E34 Driveline

 

Korman Adjustable Short Shift Kit

Let's you select the shifter throw that suits your needs

All E34 P/N 25250001

Automatic Transmission Chips

Raises your automatic transmission shift points to better utilize a modified engines power band. Shift firmness is also increased, aiding acceleration. Ideal for use with performance engine chips, exhausts, headers, cams, etc.

BMW Transmission ECU# P/N
535i M30 >11/88 0.260.002.050 126535200
535i M30 12/88-8/90 0.260.002.077 126535300
535i M30 9/90-8/91 0.260.002.150 126535400
535i M30 9/91> 0.260.002.226 126535500
530i >8/93 0.260.002.196 126530100
530i 0.260.002.309 126530200
540i 0.260.002.262 126540100
540i 0.260.002.321 126540200

Lightweight Steel Flywheels

Precision machined and balanced steel flywheel. 35% lighter for reduced inertia and more rapid acceleration. Sold on an exchange basis.

535i P/N 11220006

525i M20 89-91 P/N 11220325

Aluminum Flywheels-525i M20 (89-91)

Precision machined on the latest numerical control lathes to ensure highest possible accuracy. Constructed of high strength, heat-treated aluminum, with a steel friction surface retained by aircraft structural screws. The insert is stress relieved, blanchard ground, precision drilled, countersunk, and heat-treated. It is far superior to spray-on type friction surfaces and can be replaced when worn. Kit includes aluminum flywheel, flywheel bolts and anti-galling plate. Total flywheel weight is 8.9 lb.

525i (228mm) P/N 11121880K

Flywheel Bolts (always replace flywheel bolts when replacing the flywheel)

525i P/N 11220616143

Aluminum Flywheels-525i M50 (92>)

Weigh anchor! The factory dual mass flywheel weighs 27.6 lbs. The Korman Aluminum Flywheel weighs just 10.4 lbs. This reduction in rotating mass (17.2 lbs.) allows your engine to accelerate faster at all Rpm's. Our flywheel is precision machined on the latest numerical control lathes to ensure highest possible accuracy. Constructed of high strength heat treated aluminum with a replaceable steel friction surface. Kit includes aluminum flywheel, anti-galling plate, and special flywheel bolts. Compatible with the original factory clutch set.

E34 525i M50 (92>) (228 mm) P/N 11121900K

Sachs High Performance Clutch Components

We sell only quality SACHS clutch components. Heavy duty pressure plates feature increased clamping force for better performance with high horsepower engines, bigger tires, etc. The heavy duty light weight pressure plates feature the same increase in clamping force but the center plate, normally cast iron, is replaced with lightweight aluminum for even better performance. Heavy Duty Sport Discs feature a performance grade friction surface which is both riveted and bonded for greater strength.

BMW Heavy Duty Pressure Plate Heavy Duty Light Weight Pressure Plate Heavy Duty Disc Release Bearing
525i M20 2121999618 2121999574 2121268132 21511225203

Stock Clutch Kits

All new (no reman) kits include stock pressure plate, disc and release bearing.

Korman Manual Gearbox Rebuild

See additional information under Rebuilding; Transmissions

2 year/24,000 mile warranty

We rebuild your gearbox using only BMW original parts. Includes new bearings, synchronizers, seals, gaskets and labor.

P/N 232316XX

Differentials

Korman Standard Differential Rebuild

see additional information under Rebuilding:Differentials

2 year/24,000 mile warranty

Differentials with normal wear don't usually require the replacement of the ring and pinion gears. Our standard rebuild includes complete disassembly, through cleaning, close inspection of all parts, replacement of all bearings, seals gaskets, crush sleeve and lock ring. Includes meticulous attention to correct gear lash, gear contact, precise pre-load of bearings and exact torque specifications. We expect our rebuilds to last well over 100,000 miles. Note: UPS can pick up and deliver your differential at your door!

535i P/N 33126082

Korman 75% Limited Slip Differential Conversion

If you race, autocross, rally, do BMW driving schools, or otherwise tend to push your car to the limit, let us convert your 25% limited slip differential to 75% limited slip. Wheel spin is reduced or eliminated, improving track times significantly. Additionally, the reduction in internal slippage lowers lubricant temperatures, helping prolong bearing life. The conversion requires special machining at our facility, making it necessary for you to ship your differential to us for modification.

75% Limited Slip Conversion P/N 33126375

Quaife Automatic Torque-Biasing Limited Slip Units

Already used in Formula 1, IMSA, SCCA and Pro Rally applications, Quaife Automatic Torque Biasing Limited Slip Units are now available for your BMW. Quaife units utilize a gear driven mechanical process to direct power at an infinitely variable rate (as opposed to a fixed 25%, 40% or 75% rate) to the wheel with the most traction. Unlike the more complicated and fragile Torsen design and the BMW OEM clutch pack limited slip units which tend to transfer power abruptly, the Quaife units are simple and rugged in design and provide a very smooth power transfer between the two driven wheels. Quaife units have proven to make as much a one second per mile difference in lap times on road courses. We can provide you with the unit for your own installation, or install it here in our facility.

P/N 3314690xx

Optional Ratio Differential Gear Sets

"My first BMW, a 1964 1800 TISA four door sedan regularly beat the performance sport cars of its day in autocrosses: E-Jaguars, Lotus Elans, Corvettes, MG Twin Cams, Porsche Super 90's, and more than a few 911's! Along with very minor engine changes, a good suspension package, wider wheels and tires, and a close ratio gearbox, my most effective "speed secret" was the change to a 4.75 gear set!"

Ray Korman

see related information under TECH INFO: DIFFERENTIAL GEAR CHANGES

Korman Suggested Differential Gearing

BMW original gear ratio suggested ratio P/N
525i M20 89-91 5-speed 3.73 4.10  
525i M20 89-91 Automatic 4.10 4.45  
525i M50 All 3.23 3.46  
535i 5-speed 3.46 3.73 or 3.91  
535i Automatic >6/90 3.91 4.27  
535i Automatic 7/90> 4.27 4.45  
530 5-speed 3.07 3.46  
530 Automatic 3.15 3.46  
540 >3/94 2.93 3.25  
540 4/94> 2.81 3.25  

Call us for recommendations, pricing and more information on upgrading your differential.

© Korman Autoworks, Inc. 1998