The MG ZR, ZS and ZT cover four substantially different suspension setups. The ZR uses the Rover 25 platform with MacPherson struts at the front and a torsion-beam rear axle, calibrated to MG-specific spring and damper rates. The ZS inherits the Rover 45's Honda-derived double-wishbone front and multi-link rear, widely regarded as the best-handling FWD Z-car. The ZT uses the Rover 75's MacPherson-strut front with alloy lower L-arms on a perimeter subframe, paired with a BMW-derived Z-axle multi-link rear.
The ZT 260 V8 has its own bespoke rear-wheel-drive suspension with Bilstein monotube dampers, Eibach springs and AP Racing rear brake calipers. State the car, engine and (where relevant) the 2004 facelift point before ordering.
ZR Front Struts and Torsion-Beam Rear
The ZR runs MacPherson struts up front from the Rover 25, with MG-specific spring and damper rates and a thicker front anti-roll bar for sharper turn-in. The lower L-arm carries forward and rear bushes plus a lower ball joint that is a routine wear item, the giveaway is a knock from the front over speed bumps, and the joint is best replaced as a complete lower arm. The torsion-beam rear is a single welded U-section with longitudinal trailing arms and integrated anti-roll-bar effect; there are no separate rear dampers and springs beyond the strut and coil set, plus the rubber bushes locating the beam at its forward pivots. ZR front hub bearings are a ZR-specific kit and are not interchangeable with the ZS bearing. Steering is hydraulically assisted rack-and-pinion shared with the Rover 25, with track rod ends, gaiters and PAS hoses available as service items.
ZS Honda Double-Wishbone Front and Multi-Link Rear
The ZS inherits the most sophisticated FWD suspension in the range: the Rover 45's double-wishbone front and fully independent multi-link rear, traceable to the Honda Domani platform. The ZS sits 20mm lower than the Rover 45 on sports springs, with stiffer rates, Delphi dampers, and uprated bushes on the front upper arms and rear trailing arms of the ZS 180. Front-end service items include the upper and lower wishbones with their ball joints (the lower outer is the more common wear item, and bush wear at the rear of the lower arm is a recognised cause of clonks), drop links, the anti-roll bar and front strut and spring assemblies. The multi-link rear inventory includes trailing arms, lower and upper control links, hub carriers and uprated ZS 180 trailing-arm bushes.
ZS front hub bearings (RUD100070) are catalogued separately from the ZR bearing. ZS 180 cars carry larger 282mm front and 260mm rear discs and 17-inch alloys with 205/45 R17 tyres, confirm the ZS 180 specification before ordering brake hardware.
ZT Front MacPherson and the BMW Z-Axle Rear
The ZT carries forward the Rover 75's BMW-derived chassis architecture. The front uses MacPherson struts on alloy lower L-arms mounted on a perimeter subframe, with stiffer spring rates, revised damping and a thicker anti-roll bar than the Rover 75. The rear is the BMW Z-axle multi-link, originally developed for the BMW Z1 in 1988 and later adopted for the BMW E36 3-Series and the Rover 75 / MG ZT, a complex arrangement with a long trailing arm and lateral links fixing camber and toe independently. Z-axle geometry gives the ZT its composed change-of-direction behaviour, but it has a well-known weakness: the rear upper trailing arms (top links) corrode where small drainage holes allow water in, and on neglected cars the link can rust through and snap.
Quality OE-equivalent replacements are widely available. Front lower ball joints are a common knocking-noise culprit. The ZT 190 received a lowered final drive to sharpen response.
ZT 260 Bespoke Rear-Wheel-Drive Suspension
The ZT 260 saloon and ZT-T 260 estate run on a substantially re-engineered chassis. The front retains MacPherson architecture but uses new uprights, Eibach linear-rate springs, a thicker anti-roll bar and Bilstein monotube struts (the yellow Bilstein casing is an instant ZT 260 identifier). The steering rack is moved forward to clear the V8 and runs at 2.5 turns lock-to-lock. The rear is fundamentally new: a six-mount steel subframe houses the Dana Hydratrak limited-slip differential and carries a multi-link with three lateral links per wheel (two steel, one alloy), a light alloy trailing arm, Eibach springs and Bilstein dampers, six Bilsteins in total, including an anti-tramp damper supporting the diff against V8 launch forces.
AP Racing twin-pot alloy rear calipers act on 332mm vented rear discs, with 325mm vented fronts using ZT 190-derived calipers. Mk2 (post-VIN 216) cars received revised spring and damper specifications, with 18-inch alloys and 225/45 ZR18 tyres.