Gearbox Rebuild: How the Job Begins

In the photo, you can see a gearbox mounted on a stand in our workshop. This is how every gearbox rebuild begins. We've removed it from the car, cleaned it and got it ready to strip down. Now the real work starts.

When does a gearbox need a rebuild?

The gearbox whines or makes a humming noise – usually, it's the bearings.
Gears are difficult to engage, or one keeps jumping out of gear.
We find metal particles in the gearbox oil.
There are oil leaks that can't be fixed simply by replacing the seals.

How do we rebuild a gearbox, step by step?

First, we clean the outside of the gearbox so no dirt gets inside when we open it.
We strip it down, following the manufacturer's procedure exactly.
We inspect and measure the bearings, gears, synchronisers and selector forks.
Anything worn gets replaced with genuine parts.
We reassemble the gearbox with new gaskets, oil seals and bolts.
We measure the clearances and adjust them using shims.
We fill the gearbox with the exact oil specified for that particular gearbox.

Gearbox opened up at Das Auto Service, ready for repair

Why do we mount the gearbox on a stand?

The stand lets us rotate the gearbox safely and reach every side without knocking it against anything or risking dropping it. But it's not just about making the job easier. When we put everything back together, we measure clearances down to hundredths of a millimetre. At this stage, precision is everything.

What do we check after refitting the gearbox?

Once the gearbox is back in the car, we check the oil level, take the car for a test drive and listen for any unusual noises. We also keep an eye out for leaks.

With automatic and DSG gearboxes, we always carry out adaptation. Manual gearboxes don't need it, but we still check the clutch and make sure every gear engages properly.

Don't keep driving for long if your gearbox is whining or rattling. If a bearing breaks apart, it can destroy the gears and damage the gearbox casing. And that's when a repair turns into a much bigger job.

Advice from Kris Mladenov: If your gearbox only whines in a particular gear, remember exactly which one. That little detail really helps us track down the problem.

If your gearbox is whining, rattling or becoming difficult to shift, bring your car to Das Auto Service and let us have a look. We'll check its condition and tell you straight whether it really needs a full rebuild.