The Twin Screw is the most efficient and reliable supercharger concept produced. The overwhelming majority of issues is not the result of normal wear but instead underfilling, overfilling or lack of oil, poor inlet filtration, overheating, excess boost or inoperative bypass valve. Rarely, if ever, is the failure due to worn or defective rotors gears, bearings or the case. Prior to sending your supercharger anywhere for servicing, you may wish to check out the Kenne Bell website “Supercharger Tech Info.”

1. “How to avoid and analyze supercharger problems?”
2. ”Supercharger oil and oil level recommendations?”
3. ”Supercharger gear noise.”
4. ”Low boost causes and cures.”
5. WARNING: How "Bigger" Non Stock Cams Can Lower Vacuum, Prevent the Bypass Valve From Opening & Destroy Your Supercharger
6. WARNING: "Hot Air" Underhood Exposed Filters & Kits ( (How They Can Damage Your Supercharger & Engine)



All Kenne Bell and Autorotor drives and pullies are manufactured and serviced by Kenne Bell.
As with superchargers, only original components are used in the remanufacturing of the drives.

The Twin Screw Kenne Bell / Autorotor
Kenne Bell has been servicing, repairing and re-manufacturing Autorotor superchargers since 1991. Kenne Bell was the exclusive manufacturer of the billet Ford, Dodge, Jeep and Miata Autorotor Supercharger Kits from 1990-2005.

Models include the 087, 1.33, 1.5, 1.7, 1.8, 2.0, 2.1, 2.2, 2.4 and 2.6L. The 2.3L was a “cast” aluminum case Kenne Bell supercharger engineered jointly by Kenne Bell and Autorotor for the 1999-04 Ford Lightning which later utilized the new Kenne Bell 2.6, 2.8 and 3.6.

In 2005, Kenne Bell introduced our own exclusive line of 2.1, 2.6, 2.8, 3.6 and 4.2L superchargers and kits. At that time, since Kenne Bell accounted for +90% of all Autorotor sales, Autorotor ceased production. Kenne Bell subsequently purchased the remaining supercharger parts inventory and is therefore able to service all Autorotor products with genuine replacement parts.

Replacement Parts
Only new factory original replacement Kenne Bell or Autorotor/Kenne Bell parts are used in the repair or remanufacturing of our superchargers. Cheaper bearings, seals etc. are never substituted.

Service Tools
These superchargers require special dedicated tools and gauges to disassemble, reassemble, test and adjust to factory specifications.
Rotor timing (female vs. male rotor phasing) is particularly important, as is gear lash.


Due to the very strict tolerances in a Twin Screw, never attempt to disassemble a Twin Screw Supercharger. Highly specialized tools are required to service the supercharger. These tools and fixtures are designed by our engineers and then custom manufactured by Kenne Bell. They are not commercially available.

Kenne Bell Supercharger Kits
100% of Kenne Bell Superchargers were sold as an integral part of a Kenne Bell kit. The overwhelming majority (99%) of Autorotor/Kenne Bell and Whipple (mostly truck) kits were also sold as complete kits with inlet and discharge manifolds, intercooler, bypass valve etc. All these associated components are an integral part of the kit design. You may wish to include them to determine if any are responsible for a supercharger issue. There is no extra charge for cleaning and inspection. Kenne Bell designed the kits, so we know them best.

For example: An inoperative bypass valve, compromised or inefficient filter, incorrect oil level, “hot air” underhood filter, inlet air leak etc. can result in supercharger failure or damage. Again, we have the most experience with the kits as we designed them.

Supercharger Test Dyno
Only Kenne Bell possesses a supercharger dyno capable of testing up to 400HP of supercharger power consumption and 2000HP/3000 CFM with a dedicated non electric gasoline engine. See website.

Reman Policy
Upon receiving the supercharger, all kit components are thoroughly inspected.
You are then notified of our findings and the cost of repair before any work is performed.
If you decide against repairing the unit, there is no cost for inspection.
There is no waiting for parts from outside vendors to arrive.

All replacement parts for Kenne Bell and Autorotor superchargers and drives are in stock.

Repaired units carry a 1 year unlimited mileage warranty on defective materials and workmanship.

Shipping Repair Warranty
1. Always include with supercharger when shipping for repair or warranty:
     Repair request form
     RA (return authorization number)
2. Do not just throw the kit into a box without adequate protection.

UPS and FEDEX tend to “throw the box around.” Remove the bypass valve and pack separately as it is the most susceptible to breakage during shipping. Be sure to insure package with shipping company.

Return Shipping
The supercharger and/or associated components (assembled or disassembled) are wrapped in plastic and then surrounded by a protective foam packaging that protects against shipping damage. A tracking number is available for return shipments.

Liquid Cooled (Conversions, Testing)
Most Kenne Bell Superchargers can be updated to Patented LC (liquid cooled) versions.
Note: Autorotopr units were never available with the LC option. All LC superchargers are liquid pressure checked at 50 psi and rotated on special test fixtures after assembly.


Model Nos.
The model no. is stamped on the side of the front bearing plate located between the front cover and rotor case.


Repair Request Form click here