BMW Drivetrain Parts for BMW 6 Series E63 (2004-2010)

Hands down - one of the best performance upgrades you can make to an E46 M3, E60 M5 or E63/E64 M6! With almost no downside you can make your BMW much quicker by swapping in a new ring & pinion gear set. The gearing used to be overlooked when planning modifications but the 3.85, 3.91, and 4.10 gears are now one of our biggest selling upgrades for the E46 M3! With a rear end gear upgrade you get the effects of adding horsepower but without adding any more stress to the engine or drivetrain. It's one of the best areas to get return from your modification spending. Using a shorter (numerically higher) gear ratio will give you better acceleration. The R&P acts as a torque multiplier, putting the engine into the power band sooner for each gear. There is an 6% increase in torque at the wheels with the shorter R&P. Want to make your car faster off the line or out of corners? Or avoid a downshift to pass on the highway? This is what you need.

The R&P can be installed on its own but for cars that have more than 60,000 miles it would be a better idea to rebuild the whole diff. The factory viscous limited slip units have a typical lifespan of 50-70,000 miles. We offer diff rebuilding with 3.85 or other gear options and you get a fully-rebuilt and serviced limited slip unit at the same time. Click here for our diff rebuild options.

3.85 Gearing Example: 2004 M3, 6-speed manual, 275/35-19" rear tires

Gear RatioGearSpeedRPM

40 MPH in 4th
3.62 4th 40mph 2,250rpm
3.85 4th 40mph 2,350rpm

70 MPH Cruise
3.62 6th 70mph 2,650rpm
3.85 6th 70mph 2,800rpm

5th Gear Speed at Redline
3.62 5th 175mph 8,000rpm
3.85 5th 165mph 8,000rpm

Why 5th? Because 6th does not have the mechanical advantage to get past wind resistance at these speeds - it is more of a cruise/overdrive gear. Using 5th for comparison purposes is much more relevant than having to take into account wind direction, resistance, grade, elevation, tire sizing, etc. These numbers are for comparisons among gear ratios only, not to determine what your M3 will top out at.

This item is the genuine BMW part and the ring & pinion set only. You will need to have this professionally installed into your existing differential. BMW does not supply differential rebuild parts (bearings, shims, plates, etc.) so only a qualified shop that is experienced in BMW diff rebuilding should perform this installation. We also offer built differentials and exchanges, click here.

This item fits the following BMWs:
2001-2006 E46 BMW M3
2004-2010 E60 BMW M5
2004-2011 E63 BMW M6

OEM part number 33108311351

Stock rubber flex discs allow for a slight amount of give, especially under heavy acceleration and, depending on the amount of force applied, could potentially tear or split. This slight flex/give can prevent instantaneous transfer of force to the wheels, making accelerations unpredictable, or even lead to your vehicle being stuck on the side of the track. To combat this, IRP's Performance Flex Disc was developed. Made of CNC machined aluminum, this flex disc won't actually flex, and the polyurethane bushings will only provide a enough give to dampen some vibrations and prevent damaging the transmission. This is perfect for high torque applications such a drag cars and dedicated track cars that want immediate response and long term reliability.

110mm Diameter

This item fits the following BMW Chassis: 
E60 M5,E63 M6,E63,E90,E92,E93 

GA6HP26Z Automatic Transmission
Automatic transmissions are reliable, shift smoothly, and can last without issue so long as they are properly maintained. Over time, the transmission fluid becomes thick and the filter becomes contaminated with small metal particles. This can cause excess wear, high transmission operating temperatures, and eventual failure. To prevent this we recommend changing your filter, fluid, and seals to ensure your transmission continues to operate flawlessly. We recommend filter and fluid changes every 50,000 miles. This kit includes the transmission filter, gasket and bolts.

This item fits the following BMWs:
E60 BMW 545i 550i 
E63/4 BMW 645Ci 650i  
E65/6 BMW 745i/Li 750i/Li 760i/Li 
E70 BMW 3.5d/dX, 4.8i N62
E71 BMW 50iX N63

Enhance Vehicle Performance with SPEC Clutch Kit

Upgrade your vehicle's performance with the SPEC clutch kit, engineered to efficiently transfer power to the wheels during high-performance driving scenarios. Prevent premature wear and slippage with this kit, offering a torque capacity of up to 456ft.lbs. When combined with the SPEC lightweight aluminum flywheel, experience rapid and efficient engagement.

Designed for a variety of applications including street, drag, autocross, road racing, pulling, rallye, and drift, this kit bridges the gap between stage 2 and stage 3, delivering enhanced drivability and engagement quality.

Key Features:

• Multi-friction disc with carbon semi-metallic and Kevlar
• 15-20% higher torque capacity than stage 2 clutches
• Double sprung hub with spring cover relieves for flexibility
• Heat-treated components for enhanced strength and durability

Experience increased acceleration, reduced turbo lag, improved mid-range torque, and decreased parasitic drag for increased crank efficiency with the SPEC clutch kit. Compatible with vehicles manufactured between 2006-2009.

GA6HP26Z Automatic Transmission
Automatic transmissions are reliable, shift smoothly, and can last without issue so long as they are properly maintained. Over time, the transmission fluid becomes thick and the filter becomes contaminated with small metal particles. This can cause excess wear, high transmission operating temperatures, and eventual failure. To prevent this we recommend changing your filter, fluid, and seals to ensure your transmission continues to operate flawlessly. We recommend filter and fluid changes every 50,000 miles. This kit includes the transmission filter, gasket and bolts.

This item fits the following BMWs:
E60 BMW 545i 550i 
E63/4 BMW 645Ci 650i  
E65/6 BMW 745i/Li 750i/Li 760i/Li 
E70 BMW 3.5d/dX, 4.8i N62
E71 BMW 50iX N63