E90 E92 E93 M3 DCT Gearbox Service

We regularly carry out DCT fluid changes for people wanting the 'lifetime' DCT fluid changed for peace of mind, and/or due to DCT oil leaks and DCT sump gasket leaks.

Owners often ask us "When should I change the Gearbox Oil in my M3"?

This is a great questions which is sometimes overlooked as every oil in the vehicle degrades over time as it picks up dirt from the mechanical gear wear process which naturally occurs on a minute scale. (This is why oil goes dark & dirty over time).

As enthusiast M-power drivers we are always servicing our engine oil, spark plugs, air filters, and diff fluid, but what about the gearbox oil?

BMW left it off the service schedule as they believe it to be a 'lifetime fluid' (as well as wanting to market the E9x M3 as an affordable vehicle to service & maintain).

However, with the common DCT leak issue which plagues the Lower Sump Pan, and Right Side Mechatronics Cover it's worth considering a DCT Service at least once in the vehicle's life.

We recommend the Gearbox (Manual or DCT) Service is carried out around 60,000 miles.

On all of our 4 options below our labour includes draining the old DCT fluid, removing the old DCT Sump, Gasket, & Intake Filter, installing the new DCT Sump, Gasket, & Intake Filter, filling with Millers XF Premium DCT Fluid, levelling off, and the important 'oil balancing' service function procedure via BMW ISTA software, all with picture evidence.
(Our prices also includes VAT).
The only difference is how many extra parts your vehicle requires, i.e. Gaskets, O-rings, PIpes (see below).

Some DCT Gearbox can be suffering oil leaks.
It doesn't take much of an oil leak for the Gearbox to get quite messy with leaking oil.
Most of the time it's just unsightly, but left for a while and it will cause low oil level inside.
A DCT Gearbox trying to operate on low oil level is a recipe for problems.
Early signs are nearly impossible to detect due to mechanical gear wear occurring inside the gearbox and therefore being invisible to the owner with no obvious early warnings.
Later signs are the gearbox overheating and the 'Transmission Temperature' warning shows.
In serious cases the M3 can go into 'limp mode' and refuse to change gear.

The common areas for the DCT oil leaks are:
  • Lower Sump Gasket
  • Right Side Mechatronics Cover Gasket
  • Left Side Oil Filter Cartridge
  • Left Side Oil Cooler Pipe O-rings
  • Mechatronics Wiring Loom O-ring
  • Thermostat to Water Cooler Pipes

We use Genuine BMW Parts to repair the DCT Gearbox oil leaks.

Then we clean the external gearbox to remove all traces of the old oil leak.
Then carry out the BMW ISTA Service Function 'Oil Level Balancing' which is paramount to obtaining the correct oil level as it electronically opens the DCT Oil Cooler Circuit to allow accurate gearbox filling.
This has to be done by advanced software like the Genuine BMW ISTA system which we use in house, and just as importantly needs to be carried out with the gearbox below a certain temperature threshold whilst monitoring the live data to ensure the gearbox doesn't go over it's required temperature during the service function as that will automatically abort the operation.

We offer 4 forms of complex BMW DCT work.

We've put together prices below to show the options available as it can be cost effective to change some components together at the same time due to the labour-saving effect of doing the job once rather than on two separate visits. 
That means just 1 workshop visit, 1 labour cost, and 1 set of oil needed.

  • Stage 1 keeps the Gearbox in the vehicle.
  • Stage 2 requires the Gearbox to be lowered but ultimately remains in the vehicle.
  • Stage 3 requires the Gearbox to be fully removed from the vehicle.
  • Stage 4 requires the Gearbox to be fully removed from the vehicle.




DCT Service (Stage 1)
Gearbox: Remains in vehicle.
For this repair work we supply & install the following Genuine BMW Parts & Millers Fluids:
DCT Lower Sump
DCT Suction Jet Pump
DCT Lower Sump Gasket
DCT Lower Filter Assembly
DCT Fluid (approx 6 Litres)






DCT Service (Stage 2)
Gearbox: Lowered but remains in vehicle.
For this repair work we supply & install the following Genuine BMW Parts & Millers Fluids:
DCT Lower Sump
DCT Suction Jet Pump
DCT Suction
DCT Lower Sump Gasket
DCT Lower Filter Assembly
DCT Fluid (approx 7 Litres)
DCT Right Side Mechatronics Cover Gasket
DCT Left Side Oil Filter Cartridge
DCT Oil Cooler Pipe O-rings






DCT Service (Stage 3)
Gearbox: Removed from vehicle.
For this repair work we supply & install the following Genuine BMW Parts & Millers Fluids:
DCT Lower Sump
DCT Suction Jet Pump
DCT Lower Sump Gasket
DCT Lower Filter Assembly
DCT Fluid (approx 7 Litres)
DCT Right Side Mechatronics Cover Gasket
DCT Left Side Oil Filter Cartridge
DCT Oil Cooler Pipe O-rings
DCT Oil Cooler Thermostat O-rings
DCT Wiring Loom O-ring






DCT Service (Stage 4)
Gearbox: Removed from vehicle.
For this repair work we supply & install the following Genuine BMW Parts & Millers Fluids:
DCT Lower Sump
DCT Suction Jet Pump
DCT Lower Sump Gasket
DCT Lower Filter Assembly
DCT Fluid (approx 7 Litres)
DCT Right Side Mechatronics Cover Gasket
DCT Left Side Oil Filter Cartridge
DCT Oil Cooler Pipe O-rings
DCT Oil Cooler Thermostat O-rings
DCT Wiring Loom O-ring
DCT Thermostat to Water Cooler Flow Pipe
DCT Thermostat to Water Cooler Return Pipe







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For any of the above 4 options we require your vehicle for 2 days to carry out this work.
This is due to the filling procedure needing to be done from cold which means depending on how warm the vehicle is on arrival we sometimes cannot carry out the filling procedure and/or oil level balancing service function until the next day.
Please see a screenshot from the BMW ISTA software below:

Please note, it's not uncommon for a vehicle to book in for a 'Stage 2' but when the vehicle arrives and is checked over we find the Mechatronics Wiring Loom O-ring and/or DCT Thermostat Pipe(s) leaking oil and therefore need to upgrade to a 'Stage 3' or even 'Stage 4'.
Therefore, please bear in mind that when it comes to oil leaks, your vehicle's requirements can sometimes change. If this is the case, we will provide pictures of our findings, as well as call you before going ahead with any additional work.

Please note, we often find other items which are problematic on the E9x M3 model like Gearbox Undertrays damaged or missing fixings or soaked with DCT oil leaks.
We also find bolts snapped off in the Gearbox Crossmember, as well as Exhaust Brackets missing. Please see the video below for an example of things we often find wrong.
We try to carry these items in our Parts Dept and if your vehicle needs additional work we will contact you to advise on any findings.



Please note, our prices quoted above include all Genuine BMW Parts and Millers XF Premium DCT Fluid. Should you wish to upgrade to Genuine BMW DCT Fluid please let us know at the point of booking (there is an additional £120 fee).

To make a booking with us for either of these 4 options, we require a £200 deposit at the point of booking.