframe for replacement without complete subframe removal.
Engine Bay Bracing Strut
Both manual and automatic cars have a bracing strut assembly in the engine bay, a structural tie running between the body and the engine/subframe area that contributes to the stiffness of the rear structure. The manual and automatic variants use different part numbers for the bracing strut, reflecting the slight differences in engine bay layout between the two transmission types. The strut should be checked for straightness and corrosion, particularly at its mounting points, as a distorted or corroded strut affects rear-end rigidity and load paths through the body.
Ordering Considerations
The single most important identifier for Engine & Gearbox Mountings parts is manual versus Stepspeed CVT automatic. The right-hand engine mounting, the right-hand mounting arm, the rear engine tie rod, the left-hand engine bearer bracket, and the engine bay bracing strut all differ between manual and automatic specification. The left-hand rubber mounting itself, the front right-hand tie rod, most fixings, and the tie rod housing-and-bush assembly are common across both transmission types.
When ordering, confirm the gearbox specification, PG1 manual (fitted to the vast majority of MGF and TF cars) or Stepspeed CVT (fitted to a small minority, primarily MY2000 MGF and TF 120). Worn mountings typically present as a rough idle feel, vibration through the floor and seats, or a distinct clunk on power application or overrun, particularly from the rear tie rod, which takes the greatest share of the powertrain's torque loading.