The suspension and steering of the TD and TF was one of the most significant advances over the TC, independent front suspension with coil springs and unequal-length double wishbones, derived from the Y-type saloon, replacing the TC's beam axle. Contemporary testers recognised the new layout as a major advance in ride and roadholding. The basic design proved durable enough to be carried forward into the MGA and continued, with detail revisions, until the last MGB in 1980.
Front Suspension and Hubs
The IFS uses a coil spring and unequal-length double wishbone layout. Each front wheel is located by upper and lower wishbones pivoting on the chassis crossmember, with the stub axle providing the steering pivot through upper and lower trunnions. Trunnions require regular greasing, worn bushes are the commonest cause of front suspension looseness. The BSF-to-Unified change at chassis TD/12285 affects wishbone pivots, trunnion assemblies, and slotted nuts.
The front hub and drum exists in four steel-wheel specifications by chassis: to 4250 (two-piece, felt retainer), from 4251 (single casting, felt retainer), from 6035 (single casting, steel cap), and from 12285 (Unified studs, steel cap). All TF steel-wheeled cars use the post-12285 specification. Wire-wheeled cars use separate splined hubs with separate drums.
Shock Absorbers
Both Girling and Armstrong hydraulic lever-arm shock absorbers were used during production. Both are reconditioned on a customer's own unit basis, with bolt kits available for either, the two are not interchangeable, and the bolt kits differ. The front shock absorbers form part of the upper wishbone arrangement, with the damper arms acting as the upper suspension links. The TD Mark II additionally received Andrex adjustable friction dampers alongside the standard hydraulic units.
Rear Suspension
The rear suspension uses semi-elliptic leaf springs with rubber-bushed shackles, rebound straps, and bump rubbers. The rear springs differ between TD and TF, separate part numbers, each with Silentbloc bushes. Spring assembly fixings are available in BSF and Unified thread. Synthetic interleaf pads reduce friction between leaves and eliminate the squeak that develops as original interleaving deteriorates.
Rubber pads, U-bolts, spring plates, distance tubes, and clip hardware complete the installation. Shock absorber brackets are side-specific and bolt to the chassis.
Steering
Rack-and-pinion steering was carried over from the Y-type. The rack is reconditioned on a customer's own unit basis and is specific to LHD or RHD. Three documented production changes affect the steering: at chassis TD/11111 (October 1951) the inner tie rod ball housing was redesigned; at TD/25973 (March 1953) a new tie rod outer end with improved seals was introduced; and at TF/4760 (April 1954) the tie rod, ball stud, and greaser threads changed from BSF to Unified, confirming chassis number is essential when ordering steering parts on an early TF as well as a late TD. The column is telescopically adjustable with rake adjustment, secured by a chrome clamp.
Track rod ends, gaiters, clips, slotted nuts, and split pins are common across both models. A complete rack gaiter kit (gaiters and four clips) is available.
Steering Wheels
The original 17-inch Bluemels standard steering wheel had three equally spaced chrome spring spokes and a celluloid rim and boss in mottled brown, an original-style centrepiece is available for restoration. Aftermarket Moto-Lita wood- and leather-rim wheels are available in 13-, 14-, and 15-inch sizes, with flat or dished spokes on the 14- and 15-inch sizes, plus a walnut-rim option. A TD/TF-specific boss kit is required for any aftermarket wheel, Moto-Lita wheels include the screws, but the boss kit must be ordered separately. Wheel centres come in plain aluminium and classic MG style; on aftermarket wheels with horn-push centres, the horn-push is inoperative on the TD and TF because the horn circuit uses a different earth from the MGB/MGC for which these centres were produced.
Ordering Considerations
Chassis number determines BSF or Unified thread for trunnion pins, hub nuts, wheel studs, and tie rod components, and on the TF, the tie rod and ball stud threads (BSF to chassis 4759, Unified from 4760). Wheel type (steel disc or wire) determines front hub and drum. Shock absorber manufacturer (Girling or Armstrong) determines the mounting bolt kits and rear brackets. The steering rack is specific to LHD or RHD.
For aftermarket steering wheels, specify wheel diameter and spoke profile (flat or dished) alongside the boss kit.