Dave,
No balls busted here. It's an open discussion forum.
Can't see why you need to take into account the ring and pinion gears being directionally cut. If the gears are the same ratio then they should have the same directional cut and should operate the same.
Weight differences and suspension travel differences between front and rear may have something to do with it. But the same thing happens to IFS and solid axel, so I think Steve might be right here that torque steer might be the culprit. But then again wouldn't you get torque steer in the opposite direction when performing the test in reverse? This doesn't happen. The vehicle goes straight.
The fact you only get one reverse gear is irrelevant.
Not sure why this happens, but going to do some more research in the Sportage in 4 lo and 4 high especially this winter in the snow.
Logansportage <img src="/forums/images/graemlins/patriot.gif" alt="" />
that torque-steer you get is from having a straight rear axle and a 3-link + panhard suspension set-up. when you gas it going forward, the axle shaft turns against the tire, against the traction, forcing the pinion up, pulling against the top link, pushing against the lower links and compressing the suspension, effectively lengthening the panhard. torque-steer is feedback from the inability of the drivetrain to blast forward immediately and smoothly, twisting the body in the opposite direction of the driveshaft, effectively compressing one side of the suspension while extending the other side. this effectively lengthens one side (compressed) while shortening the other side. this put the rear axle at an angle to the frame and therefore, as it moves forward, it "steers" the vehicle.
now, in reverse, you have the exact opposite actions and an opposite reaction. the pinion is forced down, pulling on the lower links, pushing on the upper, but guess what? the upper is centered, so, it does not create any steering effects.
reason why ring and pinion directional cut needs to be taken into account when making a claim that driving on a front axle is a good idea because MOST front axles use standard rotation R&P's, which are weaker when driven on the coast side, which is where they are driven in a front set-up. driveshafts turn the same direction, if the front R&P is backwards, the gear teeth get the power placed on their backside.
the fact that you only get one reverse gear was just a point i was making as to the irrelevancy of this whole argument.
