Many of us discuss what a true ‘drivers’ car should be, most say that 3 pedals and driver input via the gear shifter is an absolute must. Some say that the transmission doesn’t make a difference and that automatic gearboxes such as the DSG (direct-shift gearbox) will offer a similar driving experience, if not better.

Let’s delve deep into what makes the VW / Audi 6 Speed Manual Transmissions stand out from the rest whilst also looking into the flaws and limitations.

02M Gearbox

During the late 90s and the early 2000s, the VAG (Volkswagen / Audi Group) engineers designed one of the most well known 6 Speed Manual transmissions in the world, found on transverse mounted vehicles such as the VW Mk4 Golf, Audi A3 (8P) & TT (8N), Seat Leon (1M) and many more.

A compact ‘short’ 6 Speed gearbox with 6 forward gears for vehicles with transversely mounted engines, utilising two output shafts and one input shaft available in both FWD and 4WD versions and operated by two selector cables direct to the gearshifter.

The MQ350 02M 6 Speed Gearbox was first introduced from 2001 onwards and released into production vehicles such as the Mk1 Audi TT, VW Golf Mk4, the most well known high performance vehicle at the time was the 2002 Mk4 Golf 3.2 VR6 R32, a 4WD 6 Speed Manual Transmission with a 10 Bolt Flywheel, other models such as the 1.8T and 1.9 PD TDI used the standard 6 Bolt Flywheel. The 02M was later improved and produced as the 02Q box found in later Mk5 / Mk6 Golf Platform vehicles and even the Mk7 MQB Platform, the term ‘MQ350’ covers both 02M and 02Q Boxes whereas ‘MQ250’ refers to the earlier 5 Speed Transmissions such as the 02J, 02A and 02R.

[PHOTO OF MK4 GOLF R32]

The USA market only offered a 5 Speed 02M gearbox at the time creating a gap in the market for 6 speed conversions for the Mk4 Golf / Jetta 1.9 PD TDI fitted with ALH or BEW Engine Codes. This is where we stepped in and started offering complete 02M 6 Speed Manual Conversion Kits shipped to the USA & Canada, and we still do to this day!

Later down the road the 5 Speed 02J-B was released in the Mk5 & Mk6 Golf Platform vehicles where we decided to step in again and offer complete 02Q 6 Speed Manual Conversion Kits.

We have found throughout the year that the 5 Speed MQ250 Transmissions don’t handle the increased power as well as the 6 Speed. Advantages offered come in the form as better driving comfort, lower fuel consumption, increased strength under load and much more.

Standing out from the rest, the 02M gearbox steered away from the conventional gearbox design and instead opted for two output shafts each transferring power to the differential depending on what gear is selected. TW1 operates from gears 1 to 4 whilst TW2 operates 5th, 6th and Reverse.

02Q Gearbox

From first glance the 02Q gearbox shares many characteristics with the 02M, however looking closer there are differences in the construction. One of the most noticeable changes would be the end casing, most 02M gearboxes used an aluminium end casing meaning that the gearbox casing had to be split to access the input shaft, there are some later versions of the 02M and all 02Q’s which use a plastic end cap. This allows you to access the input shaft for shimming, shortening the overall labour time.

Another difference which sets the 02M and 02Q apart comes down to the shift forks, the 02M’s and earlier 02Q’s were typically constructed from segmented shift forks and some models used plastic shift fork sliders, both of these components became a problem and soon were revised by VW using Single Piece Shifter Forks and Bronze Sliders, we offer both on our website.

Upgrades and Servicing

With the 02M and 02Q Gearboxes, there are no hard limits as to when to upgrade the components.
Breaking forks / shifters happens at any power when driven aggressively. 4th Gear can strip on cars with 400ft/Lbs+, and LSDs are a must with any performance car to get the power down.

It is popular on the 1.9 PD TDI engines to convert the DMF (Dual Mass Flywheel) to a SMF (Single Mass Flywheel) & Clutch Kit for a more aggressive bite and to hold increased amounts of torque when paired with a Sachs Race Clutch Kit.

One the most popular and the easiest upgrade for the 02M and 02Q gearboxes would be our Stainless Braided Clutch Line, we also offer a Clutch Line for LHD vehicles.

When assembling clutches it is important to use the correct Clutch Alignment Tool as well as replacing the correct hardware such as the 02M Bellhousing Bolts / 02Q Bellhousing Bolts and even down to using the correct pressure plate and flywheel bolts.

02M Differential Upgrades

In regards to Plated vs ATB Diffs, if you are running mainly road and just some track, stick with the ATB as they require zero maintenance. If the car is mainly track, with only occasional road, the extra for a Plated Diff is worth it all day long. There is a night and day difference even compared to an ATB and a completely different world to an Open Diff.

We previously had a plated LSD fitted in our Mk5 Golf Track Car and we currently have one in the Audi S1 Project.

Audi S1 - CWZA 2.0 TFSI - PRY 6 Speed Manual

VW Golf Mk5 - CUAA 2.0 16v CR - JLT 02Q 6 Speed Manual - 283bhp & 400Ft/Lbs

In regards to service intervals, we plan to drop the oil every couple of races (so you could do every few 1000 miles) and if there is any sign of plate material, rebuild it, but we don't expect to have to rebuild it until the end of the season.

We can supply the Rowe Hightec Racing Differential Gear Oil 75W-140 LS and every single part of the internals is available separately if required.

• Quaife 02M 2WD ATB Helical Limited Slip Diff / LSD 
• Quaife 02M 4WD ATB Helical Front Limited Slip Diff / LSD 
• Gripper Plated LSD / Limited Slip Differential for VAG 02M 6 Speed 
• Gripper Plated LSD / Limited Slip Differential for VAG 02M 4WD 6 Speed

When pulling apart the 02M / 02Q Gearbox you’re going to need to renew the oil, we’ve always recommended Genuine OE Oil - G052527A2, a total of 2.3L is required so you will require 3x 1L bottles.

For the 4WD 02M Gen 1 Haldex Cars we can also offer the Rear ATB Quaife LSD. Many 4WD 02M owners also opt in for the Rear Haldex YHW Powertrack Insert which offers 50/50 power output to the front and rear differentials.

When replacing / upgrading the differential we would also recommend replacing the Bearings and Shims, it is crucial to shim the Gearbox sufficiently and replace the Plastic End Cap.

The same applies for the 02Q Transmission, where we also have plenty of knowledge and parts available for the later MQ350 Gearbox.

• 02Q Darkside Single Mass Flywheel (SMF) & SRE Clutch Kit
• Quaife 02Q 2WD ATB Helical Limited Slip Diff / LSD
• Quaife 02Q 4WD ATB Helical Limited Slip Diff / LSD
• Gripper LSD / Limited Slip Differential for VAG 02Q FWD
• 02Q Bearings and Shims

Gearbox Casing Modifications

For both 02M and 02Q gearboxes, these are to stop the case flexing, and therefore allowing the gears to spread. 4th Gear is profoundly prone to this especially under stress which is why we recommend the 4th Gear Support. We manufacture a 02M 6 Speed Gearbox Reinforcement Plate, ideal solution for the weak cast transmission casing most common to be a problem in vehicles pushing high torque figures. We have found this problem is caused by high amounts of vibration being transferred through the gears. These vibrations can eventually lead to cracks in the casing and in worst cases, can break away completely leaving an exposed gaping hole in the end of the casing. Usually this destroys all the internals rendering the whole gearbox unusable and beyond repair.

Manual Shifter Options

For the Shifter, there are plenty of options to increase the overall driving experience from 02M Short Shifter / 02Q Short Shifters to complete short shifter units. Pairing a short shifter with Solid Shifter Bushes and Solid Linkage End Bushes will result in faster, more responsive shifts and reduce the chances of mis-shifts, essential in a competitive scenario.

 If you have any questions regarding your 02M / 02Q Gearbox or any work that you are interested in carrying out please feel free to contact us for expert advice.