Are there any aftermarket differential gearsets that would allow me to change the final drive ratio? My end goal is to reduce highway cruising rpm. any help would be appreciated. Thanks.

 

You just need to change your Transfer case, it is the final drive ratio, wich is lime a 4.30.


I want a 3.73 ratio, that would be awesome.

 

How or where would I go about doing that?

 

whats the gearing on the QUAIFE transfer case???????????????

 

1st - The factory ratio is not 4.30:1, it's 4.56:1

2nd - The final drive is not in the TC, the final drive is in the transmission. The ring and pinion in the TC is identical (ratio-wise) to the R&P in the rear differential. All the TC R&P does is reduce speed for the driveshaft, then the rear multiplies it back to the original speed. In the TC the ring gear is directly driven by a hollow spline coming out of the Transmission. That hollow spline is connected to the final drive in the tranny. The Ring Gear in the TC is attached to a differential that connects to the front wheels, one through the hollow splined shaft coming from the tranny to get to the driver's side wheel, the other goes out the other side of the TC to power the passenger side wheel. Since the front diff sits in the TC it reduces torque steer since the diff is nearly in the center of the car. The silly thing, which baffles me as an engineer, is that mitsubishi uses that ring gear in the TC to drive the pinion. For anyone that knows anything about gearsets they know that this is a no-no in geartrain design. The pinion is supposed to drive the ring, but does it backwards. This in turn places very high stress on the gears and generates a LOT of heat. That is why your TC has all those nice heat risers on the bottom to dissipate heat with the under car air. That is also why your TC will bite it if you don't put fluid on it. The fluid not only lubricates the gearset, but it also cools it. If you run no fluid it will overheat and wipe out in no time. What helps the gears to survive in this environment is the fact that the fluid is picked up by the ring gear and only has to travel a very short distance to lubricate the pinion, since the ring is rotating in the oposite direction it typically would in the rear. In the rear the fluid is picked up by the ring and has to spin all the way around before it lubricated the pinion. During that time a lot is flung off of the ring, etc. so less lubricated the gears. The TC gets a LOT of lube in the contact area between the gears, helping out a bunch. Oh, and the pinion that comes off of the TC Ring Gear has the viscous coupler in it for the torque split front and rear. Ok, I'm gunna stop now.

- Steve

 

HKS makes a final drive gear. Astroevo has it on his evo.

 

Link???^^^^^^^^^^^^^^^^^^^^

 

dude that woudl be awesome... can't find it on the hks website tho