Question 1

What does a gearbox do in a car?

Accepted Answer

A gearbox is a gear assembly that allows you to change gear ratios between the engine and the wheels, adapting torque to driving speed.

Question 2

How does a car's drive work?

Accepted Answer

The drive is the system that transfers power from the engine to the wheels – depending on the type (FWD, RWD, AWD) it differs in the arrangement of shafts and differentials.

Question 3

What is the difference between a manual and an automatic transmission?

Accepted Answer

A manual transmission requires the driver to operate the clutch and shift gears, while an automatic transmission automatically adjusts the gear ratios to driving conditions.

Question 4

How do I check which gearbox fits my car?

Accepted Answer

The surest way is to check the gearbox code (e.g. on the data plate) or VIN number – this ensures full OEM fit.

Question 5

What symptoms indicate a drive problem?

Accepted Answer

Vibrations, noises when starting or jerking may indicate a worn universal joint or play in the drive shaft.

Question 6

Do BMW E90 gearboxes fit other models?

Accepted Answer

Some versions (e.g. 6HP19) are compatible with BMW E60 or X3 models, provided that the OEM number and drive type match.

Question 7

Is replacing the gearbox cost-effective?

Accepted Answer

Yes – used, proven gearboxes offer up to 60% savings compared to new ones, while maintaining full functionality.

Gearboxes and drives