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MG B Service Schedule & Costs

Every service item for the MG B — what needs doing, when, and what it should cost at an independent garage versus a main dealer.

MK1 (1962–1967)1.8 BMC B-Series
MK2 (1967–1974)1.8 BMC B-Series
MK3 (1974–1980)1.8 BMC B-Series

MG B service: key facts

Routine service items

These are the items covered in a standard service. Most garages include oil, oil filter and a basic inspection. The rest are typically checked or replaced on a schedule.

Service itemIntervalTypical cost
Engine oil and filter
Original handbook specified 6000 miles but modern specialist consensus recommends 3000 miles due to age of engine design and typical irregular use pattern of classic cars.
MK1, MK2, MK3
 3,000 miles or 6 months
£80–£120
Rear axle oil
Use SAE 90 gear oil. Check level annually as axle seals deteriorate with age. Wire wheel cars have different axle specification requiring correct oil grade.
MK1, MK2, MK3
 24,000 miles or 3 years
£35–£55

Major service items

These are the big-ticket items. Miss them and you risk engine or gearbox damage. The costs are higher but the consequences of skipping are much worse.

Service itemIntervalTypical cost
Gearbox oil
Use SAE 20W-50 engine oil or dedicated gearbox oil.
MK1, MK2, MK3
 12,000 miles or 2 years
£45–£70
Timing chain tensioner check
B-Series engine uses duplex timing chain with mechanical tensioner.
MK1, MK2, MK3 · Petrel
 12,000 miles or 1 year
£40–£60

Periodic maintenance

Items that don't need doing at every service but should be on your radar at the right mileage or age.

Service itemIntervalTypical cost
Brake fluid
Critical on older brake systems due to internal corrosion risk.
MK1, MK2, MK3
 2 years
£60–£90

Known issues to watch for

The most common problems reported on the MG B, ranked by severity.

dangerous
Structural corrosion compromising rigidity
The MGB monocoque construction uses steel prone to corrosion in structural areas including sills, floor pans, and bulkhead.
major
Excessive emissions levels
The BMC B-Series engine in MGBs consistently fails MOT emissions tests at 199.3 times the fleet average, the highest failure rate in the MOT statistical data.
major
Wheel bearing excessive play
MGB wheel bearings fail MOT testing for excessive play at 28.3 times the fleet average, with the trend worsening.
major
Suspension component excessive wear
MGB suspension components fail MOT testing at 50.4 times the fleet average with a worsening trend.

1 more known issues tracked. Check a specific car's history to see what matters for its age and mileage.

Check a MG B's service history

Enter a reg to see franchised dealer service records — dates, mileage, and work done at every visit.

Check service history

£6.99 · Full refund if no records found

Related

MG B service FAQs

How often should a MG B be serviced?

A MG B should have an oil service every 3,000 miles or 6 months, whichever comes first. Original handbook specified 6000 miles but modern specialist consensus recommends 3000 miles due to age of engine design and typical irregular use pattern of classic cars.

How much does a MG B service cost?

Costs vary depending on the service items required and whether you use an independent garage or main dealer. Independent garages are typically 30-50% cheaper.

Can I service a MG B at an independent garage?

Yes. Under UK consumer law, using an independent garage does not void your manufacturer warranty, provided they use parts meeting the manufacturer's specification and follow the correct schedule. However, independent services won't appear in the franchised dealer digital records.