The engine and gearbox in the TD and TF are mounted to the separate boxed chassis through a combination of rubber-bushed mountings that isolate drivetrain vibrations from the body structure. The mounting arrangement is shared between the TD and TF, one of many chassis and mechanical components that remained unchanged at the model transition in late 1953. On the TD and TF's separate chassis, worn mountings have wider consequences than on a monocoque car, because the engine's position relative to the body, propshaft, and exhaust system is determined entirely by the mountings rather than by the structural rigidity of a unitary body.
Front Engine Mounting
The front engine mounting comprises a single rubber block carried on a bracket that bolts to the front of the chassis. The engine mounting rubber, its two through-bolts, four nuts, and the mounting bracket are universal across all TD and TF cars.
The rubber will harden and crack with age, particularly on cars stored for extended periods, and a deteriorated front mounting allows excessive engine movement that can strain the exhaust manifold connection, accelerate wear in the engine control linkage, and cause the fan to run too close to the radiator. A failed front mounting will be visible as excessive engine rock under load and on deceleration.
Rear Engine Mounting
The rear mounting is a more complex arrangement carried at the back of the gearbox. It comprises a bracket, a rubber kit containing two mounting rubbers and a rebound rubber, a fork assembly, a clevis pin with split pin, a cup washer, a main nut, and a securing split pin. The rebound rubber limits upward engine movement, the two main rubbers cushion downward load, and the fork locates the gearbox to the chassis cross-member. The complete rear mounting rubber kit is the recommended way to renew the rubbers, as all three components age together. The rebound rubber is sometimes missing on cars that have been dismantled and reassembled without reference to a parts catalogue, its absence allows the engine to lift excessively under load, placing stress on the gearbox mounting and altering the propshaft angle.
The clevis pin and split pin securing the fork should be inspected at every service, as a failed clevis pin will allow the rear of the drivetrain to drop, potentially damaging the propshaft and rear mounting bracket.
Engine Control Link
The engine control link assembly provides a steady bearing between the engine and the chassis, controlling lateral engine movement about its mounting points. The link uses rubber bushes and cup washers that deteriorate over time, and a worn engine control link allows the engine to rock laterally, which manifests as a clunking noise under acceleration and overrun. The four-bush set and the four-cup-washer set are available separately for overhaul, or the complete link assembly can be renewed. The engine-side bracket and the chassis-side bracket are available as individual items.
Related Production Change
An additional body mounting point was introduced on each side of the chassis from chassis number TD/20749 in October 1952. This change relates to body-to-chassis fixing rather than engine mountings, but it is a recognised production split that owners of later TDs and all TFs will encounter when working around the engine bay.
Signs of Worn Mountings
Worn engine or gearbox mountings manifest as excessive engine movement visible under the bonnet, clunking on clutch engagement or throttle application, poor gear selection caused by misalignment, and vibration transmitted to the body. On the TD and TF, where engine position determines the alignment of the entire drivetrain from clutch through propshaft to rear axle, worn mountings can also cause clutch drag and propshaft vibration that might initially be diagnosed as faults in those components rather than in the mountings themselves.