Good move with the 742 case, as it doesn’t have a crush sleeve to have to contend with. This makes setting one up relatively easy. If you get a shim kit before you start and some gear marking compound, you should be able to correct it yourself. One thing that does need to be checked first and foremost though is the run out on the ring gear and on the carrier itself. Usually, whining from an improperly set up ring and pinion is from the pinion depth being off by a few thousandths. You’re better off to go ahead and correct the situation before it starts to wear the pinion bearings from the extra loading. Once they wear enough for the pinion to start rocking a little with the depth off, it starts chewing the teeth pretty hard and things tend to go downhill quickly from there.
