This guide provides a background to the MGB and covers the key areas you should look for when buying an MGB.  The matters covered in this guide are not intended as an overall vehicle buying guide; instead they cover some of the issues specific to MGB’s that you should check when considering a purchase. 

The youngest MGB’s are now over 25 years old and accordingly every car has a different history, with differing levels of maintenance, quality of repairs, and usage.  We strongly recommend that if you are unfamiliar with these cars that you take an expert along or at the least ensure the car is professionally inspected. 

This guide must not be relied upon exclusively. 

The MGB Roadster was released in 1962 as a replacement for the MGA.  In 1965, the coupe MGB GT was released.  A six cylinder version known as the MGC (& MGC GT) was launched in 1967, but ceased production after only two years.  A V8 engined version, available in GT coupe form only, was produced from 1973-76.  The MGB and MGB GT ceased production in late 1980.

The MGB remained substantially the same throughout its eighteen year production run.  Whilst there were some changes to trim both inside and out, the drivetrain, suspension, steering and braking were not significantly changed during this period. 

Refer to the timeline in Appendix 1 to see the changes in the MGB during its production run.

Roadster or GT?

Although the MGB did not change significantly during its life, different versions of the MGB may be more suitable to each persons needs.  The initial choice is whether to buy a Roadster or a GT.  Many owners now use their MGB’s as hobby cars, and accordingly the roadster is the more popular and commands higher prices.  However, the GT is a more practical car, and to some people a better looking car.  The Roadster is more limited in storage space and the soft top takes longer to erect than modern sports cars, however it has the obvious appeal of a convertible during the summer months.  The hoods should be reasonably weather proof, assuming that the car has a good quality hood in good shape.  There is relatively little performance difference between Roadster and GT; however the enclosed roof of the GT does give it more of a “grand tourer” feel than the wind in the hair Roadster.  This decision really comes down to personal choice.

Chrome bumper or Rubber bumper?

The rubber bumpers were installed for the 1975 model year to meet US safety regulations, and to avoid making two different versions of the car, the rubber bumpers were used on all MGB’s.  The rubber bumpers do have the advantage of providing protection against minor dings, however they are extremely heavy and do have an effect on weight and hence performance.   The rubber bumper cars were also raised slightly to meet US bumper height regulations, which has a detrimental effect on handling.  This can be corrected through handling kits, but is important to be aware of.  The later rubber bumper cars (1977-80) are better equipped inside, and feature dual circuit brakes and slightly lighter steering thanks to changes in the gearing, which makes them a little easier to drive.

The chrome bumper cars have a more “classic” look about them and this is reflected in prices.  The earliest cars with the chrome grille (1962-68) are perceived as the most desirable, however they are more basic inside with non reclining seats, “packaway” hood, non synchro 1^st gears, and lack of a brake servo.  As the years progressed, these items were gradually updated, and accordingly the “late chrome bumper” cars of 1973-74 are generally perceived as second in the desirability stakes to the earlier cars.

The interior and exterior trim levels changed during the period 1962-74, with changes in seats, hood, wheels, grille and dashboard.  However, condition of a car is generally more important than these minor differences.  Virtually any part can be interchanged between models and improvements can easily be retro-fitted.

We would strongly recommend that you seek a model with an overdrive gearbox, as these make a difference to motorway cruising.  An overdrive gearbox can be retro-fitted to a non overdrive car, however it is not a particularly cheap operation.

It would be beneficial to drive several MGB’s when you are looking so you can gain a feel for the different versions.

MECHANICAL

The MGB is a very conventionally engineered car, with tough and well proven mechanical components.  Accordingly, most problems with the cars tend to arise through normal wear and tear rather than any major weaknesses in the design.

a) Engine

The engine in all MGB’s is the BMC “B Series” 4 cylinder engine.  The engine is cast iron in construction and is overhead valve with a capacity of 1798cc and a stated power output of 95bhp.  This engine had already been in production in 1500 and 1600cc versions prior to being enlarged to 1800cc for the MGB.  A number of minor changes were made to the engine during its period of production, however the list of items to look for is relatively similar for all versions of the motor.

The B Series is not a particularly quiet engine, and there will always be an element of tappet noise even on a good engine.  If you hear an engine that is totally silent, it may have had the tappets adjusted up to hide wear.  The oil pressure should read 50psi at 50mph in top gear as a minimum – most rebuilt engines will normally run at 60psi or above.  Check for any obvious leaks, and ensure the engine runs at correct temperature – MGB’s are not known for overheating and the gauge should read below the centre in normal running.  All of the normal checks should be made for blown head gaskets, which usually go between No 3 and 4 cylinders.   The engine should not use any significant quantity of oil nor should there be any blue smoke.  Wear in the twin SU carburettors can cause rough running, as can incorrect adjustment.

Parts for the B Series are all available, and rebuilding these engines is not difficult.  If you find an otherwise sound car with minor engine problems, do not let this put you off.

b) Gearbox & Rear Axle

The MGB was originally equipped with a four speed gearbox with non synchro first gear.  Overdrive became an option in 1963.  The gearbox was replaced with a new all synchro four speed box in 1968.  The first gear ratio was changed in 1974, and the following year overdrive became standard.

The gearboxes are relatively tough and with regular oil changes can do large mileages.  The early gearboxes can often have weak synchro on second and may be slightly noisy.  The later box does not generally suffer any major problems and should be tight and quiet in operation.  Ensure that the clutch takes up correctly and is smooth.

The rear axle originally installed was the “banjo” type, which was changed for the Salisbury “tube” type in 1965 on introduction of the BGT.  Regular oil changes will ensure a long life for this unit and there are no particular problems with it.  A slight clunking can indicate wear in the thrust washers, which is relatively simple to fix.

c) Suspension, steering, brakes

 The suspension on the MGB was derived from that of the MGA.  The key difference is that the B has a one piece front crossmember to which all suspension and braking components bolt, allowing it to be removed as one unit.  The front suspension is a coil sprung layout, with unequal length wishbones.  The upper part of the wishbone is formed by the lever arm shock absorber.  The rear suspension has a live axle with leaf springs, and lever arm shock absorbers.

The suspension system does not have any major vices, being strong and reliable.  However, any wear in the bushes, springs or shock absorbers will result in poor handling and ride.  There is a higher degree of body roll in the rubber bumper cars, but the suspension on all B’s should feel tight and precise with no rattles or knocks. It is important to ensure that there is not too much movement in the kingpins, and that the lever arm shocks are not leaking.  Beyond that, a drive of the car and check of components for wear should suffice.  All suspension components are available new, and many companies offer uprating kits that allow the fitment of telescopic shock absorbers, better suspension bushes and uprated springs.  The suspension on an MGB is not particularly difficult to work on, and an overhaul is well within DIY abilities.

The braking system is a conventional setup, with 10.7in discs at the front and 10in drums at the rear.  Originally there was no brake servo, however this was introduced as an option and was then standardised in 1974.  Retro-fitting a servo is relatively simple.  The brake master cylinder was changed to a dual circuit layout in 1976.  The braking system does not have any major faults, though the handbrake can take careful adjustment to ensure it is operating effectively and often the grease nipple on the handbrake cable can be forgotten.  Other than this, the normal checks that apply to vehicle brakes should be applied.

The MGB uses a Cam Gears rack and pinion steering system.  The gearing of the system changed from 2.9 to 3.5 turns in 1975, at which time a collapsible steering column was also introduced.  The steering is generally trouble free, but ensure it is nice and tight with less than an inch of free play in the universal joint and gaiters in good order.  Note that some people install larger wheels and/or larger tyres onto a B, which can result in very heavy steering – so check the wheel/tyre combination before you drive a car.

 

The bodywork is the most important factor to look for when buying an MGB.  As these cars now range from 27-45 years old, virtually all will have had some panel work done and some rust removal or paintwork.  The standard of care of the car and the standard of repairs performed will have a significant impact on how the car has lasted.  The body is the most expensive area of the car to put right and accordingly is the critical area to view when considering a purchase.

The MGB was the first MG sports car to have a monocoque construction, i.e. a single bodyshell with no separate chassis.  The bodyshell was somewhat over engineered, and is exceptionally strong and well constructed.  However, rust prevention was not as advanced as it is today, and accordingly it is important to ensure the car you are viewing is structurally sound.

The key area to check for corrosion on an MGB is the sills.  The sills run from the back of the front wheelarch to the start of the rear wheelarch and form the main structural strength of the car, and accordingly are very important.  The outer section of the sill that is visible from the exterior has within it a central membrane, with an inner box section inside that.  You should ensure there is no corrosion visible inside, outside or underneath the car in the area of the sills.  Note that sometimes minor rust bubbles visible at the front or back of the sill may simply be corrosion in the outer panels, which is not critical but should be attended to before it spreads.  However, this often cannot be determined without expert scrutiny, so treat any visible sill rust with suspicion.   If complete sill replacement is needed, the work should be carried out by someone experienced in this job, as correct alignment is vital.

Whilst you are inside the car checking sills, lift the carpets and ensure the floors are sound.  Also lift the carpets at the back of the cabin to check for any corrosion.   If possible, remove the battery covers (the batteries are located in metal cages below the rear floor) to ensure that the battery boxes have not corroded.  Note that until 1975 MGB’s had twin six volt batteries, and after that moved to a single twelve volt battery which resulted in the nearside battery box being removed.

The front wings should be checked next.  Look for corrosion at the base of the wing, in the seam where the wing joins the scuttle, and around the headlights.  Minor corrosion can also occur where the side trim strips are held on to the wing.  A useful check is to reach inside the inner wing near the back, where you will find a small ledge; the top of this ledge can gather road dirt and hence can corrode, so a check with your hand is worthwhile.

Remaining at the front of the car, check the bonnet.  Earlier MGB’s had an alloy bonnet, which can be susceptible to dents.  Also check the front valance, which can suffer from dings and minor corrosion.

Moving back, check the base of the doors and underneath the doors for corrosion and ensure the drain holes in the door bottoms are clear and free of rust.  Ensure the door fit is good and that the doors open and close easily.  Looking at the rear wings, check the wheelarches carefully and run your hand inside the rear wheelarch rim to check for filler or rust.  The seam at the top of the rear wing should also be checked.

At the rear of the car, check the boot floor for corrosion and also ensure there is no evidence of fuel leaks from the top of the fuel tank, which can corrode (look for fuel leaks or smells).  On GT’s there can be rust in the tailgate and roadster bootlids should be checked.  As with the bonnet, the bootlid on Roadsters was originally aluminium and was then changed to steel.

All of the exterior trim should also be checked for damage, though replacement of these items is relatively simple and not particularly expensive.

These are the main visual checks that should be completed on the body.  It is not unknown for less scrupulous owners to hide rust damage through the use of body filler, and in some cases the rust can be hidden from all but very experienced eyes.  Fortunately, most of these cars have now either been restored or have deteriorated to a stage where the rust is visible.  However, if you are in doubt we strongly suggest you consult with an expert.

The interior of MGB’s is fairly simple, and the good news is that virtually anything is now available.  Most cars will by now have had some form of retrim, so what you may see on a car may not be indicative of standard equipment.  It is however worthwhile noting that some MGB’s have had their dashboards significantly modified for extra instruments or switches – so check that you are seeing the original (refer to our pictures section). 

Make all the usual checks for worn seats, carpets etc but be aware that kits are available for retrimming and rebuilding seats, new carpets, door and side trim panels – in fact virtually everything.  So a tired interior may be used as a bargaining point in price for a car but should not put you off an otherwise sound car.

The MGC was in production for two years, 1967-69, and was essentially an MGB modified to take the Austin 3 litre “C Series” engine.  Whilst the car was a fine tourer, it was not such an out and out sports car as the MGB and accordingly was not widely accepted.  It is now a rare car, and commands significantly higher prices than the MGB.  Its main visual features are a bulged bonnet and 15 inch wheels.

In addition to the engine, the MGC also featured different front suspension and rear axle, but other than that is similar to the MGB.  Many of the checks noted in the MGB buying guide apply to this car.  However, the rarity of the car is such that if you are looking to buy one you will not have a significant degree of choice.  We recommend that you consult with one of the experts in our TECHNICAL section for further information.

The MGB GT V8 was in production from 1973-76 and featured the alloy Rover 3.5 litre V8 engine.  Other than the engine and minor gearbox and suspension changes, it was virtually identical to the MGB.  Visually, it has Dunlop composite steel/alloy wheels and V8 badging.  The checks on this car are identical to the MGB issues noted above, other than the engine.  The engine is not a significant concern in these cars as the Rover V8 is a well proven and reliable engine, though does require regular oil changes and the use of correct antifreeze to prevent corrosion of the engine.

Note that a number of MGB’s and MGB GT’s have been converted to take the Rover V8 engine, and this continues to be a popular conversion.  If you are viewing a car that has been converted, ensure you sight the vehicles LTSA Compliance Certificate and possibly consider an engineers inspection to ascertain the quality of the conversion work.

The MGB was an extremely popular car in America, and accordingly the majority of production was sent to the USA.  A number of these cars have since found their way to New Zealand, some of which have been converted to right hand drive.  HOWEVER!  It is important to be aware that from the late sixties, MGB’s for the US market had a number of ongoing changes to meet US emission and safety regulations.  This resulted in different interior and exterior trim, and most importantly emission control systems that gradually reduced power.  The later rubber bumper versions had a single Stromberg carburettor to replace the twin SU’s, and was so emasculated as to make a significant performance difference.  All of these items can be removed, but if you are looking at an ex-US market car it is worthwhile finding out which of these emission features are still fitted.

The MGB was in production for 18 years, during which time over 500,000 examples were produced.  They remain a popular car and are the most numerous model in the MG Car Club.  They are a relatively simple car, with excellent parts availability.  They are DIY friendly and are not difficult for a home mechanic to work on.  However, it is important to ensure that you purchase the right car to start with.  If you are looking for an MGB, we would encourage you to talk to existing owners and come to an MGCC event to look at a variety of MGB’s.  This will give you an idea of the differences between the variants, and perhaps allow you to decide which would suit you best.  We would also encourage you to talk to some of the experts (refer to our TECHNICAL page for details) who can assist you further in looking for an MGB.  Whilst there are good cars out there, they can take a bit of finding! 

We wish you good luck in your search for an MGB and look forward to seeing you and your car at an MGCC event.

The MG Car Club has provided this information as a general guide to purchasing an MGB.  It should not be relied upon to detect all problems in an MGB and should be read in conjunction with an expert review of a car and/or a professional inspection.

TIMELINE OF CHANGES