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MG MGB (1962 - 1980)

Last updated 27 November 2018


Buying Guide


  • Sills are the MGB's Achilles’ heel – these are complicated multi-panel structures and repairs are often bodged so be wary of cover sills and stainless-steel over-sills that may be hiding poor repairs.
  • Remove the front wheels in order to check the back of the front inner wheelarches – the box section here collects mud and rots away.
  • Wheelarches can rot so make sure wheelarch liners are hiding anything nasty.
  • Rear spring hangers are also vulnerable to tinworm.
  • Battery trays can disintegrate – you’ll need to check its condition from underneath the car.
  • Make sure the floorpans are in good nick.
  • On GTs, the double-skinned tailgate can rot.
  • Always check the scuttle where it meets the base of the windscreen – a fix here will mean taking the windscreen surround off (expensive).
  • Door bottoms rot, although replacement door skins are avaialble but fitting them can be involved.

Engine & Gearbox

  • A well-maintained 1798cc B-series engine should cover more than 100,000 miles between rebuilds.
  • Expect some tappet noise at idle.
  • At tickover, oil pressure should be 15-25psi, rising to 50-65psi at 3000rpm.
  • Ask the seller if the car using a lot of oil? The crankcase breather pipes can become blocked.
  • Another reason for high oil consumption is worn valve guides and oil stem seals – check for a puff of smoke when you apply the throttle.
  • If oil isn’t being burnt, then check for leaks at the front and rear crankshaft seals.
  • Three different transmissions were fitted to the 1.8-litre B: three-speed auto,and manual three-synchro’ or four-synchro’ ’boxes.
  • Clutch problems are usually caused by the carbon fibre release bearing breaking up.
  • But a spongy pedal can be caused by worn master and slave cylinders.
  • If the overdrive has failed, it could be because the electrics are playing up or the oil filter inside the unit needs replacing.
  • Vibration from the driveline on the test drive suggested one or both of the propshaft’s universal joings has worn.

Suspension, steering and brakes

  • Kingpins need to be greased every 3000 miles. Jack up the car and rock the wheel (while a friend applies the footbrake) – if there’s movement, the kingpins will need replacing.
  • Also visually inspect the front wishbone bushes to see if they have perished.
  • You should be able to see all of the rear tyre – if not (and the car hasn’t been lowered on purpose), the spring will need replacing.

Electrics and trim

  • Up to 1974 a pair of six-volt batteries were fitted – after this date a 12-volt unit was installed.
  • Both systems are pretty reliable, but earthing problems can be caused by poor connectins.
  • If the interior is tired, don’t worry – all the trim is still available, but the cost of replacing it can soon add up.
  • Budget around £150 if you want a new hood fitted.

Can I run it on unleaded?

  • No. Hardened valve seats have to be fitted to the B-series before it'll run on unleaded, and the ignition needs to be retarded a couple of degrees as well.
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