- JHM 4:1 Center Diff Upgrade SHIMS ONLY for 01A Manual Transmission
JHM 4:1 Center Diff Upgrade SHIMS ONLY for 01A Manual Transmission
For Manual Transmissions Only
NOTE: PROFESSIONAL INSTALLATING HIGHLY RECOMMENDED. WE ARE OFFERING THESE SHIMS SEPERATELY DUE TO DEMAND. THESE SHIMS DO NOT COME WITH A WARRANTY UNLESS YOU PURCHASE OUR 4:1 DIFF UPGRADE DUE TO THE INCREASED CHANCE OF INSTALLATION ERROR.
NOTE: THESE SHIMS ARE PRECISION MACHINED AND HARDENED AND EXCEED OEM QUALITY. USING STANDARD WASHERS OR SHIMS YOU FIND ON THE INTERNET IS A SURE WAY TO DESTROY YOUR EXPENSIVE DIFFERENTIAL.
The factory torsen center differential in the S4 and A4 provides a 2:1 torque distribution between front and rear. What does this mean? This enables the end of the car that still has traction (most of the time the rear) to deliver double the torque to the tires with traction. Our experience has proven that this closer to even distribution is best for drag racing. So this modification is not for you if you are into drag racing primarily. However for Auto Crossers, Road racers and others who prefer the twisties JHM recommends a bias ratio of 4:1. This is the same bias ratio that Audi has provided in the stock RS4 driveline.
So if you are tired of going through corners while using a lot of throttle and still getting "understeer" then this product is for you and will help you get a little more "oversteer" and allow you to drive the car a little more like a RWD car but still have the superior control of AWD.
To help make the proper selection below use this chart.
01E - 6-speed EARLY OEM PN 01E409751E = B5 S4 (all), C5 A6 (all), C5 Allroad (all) - See note above regarding older 01E diffs (pre 2000) that may not be fully modifiable.
01E - 6-speed LATE OEM PN 01E409751F = B5 S4 (all), C5 A6 (all), C5 Allroad (all), B6 A4 6-speed (02-03 3.0l V6 only all other 6-speed A4s have the 02X) - See note above regarding older 01E diffs (pre 2000) that may not be fully modifiable.
0A3 - 6-speed OEM PN 0A3409751B = B6 S4 (all) and some 05.5 B7 S4s (note: we have seen some 05.5s with the T3 diff which is already a 4:1 and does look different than the one in the picture above. If you have that diff there is no need to send it in for modification)
02X - 6-speed OEM PN 02X409751A = B6 A4 (04 and up) and B7 A4 (all).
01A - 5-speed = B5 A4 (99.5 and up) and B6 A4 02-04 with 5speed transmissions . NOTE: We do not modify the older A4 diffs, see picture below for more info. Also we only modify your diff and do not supply cores on these diffs due to the higher failure rate on these units.
--Here is a write up on how to perform the install on a B6/B7 S4. It will help with other models since the general idea is the same. Check it out --> HERE
--Here is a new write up on how to perform the install on a B6/B7 A4 with the 6-speed 02x transmssion. It will help with other models since the general idea is the same. Check it out --> HERE
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|2.8l V6 30v
By Purchasing any Off-Road use ONLY products from JH Motorsports, Inc. I acknowledge and understand the following disclosure. (This notice is located at the bottom of the page description of affected products on our website.)Vehicle Code § 27156:
(b) No person shall operate or leave standing upon a highway a motor vehicle that is required to be equipped with a motor vehicle pollution control device under Part 5 (commencing with Section 43000) of Division 26 of the Health and Safety Code or any other certified motor vehicle pollution control device required by any other state law or any rule or regulation adopted pursuant to that law, or required to be equipped with a motor vehicle pollution control device pursuant to the National Emission Standards Act (42 U.S.C. Secs. 7521 to 7550, inclusive) and the standards and regulations adopted pursuant to that federal act, unless the motor vehicle is equipped with the required motor vehicle pollution control device that is correctly installed and in operating condition. No person shall disconnect, modify, or alter any such required device.
(c) No person shall install, sell, offer for sale, or advertise any device, apparatus, or mechanism intended for use with, or as a part of, a required motor vehicle pollution control device or system that alters or modifies the original design or performance of the motor vehicle pollution control device or system. Health and Safety Code § 43000:
43001. The provisions of this part shall not apply to:
(a) Racing vehicles.
As the aforementioned code sections outline, it is against the law to operate or use a vehicle on public streets or highways with modified, altered, or disconnected motor vehicle pollution control devices. This may include but is not limited to, Evaporative Fuel Controls, Catalysts, DPF, PTOX, PCV Systems, Exhaust Gas Recirculation Systems, Oxygen Sensors, Thermostatic Air Cleaners, Air Intake Systems, Fuel Injectors, Regulators, Adjustable Cam Gears, ECU Programming, Mapping, or other Computer Modifications. Air Pumps, Air Injection, Timing, and any other Emission System Modification(s).
Purchaser acknowledges and certifies to JH Motorsports Inc., that Purchasers vehicle will only be used for racing applications or off road vehicle use only. Purchaser requests these modifications for the purpose of enhancing the vehicle for competitive Racing Applications and will not use this vehicle on public streets or highways. Purchaser agrees to indemnify JH Motorsports Inc., all employees, officers, owners, and subsidiaries for any civil or criminal liability arising out of use of Purchasers vehicle on public streets or highways as Purchaser has been duly notified of the laws and regulations regarding disconnecting, alteration, or modification of a vehicle’s pollution control devices. Purchaser understands and has been advised the driving of a vehicle on public streets or highways could result in criminal or civil penalties.
Warning: This product may contain a chemical known to the State of California to cause cancer, birth defects, or other reproductive harm.
Learn More: www.p65warnings.ca.gov