Gearbox Repairs

M32 / M20 Gearbox Services / Information / Repairs / Upgrades

M32 Gearbox Image transparent

WG Motorworks is please to be able claim that we are one of the best M32 repairers in the country. With hundreds of happy customers leaving us fantastic reviews local as well as driving far and wide! - having seen customers as far as Spain, France, Belgium, Ireland, Guernsey even sweden before!

Since 2010, when we carried out our first repair we have completed over 2000 of these gearboxes repairs / upgrades. Using all Genuine tools which we have invested heavily in, therefor helping us perform upgrades to GM specs, allowing us to perform a quick and efficient service. While also offering one of the best warranties on work carried out – 18months / 18,000 Miles subject to terms and conditions.

Using only the best components, bearing manufactured by Timken/SNR who are the leading bearing manufacturers to the automotive industry. We also stock all common replacement parts to ensure a swift service without any set backs or delays
While also using a high gear grade gearbox oil – Fuchs Titan Sintofluid 75w80.

Being such a common issue across the range of models / engines, we have listed as much information on this page as possible.

Our normal repair service is offered as – Drive in drive out, while you wait same day repair, which takes under 4 hours to complete. While Gen2 Retro fit service is still offered same day.

The M32 6 Speed Getrag gearbox is fitted to a wide range of vehicles, including Vauxhall, Fiat, Alfa Romeo and Lotus.

Bearings issues:

There is a very common problem with the M32 gearbox, the symptoms can vary and some complain of whining but no movement in the gearstick, whilst some complain of movement but no whining!

Generally this is what you should be looking out for:

  • When disengaging the clutch in 1st gear when pulling away, whilst holding the gear stick, it will move back into your hand, sometimes by 10-20mm! (the greater the movement, the worse the problem)
  • When applying the accelerator in 5th or 6th gear,  the gearstick ‘twitches’ in comparison to 3rd and 4th (although in rare cases there can also be twitching in these gears due to different bearing issue)
  • Whining sound coming from behind glove box area
  • Specifically on Corsa, Punto and Mito models; when turning right at 30mph+ you get what is best described as like a disc rubbing noise
  • Movement / whine more noticeable in 1st, 2nd, 5th and 6th gears

The gearbox problem which results in all of the above symptoms is a result of one bearing – specifically the bearing on top of 6th gear. The bearing rollers wear, which causes the movement in the gearstick, which is causing the internal gear shafts to ‘float’, and the whining is caused by pits in the bearings, which can be seen in the image below.

It is also quite common to get a constant whine in all gears from 20-30mph onwards, regardless of whether the clutch is engaged or disengaged, and which intensifies with speed. Often misdiagnosed as differential bearings, this is caused by pitted pinion bearings which can be seen on inner and outer races below.

The 2010-2012 gearboxes have seen more issues with pitted pinion bearings than earlier versions – this is due to GM changing the bearings to FAG and NGBC, as opposed to the earlier Timken bearings.

The Cause:

Bearing failure can be caused by a combination of things, mainly linked to poor gearbox design, excessive oil temperatures along with failure to change the gearbox oil (not part of the service schedule).

  • It is commonly thought that high torque output causes the bearings to fail on remapped cars etc. – but this simply is not the case. We have cars running 350-400lbft without issues, yet we can see low output engines (1.3 CDTI / 1.8 non-turbo etc) experience issues. It is true that the greater the power, the more heat will be generated, but a high percentage of the cars we repair are run-of-the-mill cars, which still run into gearbox issues. Essentially, doing long distances on the motorways, during which 95% of the time is spent in 6th Gear. Transfering the engines torque all the way down the input shaft, across to the 6th Gear (closest to the end on the output shaft), and then back down to the final drive put maximum load on this small top bearing.
  • The bearing which commonly fails and causes issues sits on top of one of the two output shafts on this 6-gear gearbox. Gears 1, 2, 5 and 6 are all on this shaft – hence why the issues typically manifest in these gears. Reverse and 3rd and 4th gear are situated on the other output shaft. In extremely rare cases we have seen issues with these gears instead, but this is only the case for >1% of repairs we have carried out.
  • When driving with the gearbox issue, we advise to use avoid using 5th and 6th and stick to 3rd and 4th gears mainly, as this will transfer the engines torque across the other output shaft, taking load off of the failing bearing.
  • It is also worth bearing in mind that failure can occur over time as well as mileage- if your car has failed with relatively low mileage, it could be down to the age of the bearings rather than the number of miles covered. It is equally possible that a high-mileage new car and low-mileage old car would fail.
  • If left unattended, the outer bearing race can start to spin, which causes the wear on the casing eventually popping out of 6th gear (stripping the gear) which can then finally punch a hole in the casing. Once this happens, it is highly unlikely that we will be able to repair your gearbox, due to the internal damage caused, making the repair uneconomical. Our advice is therefore to always catch the issue early, and book in for a repair as soon as possible in order to avoid further damage and associated costs.

Gear selection issues

Completely separate issue to the bearings mentioned above, and typically more common on the VXR / more powerful models due to the nature they are driven.

With selection issues most common on 2nd, 3rd and 4th issues to look out for are

  • Popping out of gear, once selected and power is applied the gear stick returns to neutral
  • Crunching when attempting to select gears, usually worse at high rpm
  • Poor gear change / Selection

The cause is typically down to wear and tear, mainly caused with more enthusiastic gear changes. The engagement teeth on the problem gear / hub wear down and lose their points becoming bured / rounded as seen below, if left eventually popping out will occur. Occasionally these issues can also damage the nylon fork guides, which then require replacement.


Generation gearboxes

Generation 1 – 2004-2013. Then Gen 1 Gearbox is the most common gearbox we see for repairs, with the main issue being related to 6th gear bearing, Few versions were made with bearing make change and guides added in 2010, however these did not resolve the problems. Installed with 55mm Top bearings.

Generation 2 – were released from MY12.5-MY2017 (2012 – 6 months in), although some cars were not installed with these until 2013+. These 2nd generation gearboxes come complete with improved oil galleries and, more importantly larger bearings (55mm vs 62mm OD, as seen below) with dramatically bearing surface area. But…..we still see these gearboxes in for repairs with the ‘All gear whine’ from pitted pinion bearings. The larger bearings help dramatically with the common 6th gear bearing issue – to date we have not seen a bearing issue bar a few light wear marks when in for pinion bearing repairs.

Generation 3 – MY17-Present With the 3rd Generation in the latest vehicles, with 3rd end casing consisting of different bearings again, however little information or parts are avaible currently.

Below is image of a Generation 2 casing (Left) easiest way to identify is the large gallery vein which can be seen running from the Center to top left, and lack of  oil filler / level bung on the lower left hand side, where then Gen1 has this located.



One popular upgrade we offer at the same time as our repair service is the 4H-Tech short shifters, with minimal labour charges if installed at the same time – 4H Tech Short shifts

We also have a range of Limited Slip Differentials (LSD’s) – LSD Options to maximize traction and dramatically improve handling , with minimal labour costs to install while the gearbox is removed.

Those looking to replace slipping clutches, or simply upgrade with more power in mind we have several options from OE replacement, or uprated friction plates / paddle clutches along with solid mass flywheel conversions. Please get it touch with you model / engine or search under Transmission upgrades on WG Motorworks Shop ,

6th gear ratio change – £90-£120 (+£80 If ECU cruise control programming required) Please enquire

Gearset ratio change –

Gearbox oil breather – From £150


Vehicle List - The 6-Speed M32 / M20 Gearbox is fitted in the following models (some may not be listed)

Mito 1.4 Turbo
Mito 1.6 CDTI