xDrive transfer box judder: diagnosis and oil service

Which cars are affected?

This page covers the transfer box on BMW xDrive all-wheel-drive cars. BMW’s technical guidance on transfer box judder, published in North America, covers G-series xDrive models, including:

• X3 (G01)
• X5 (G05)
• 3 Series (G20)
• 5 Series (G30)

We also diagnose the transfer box on older E-series and F-series xDrive cars. If you are not sure which model or series your car is, put the registration in the enquiry form and we will check.

For other BMW work, see our BMW and MINI specialist page.

What are the symptoms?

• jerking or shuddering when cornering at low speed
• jerking or shuddering when pulling away at low speed
• hopping or binding in tight turns

BMW describes the judder as coming with no warning light. When you book, tell us when it happens, for example on full lock in a car park, and whether any tyres have been replaced recently.

What causes it?

BMW names two causes for judder on G-series cars:

• Tyres. Tyres that are unevenly worn or of the wrong size.
• Transfer box oil. Factory-fill oil that is out of specification.

On older, high-mileage E-series and F-series cars, one parts specialist reports wear of the clutch pack and brittle actuator parts inside the transfer box.

How do you confirm the fault before fitting parts?

A fault code is not a repair, and a judder is not a diagnosis. Before we quote for any work, we:

• check the tyre size, brand, wear and rolling circumference on all four wheels
• read the fault data with our diagnostic equipment
• road test the car, including with the all-wheel drive switched off, as BMW’s test plan sets out, to see whether the judder comes from the transfer box

We then show you what we found and send a written price. No work starts until you give us your written approval.

What does the repair involve?

That depends on what the tests find.

Tyres. If the tyres are the cause, we tell you which tyres are the problem and send a written price. See our tyres page.

Transfer case oil service. Where the oil is the cause, BMW’s guidance is an oil change and a recalibration of the transfer box, followed by a period of driving so the clutch plates bed in. We carry out the oil change and recalibration in-house.

If the tests point to wear inside the transfer box, we explain in writing what we found and what the options are before anything else is done.

How long does it take?

It depends on what the tests find. Checking the tyres and road testing come first, and we tell you the result before any further work.

Before any work starts, you get a written price and a promised time for your next update. If the car needs to stay with us, ask about a courtesy car when you book.

Is there a recall for the xDrive transfer box?

Whether a recall applies depends on the individual car, so check your registration on gov.uk. Recall work is done by BMW’s network, not by us.