98 Dakota, differential gear ratios

From : frank boettcher

Q: on a 98 dakota 3.9l magnum to change from a 355 to a 392 rear end is it a matter of changing the ring and pinion gears or does it require a complete axle assembly driveshaft frank .

Replies:

From : aarcuda69062

frank boettcher fboettcher@comcast.net wrote on a 98 dakota 3.9l magnum to change from a 355 to a 392 rear end is it a matter of changing the ring and pinion gears or does it require a complete axle assembly driveshaft frank ring and pinion only. .

From : scootter

dont forget the odometer correction. it will be about 9% off from correct speed. scott frank boettcher fboettcher@comcast.net wrote on a 98 dakota 3.9l magnum to change from a 355 to a 392 rear end is it a matter of changing the ring and pinion gears or does it require a complete axle assembly driveshaft frank ring and pinion only. .

From : tom lawrence

dont forget the odometer correction. it will be about 9% off from correct speed. nope - the speed comes from the rear abs sensor which is driven from a tone ring. speed is calculated by the computer taking the axle rpms and multiplying by a pre-programmed pinion factor which equates to the diameter of the tire. in short change the gear ratio all you want - you wont change your speedometer reading. change your tire size and youll have to re-program the pcm or install an electronic device to compensate. .