Quaife A.T.B. Limited Slip Differentials
for the Mitsubishi Eclipse and EVO 8


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Mitsubishi Eclipse Differentials:

Front Differential EVO 4-9 including RS and MR models $975
Front Differential 
90-99 (AWD and FWD Turbo models) $940.00
2000-2004 Eclipse GT and GS, 5 Speed and Sportronic $760.00
96-99 Eclipse Spyder NT 2.4
99-2003 Galant
2006-2007 Eclipse GS
2006-2007 Eclipse GT 6 Speed Only
Front Differential '95-99 Non Turbo
 (Chrysler built transmission)
Center Differential for '92-99 AWD Eclipse/GVR-4
From manufacture date June '91 and newer only.


Additional Parts Necessary:

Speedo Drive Gear 
(Required for all Quaife Front Eclipse differentials, EXCEPT 2GNT, 4G GT and EVO)
Differential Bearings (if your mechanic is a wuss, you will need these, 2 required for all front and center diffs EXCEPT for the EVO front diff) $38 each.



The Quaife Automatic Torque Biasing Differentials enable your car to launch harder and corner faster. How? By getting the power to the ground and powering both drive wheels under nearly all conditions, instead of just one. They are ideally suited to high-powered front-wheel drive systems with no adverse effect on the steering and are particularly effective in combating the effects of FWD torque steer. Quaife A.T.B differentials are also used as the center differential of all-wheel drive vehicles where optimum traction is required.


With an ordinary open differential, a lot of precious power is wasted during wheel spin under acceleration. This happens because the open differential shifts power to the wheel with less grip, along the path of least resistance. The torque capacity of the Quaife unit is increased or decreased by varying the helix and pressure angles of the gear teeth. The operation is automatic and the unit is a direct replacement with the stock differential. There are no clutch plates to wear out as in more conventional limited-slip designs.

The Quaife A.T.B., however, does just the opposite. It senses which wheel has better grip, and biases the power to that wheel. It does this smoothly and constantly, and without ever completely removing power from the other wheel. In drag-race style, straight-line acceleration runs, this results in a close to ideal 50/50 power split to both drive wheels, resulting in essentially twice the grip of an ordinary differential.


In cornering, while accelerating out of a turn, the Quaife A.T.B. biases greater power to the outside wheel, reducing inside-wheel spin. This allows the driver to begin accelerating earlier, exiting the corner at a higher speed. 

In launching an AWD car, when weight transfers to the rear, the front wheels spin. Even with a stock viscous limited slip this happens because the wheels will slip first before the viscous fluid heats up and provides additional clamping force. With the Quaife A.T.B. center differential the limiting is much more immediate and you will launch harder and more consistently.

The Quaife A.T.B. also controls loss of traction when the drive wheels are on slippery surfaces such as ice and snow or mud, providing the appropriate biased traction needed to help overcome these adverse conditions. The Quaife Differential provides constant and infinitely variable drive. Power is transferred automatically without the use of normal friction pads or plates seen in other limited-slip designs.

The Quaife unique design offers maximum traction, improves handling and steering, and puts the power where it is needed most. A definite advantage whether on the track or on the street.


The Quaife is extremely strong and durable and since the Quaife is gear operated, it has no plates or clutches that can wear out and need costly replacement. All Quaife A.T.B differentials have a lifetime warranty.

The Quaife is great for street driving or racing. Racers no longer have to put up with locking mechanisms or spools that tear the steering wheel out differential during ordinary driving, street drivers will have trouble telling it's there until pushing the carís limits.

The Quaife A.T.B differential has been proven in everything from SCCA Pro Rally to Formula 1. It provides autocrossers with such an advantage that it has become "required" equipment for a winning effort.




Quaife A.T.B. Differential Operation


The Quaife Limited Slip Differential is an Automatic gear-operated Torque Biasing differential. Sets of floating helical gear pinions (1) mesh to provide the normal speed differential action. (2) Center spring provides pre-load. In the event of a wheel slip, torque bias is generated by the axial and radial thrusts of the pinions in the pockets (3). The resultant friction force enables the driving road wheel and sun gear (4) to transmit a greater proportion of the torque. This effect is progressive, but at no stage does the differential lock solid. Hence the inherent safety of the Quaife Automatic Torque Biasing Differential.



DSM (90-99) Installation Tips


Installation requires requires removal and re installation of the transmission. Expect to pay between about $350 for this for a DSM (90-99). Installation of the Quaife differential into the transmission requires the transmission to be opened. Once opened, the stock differential lifts out. When reassembling the transmission, the differential bearing preload needs to be checked. There is a chance that different size shims will be needed. quaife-heightcorrect.jpg (26655 bytes)
Any transmission shop with the ability to change a stock differential can easily install a Quaife. We charge $160 to install a DSM (90-99) FWD Quaife and $200 to install an AWD Quaife (with the trans removed).

The stock front differential has the drive gear for the speedometer cast into the housing. You need to buy a speedo drive gear separate and press it onto the front Quaife differential. Heating the drive gear a little will make it slip on easily.  This is not necessary on an AWD center differential or on the EVO front differential.

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You will need to either transfer the differential bearings from the stock differential to the Quaife, or buy new bearings. We have successfully removed the bearings with out damaging them about 90% of the time. If you are not able to risk damage to them, buy new ones to be sure. quaife-gearandbearinginstalled.jpg (31320 bytes)
The number one reason people end up getting a Quaife differential in a FWD Eclipse. Wheel hop kills the stock diff. Once a piece of the stock little spider gears breaks off, the spinning diff housing droop kicks right through the bell housing and into the clutch. Ouch.

If you are making good power in a FWD Eclipse, you can get a Quaife before or after you make this mess.

Wheel hop in an AWD will break the spider gears in the stock center diff also. MOST of the time the broken gear pieces will stay contained with in the center diff housing. This gives you the option of welding it solid (cheap fix, loss in around town drivability)  or buying a center LSD. Again... before or after you break it if you are making big power and getting ANY wheel hop.

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Contact Road Race Engineering

13022 La Dana Ct. Santa Fe Springs, Ca. 90670
Tel (562) 777-1522     Fax (562) 777-1562

Last updated 6/10mw