So the 742 case in my Challenger has been a mystery for some time now. Originally it had 3.55 gears in it, they were pretty loud going highway speeds on the both drive and coast sides. I pulled it apart adjusted shims and, that made a difference on the coast side but not really on the drive side. I changed the ring and pinion and had a HELLof a time getting a good contact pattern and it just went together kind of funny. Fast forward to about 25 miles later and....got really loud so I climbed under it and could move the yoke all around. I pulled it out took it apart, threw the original 3.55 ring and pinion in the case because I believe the pinion on the other set of gears is machined incorrectly since there is .12" difference between them from the bottom of the large inner bearing to the surface the shim or the smaller outer bearing would ride. That was about the same .12" I could move the yoke in and out....not sure why it was ok 25 miles ago but, oh well. So...anyway....no matter what I did with the 3.55 I could not get the drive side pattern off the toe of the gear. Shims out...backlash back and forth...coast side is perfect...drive side...not so much, so of course when you drive it...its loud on the throttle and quiet on when coasting. The first size shims i tried was .040" and it's only has .010" in it now. This seems like a pretty big change to me and it did make a difference on the coast side... So my question is after I have wasted a half an hour of your time reading my ramblings is....Has anyone else ran into something like this? Could there be something in the case that is not right?
