MG B service: key facts
- Oil service every 3,000 miles or 6 months
- Gearbox oil: £45–£70 — don't skip this one
- 3 generations from 1962 to 1980
- 5 tracked service items across routine, major, and periodic schedules
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 item | Interval | Typical 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 item | Interval | Typical 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
|
Has this MG B been serviced on schedule?
Check the dealer service records to see if the work above was actually done.
£6.99 · Full refund if no records found
Periodic maintenance
Items that don't need doing at every service but should be on your radar at the right mileage or age.
| Service item | Interval | Typical cost |
|---|---|---|
|
Brake fluid
Critical on older brake systems due to internal corrosion risk.
MK1, MK2, MK3
|
2 years |
£60–£90
|
Buying a used MG B? Check its service history first.
A B with a patchy service history can cost you thousands in missed timing belts, skipped oil changes, and hidden neglect. We pull the franchised dealer records — every visit, every stamp, every mileage reading — so you can see exactly what's been done and what's been skipped.
£6.99 · No records found = full refund, zero risk
Related
MG B service FAQs
How often does a MG B need servicing?
A MG B needs servicing 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.
What 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 to 50% cheaper for the same work.
Is a MG B expensive to maintain?
Routine servicing starts from £80 at an independent garage, which is about average for this class of car. The bigger costs come from periodic items like timing belts, brake fluid changes, and transmission servicing. Keeping on top of the schedule avoids expensive failures.
How do I check a MG B's service history?
You can check any MG B's dealer service records online using just the registration number. The check retrieves every logged dealer visit, including dates, mileage, and work done, so you can see whether the schedule has been followed or if there are gaps. It costs £6.99 and you get a full refund if no records are found.