Genuine BMW BMW Differential and Gearing Upgrades

Servicing your rear differential at regular intervals is important to ensure you maintain both performance and a long lifespan. Over time, the differential fluid can break down, lose its lubricating properties, and become contaminated with metal shavings and debris. Regularly replacing the fluid ensures that the gears and limited slip differential clutch packs are adequately lubricated, reducing wear and tear. Regular maintenance also helps identify potential issues before they become major problems.

This kit includes Genuine BMW differential fluid designed specifically for your M Sport differential and a brand new fill plug. The factory plugs include a rubberized seal that compresses over time and may not seal properly when reused.

One unique aspect of performing this service is the removal of the lower differential temperature sensor. Unlike many typical BMW differentials, this differential does not use a traditional drain plug and instead uses the temperature sensor as a drain plug. This sensor is removed to drain the differential fluid and is replaced before refilling. If you'd like to replace this sensor as well (not included in this kit), please see our recommended items or search BMW part number 33107847469.

NOTE: This kit includes 3 500ml bottles of diff fluid. BMW claims that only 1 Liter of fluid is necessary, but we found that 2 500ml bottles were insufficient. The third bottle included also allows for a minor flush of the old differential fluid before refilling.

Used to create a seal on your differential where the axle shaft connects

Genuine BMW Shaft Seal With Lock Ring - 100X50X10
This item fits the following BMW Chassis:
E53 48IS,E38,E39,E53 X5,E63,E65,E82,E89 Z4,E90,E92,E93
 

Bushings tends to wear over time and split or even break free from the internal sleeve, causing excessive movement and sloppy control feel. Genuine BMW bushings are the perfect option to restore suspension back to day 1 quality.

As a leading source of high performance BMW parts and accessories since 1993, we at Turner Motorsport are honored to be the go-to supplier for tens of thousands of enthusiasts the world over. With over two decades of parts, service, and racing experience under our belt, we provide only quality performance and replacement parts.  All of our performance parts are those we would (and do!) install and run on our own cars, as well as replacement parts that are Genuine BMW or from OEM manufacturers. We only offer parts we know you can trust to perform!

Genuine BMW Rubber Mounting Rear -
This item fits the following BMW Chassis:
E83 X3,E85,E86,E89 Z4

This factory finned differential cover bolts directly to the E30 diff housing. This is a must for track cars with limited slip differentials. The clutch packs in these diffs generate a lot of heat, the more heat you can dissipate the better. The fins on this cover will do just that. This is an inexpensive upgrade that may save you a lot of money down the road. Plus it looks cool.

Kit includes cover, gasket and all necessary hardware.:

• 1 x 33112228335 - Differential Cover
• 1 x 33111210405 - Differential Gasket
• 2 x 07119914114 - Bolt
• 4 x 07119921522 - Bolt
• 2 x 07119921541 - Bolt

The following photo of the cover with bushing is just representation of this kit. 

This item fits the following BMWs:
1984-1991 E30 BMW 325e 325es 325i 325ic 325is M3

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