How To Overhaul Your MGB Suspension: What To Check And When To Replace

The MGB ran from 1962 to 1980. Many cars still on the road today are using the original, and often tired, suspension components, and most of them haven't seen a proper overhaul in decades. Bushes crack. Leaf springs sag. Armstrong dampers slowly weep fluid. Coil springs settle. A B that once felt crisp and connected gradually becomes vague, floaty, unsettled at speed and less satisfying to drive than it should be.

If you're planning a full MGB suspension rebuild, or simply tracking down a knock that's been nagging at you for months, our MGB suspension parts page covers everything from a single bush to a complete conversion kit. This guide takes you through the whole system: what the B's suspension actually is, what to look and listen for, and which parts will give you the most return for your effort and budget.

What type of suspension does the MGB have?

Understanding the original design is the best starting point for any MGB suspension work. It helps you diagnose problems accurately, makes sense of why certain upgrade kits are packaged the way they are, and means you're far less likely to order the wrong thing.

MGB suspension: what your car is telling you

Most suspension wear announces itself before it becomes a safety issue, but you need to know what you're listening for. The symptoms below point directly to specific components, which saves you guessing and revisiting the same job twice.

Reading front suspension wear on your MGB

These are the signals worth acting on:

• Clonking or banging over rough surfaces, especially at low speed. This almost always points to worn wishbone pivot bushes or play in the trunnion at the base of the swivel pin. After decades of use, the original rubber hardens, cracks and stops properly locating the wishbone. You'll often feel a kickback through the steering wheel at the same time, particularly over sharp-edged potholes.
• Vague or wandering steering on a car that was once precise. Before looking at the steering rack or column, check the king pins and trunnions. When those joints wear, camber and castor drift from the factory settings, and no steering adjustment compensates for that kind of play.
• Uneven or rapid tyre wear across the front axle. This points to geometry errors caused by worn MGB suspension bushes, not a fundamental geometry problem. The correct order is: new bushes first, geometry check second. Doing it the other way round is a waste of time and money, because worn bushes let the geometry drift again almost immediately.
• Excessive body roll, or a floating sensation at speed. This points to tired or failed dampers. On a car still running original Armstrong units, the fluid seals deteriorate over time and damper oil escapes. A unit that's lost its fluid provides almost no resistance to suspension movement. Improving MGB handling and brakes both start here, before anything else.

A good reference before ordering anything is the MGB suspension diagram in our printed Moss Rimmer catalogue. It shows the full front assembly clearly and is a practical companion when you're working out what's actually needed.

Rear suspension wear: what sags, leaks and eventually gives out

The rear end tends to deteriorate less dramatically than the front, but it does deteriorate. Rear Armstrong lever arm dampers suffer the same seal failure as the fronts, just with less obvious symptoms in the steering. The leaf springs sag progressively, which lowers the rear ride height and shifts the geometry; a car sitting noticeably low at the back, or one that feels wallowy on undulating roads, has usually got tired springs and dampers working together to make things worse.

Before ordering any MGB suspension parts for the rear, check the spring U-bolts, front eye mountings and shackle plates for corrosion. These are structural components, and on a car with a wet or salty history they can be in poor condition well outside your planned rebuild scope. An MGB rear suspension diagram covering the full axle assembly, U-bolts, rebound straps and spring mounts is included in our catalogue, and it's a valuable companion for any rear suspension work.

From here, the repair options split into two broad categories: restoring to standard, and going further.

MGB suspension parts and the rebuild baseline

Whether you're working on a barn find or refreshing a car that's been sitting for a few years, the rebuild baseline is the same. Start with what wears: bushes, springs, dampers. Get those right and the car will feel noticeably different almost immediately.

SuperPro polyurethane MGB suspension bush kit: why rubber replacements rarely make sense

Replacement rubber bushes are available for a like-for-like swap, and they're the right choice if originality is paramount. For most owners doing an MGB suspension rebuild, though, polyurethane is the more practical option. SuperPro's MGB suspension bush kit uses a material 25 to 30% stiffer than factory rubber, and it doesn't degrade in the same way. It's unaffected by UV light, water, salt, oil or petrol, and it won't soften with age the way original rubber does. Front and rear MGB suspension bush kits are available separately, or as a full car set that covers both axles in one order.

The improvement when you swap cracked original MGB suspension bushes for SuperPro units is immediately apparent. Steering response sharpens, the car feels more connected, and any remaining clonks either disappear or point you directly to wherever further work is needed.

MGB front suspension parts: what a complete rebuild covers

If you want to rebuild your front suspension to spec and leave nothing to chance, a full strip takes in:

• Wishbone pivot bushes, lower ball joints and trunnion seals
• King pins with associated circlips and taper pins
• Front coil springs (checking ride height against the correct spec for your model year)
• Dampers, whether you're refreshing the Armstrong units or converting to telescopic

Individual MGB front suspension parts are all listed on our site, but an MGB suspension kit that bundles the key wear items together is usually the most practical approach for a full job. If the car's history includes a wet climate or years of outdoor storage, check the lower wishbone arms and spring pan for corrosion before ordering: replacement arms are available, and it's much better to know upfront.

The rebuild baseline is a solid foundation, but it still leaves the Armstrong dampers in place. If those are past recovery, the next decision is which route to take.

MGB front suspension upgrades: going telescopic

Replacement Armstrong lever arm dampers are increasingly scarce, and units in reliably good condition are harder to find than they were. For most owners, the most rewarding MGB front suspension upgrades involve swapping to a telescopic arrangement. The question is how far you want to go.

Choosing replacement front dampers for MGB

The accessible route uses a bracket conversion kit that allows replacement front dampers for MGB to be fitted alongside the existing coil spring and wishbone. The lever arm body stays in place, with valves removed and the unit drained, serving as a structural link. It's a relatively contained job, and the range of dampers available gives you real choice over the final character of the car.

Koni telescopic shock absorbers are one of the most popular choices for the bracket conversion route: adjustable, respected across the classic car world and well suited to the spring rates on a standard MGB. GAZ front shock absorbers offer a similar adjustable setup and are available in standard or lowered specifications to match your intended ride height. Whatever you fit, always work in pairs; a single new damper alongside a tired one creates an imbalance that's worse than running two worn units together.

Bilstein shock absorber conversion kit: the committed front end upgrade

The Bilstein shock absorber conversion kit takes a different approach entirely. Rather than working alongside the existing lever arm body, it removes the assembly and positions the Bilstein unit between the steering knuckle and coil spring, supported by a new upper control arm and tube shock mount. This requires permanent modification to the front crossmember bump stop brackets, so it's a one-way commitment. Worth knowing before you pick up the angle grinder. Bilstein shock absorbers use a gas pressure monotube construction, which delivers consistent damping force across a wide range of suspension movement and road conditions. Fitting the front Bilstein shock absorber conversion kit together with the matching rear kit gives you the most coherent result across both axles.

MGB rear suspension upgrade: springs, dampers and beyond

It's tempting to focus all the attention on the front end, but the rear is where much of the MGB's handling character lives, and much of its handling compromise. A good MGB rear suspension upgrade changes the feel of the whole car.

Replacing leaf springs and rear telescopic dampers

Parabolic leaf springs are the popular choice for a road car used regularly. A single leaf design, they're lighter than the original multi leaf pack, give a smoother ride without the friction between the leaves, and they don't suffer from the inter-leaf wear that eventually affects the original springs. GAZ, Koni, Spax and Bilstein all offer rear conversion kits or damper options compatible with the existing axle and spring mounts. The GAZ and Koni units are adjustable, which makes it easy to balance the rear damping against whatever you've fitted at the front.

For cars where ride height is the primary concern, a matched MGB suspension lowering kit addresses both axles with components designed to work together rather than in isolation.

MGB 4 link rear suspension: the complete transformation

For a more fundamental change, Frontline Developments' multilink rear suspension system (available through Moss Rimmer) replaces the entire leaf spring and lever arm arrangement with coilover dampers and trailing arms. This type of design is often referred to in the MGB community as an MGB 4 link rear suspension conversion. The leaf spring's inherent limitation is that it tries to do two jobs at once: locate the axle and absorb road shock. A multilink design separates those functions. The car benefits from both improvements at the same time. It's a significant undertaking, both in terms of the work involved and the investment, but on a car built for regular fast road use the results are substantial. Frontline Developments kits are available through Moss Rimmer.

Do you have the parts for an MGB front suspension coil over conversion?

The coil over conversion sits at the top of the MGB front suspension upgrade ladder. Is it the right choice for your car? That depends almost entirely on what you're using it for.

What the MGB front suspension coil over conversion involves

Rather than working within the constraints of the original crossmember and lever arm layout, a coil over conversion replaces the separate spring and damper with a combined coilover unit, mounted via a new upper wishbone assembly. The spring platform on the damper body is threaded, so ride height can be adjusted precisely without changing springs. Moss Rimmer's front suspension coil over conversion doesn't require extensive modification to the front crossmember, which means the job can be reversed if the car ever needs to return to standard: a meaningful consideration for a concours build or a particularly original car. The coilover unit is designed to accept different spring rates, so the front end can be set up to match your intended use.

Coil over or telescopic: choosing the right approach for your build

Think about this one honestly before committing. Is your car a weekend driver, used for club runs and long tours? A telescopic damper conversion with fresh SuperPro MGB suspension bushes will transform it for considerably less outlay. Is it a car you're building specifically for fast road or regular track use? The coil over conversion gives you a level of height adjustability and geometry consistency that a bracket-based telescopic setup can't match.

This is the territory of specialist upgrades for MGB. A higher-investment job that transforms the front suspension rather than restoring it. The MGB suspension upgrade kit route remains the more accessible starting point for most builds, and it's where we'd suggest beginning if you're not sure yet what the car is going to become.

The full range of MGB suspension upgrades is on our MGB suspension parts page. Whether you're working through a full MGB suspension rebuild or hunting down a single part, we've been dealing with B-series suspension long enough to help you get it right.

Disclaimer

This guide is intended for general information purposes only. While we've taken care to ensure accuracy, vehicle specifications, parts compatibility and product availability may vary depending on your MGB's model year, chassis number and specification. Always cross-reference with your vehicle's documentation and consult a qualified mechanic before carrying out suspension work. Moss Rimmer accepts no liability for any loss, damage or injury arising from reliance on this content.