Spot the grot
MGC and V8 problem areas
Wire wheels were optional at launch.
windscreen surround must be removed first. So check for over-sills (including cosmetic stainless steel items) or correctly repaired outer sills masking rotten inners.
Be wary of plastic wheelarch liners as they may hide rot, but if the car looks cherished they’re probably there for the right reasons. The spring hangers rot and next to the offside hanger is the battery tray (chrome-bumper cars have one each side), which rots. Make sure the tray is intact by checking from underneath and also ensure the floorpans are in good order – the original underseal cracks then peels off, leading to rot.
Because the top of the fuel tank is corrugated to strengthen it, water collects between the top of the tank and the underside of the boot floor, where it’s attached. If you can smell fuel, assume the tank has perforated and needs replacing, at about £100 (pattern) or £200 (genuine) plus fitting. Roadster and GT fuel tanks are interchangeable.
The GT’S double-skinned tailgate rots and so does any B or C’s scuttle, where it meets the base of the windscreen. Fixing rust here entails removing a roadster’s windscreen surround. Finish by checking the bottom of each door. New skins are £85 but a whole new door can be more cost effective at £400, as getting the new skin to fit properly is so involved. MGC doors are the same as post-1968 MGB items.
Oily bits
The C’s six-pot engine is based on the Austin 3-Litre’s, but the valves, springs and sump are unique. However, the main structure is identical and generally long-lived. After 80,000 miles the valve stem oil seals harden, so look for blue exhaust smoke as you accelerate through the gears.
The rocker shafts also wear – there’ll be a clattery top end. Don’t assume it’s just a question of the valves needing adjustment. If a new rocker shaft is needed a replacement is just £28.50 and it’s relatively easy to fit. Because the V8 is unstressed it should keep going forever if the oil and coolant have been changed regularly. The former is essential if the camshaft isn’t to wear prematurely while the latter is needed to prevent the engine corroding internally, leading to blocked coolant passages.
The C’s gearbox is based on the B’s but the two aren’t interchangeable. The first thing to go is usually the lay-shaft bearings, resulting in obvious whining. You can get the box rebuilt or fit a five-speed conversion, offering lower transmission losses (so economy is improved), better ratios, quieter operation and the ability to perform a faster clutch change. Most owners prefer to keep things original though. The V8’s gearbox also has a tough time, with wear common on second and third.
Vibration from the driveline signifies one or both of the propshaft universal joints has worn; considerable gearstick movement suggests worn or broken gearbox and/or engine mountings. Replacing propshaft joints is easy, and you don’t need to pay more than £110 for a new one. Engine and gearbox mountings are also straightforward to replace, if weighty, so both of these jobs are very much Diy-friendly.
The simple suspension doesn’t generally give problems, except for the kingpins. Unless they’re greased every 3000 miles they will wear.
Jack up the front of the car and try rocking the wheel at the top and bottom as somebody applies the footbrake. Any detectable movement means the kingpins need replacing at £170 per pair plus fitting. Allow a couple of hours for each side.
Lever arm dampers were fitted front and rear, which leak. It’s possible to swap to telescopics, but the ride will be harder. To really sharpen up the handling it’s worth fitting uprated front and rear anti-roll bars, which will transform the car’s dynamics for just £100 or so. Make sure all the rear tyre is visible – if it disappears under the wheelarch the springs need replacing at £60 plus a couple of hours per side to fit them.
All MGCS and B V8s have a servo, two on some North American models with dual-circuit brakes. If it feels like there’s no brake assistance it’s because the seals have failed or there’s damage to the main diaphragm in the servo, not allowing the intended pressure variations that gives the assistance. This is often accompanied by an air leak ‘hiss’ and the engine will usually be less smooth. Bank on spending about £330 for a new unit.
Trim and electrics
All the trim is available. A new hood plus fitting will set you back from £290 depending on what material you want. A set of new seat covers costs £590 for leather or £340 for vinyl, and carpet sets cost anywhere between £180 and £280.
Exterior trim is all available new, too, or you can pick up most parts on a used basis. However, the V8’s unique Dunlop composite steel wheels are complex and tricky to refurbish which is why a decent set costs well over £1000.
Until 1974 a pair of six-volt batteries were fitted – after this date a 12-volt unit was installed. Although neither system generally gives problems, there can be earthing glitches because of poor connections between the earthing strap and the body. The battery tray is behind the front seats (one on either side on 6-volt cars) so you’ll have to take the cover(s) off to check. Six-volt cars suffer from duff batteries if the car isn’t used regularly, as they drain each other, but converting to a single 12-volt battery is easy and cheap at around £50.