my first 742 case rebuild, need alittle advice please
Sorry if this has been asked before and I am sure it has but bearings are expensive and only want to do this once, I have a 742 case, it came with NO shims, gears sure grip etc, I have a new set of Richmond 323 gears and a used cone type sure grip, and new bearings, I have plenty of tools, press, etc, I have installed new side bearings on the sure grip and need to install the pinion and set the depth, the manual I have ( written by Larry Shepard ) is pretty helpful but it says to use your old shim pinion gear marking and your new marking using a chart to decide on shims, but I don't know what the old number was, so I read through some old threads hear and most say with a 742 case start with a .090 shim and go from there, is this correct?, any other tips? thanks
for 742 cases if you do not have the original pinion shim start with the .090 shim for your initial set up ---
do not install the pinion seal until you do your final set up
install your pinion into the case and install the yoke and add some preload to the bearings to take up any slack in them
install your carrier and gear and set the backlash .006-.009
do a pattern check
if pattern is not correct,, remove pinion --- a shim change will have to be done - make shim changes in increments of .003 to see movement in the gear pattern
to move the pattern up on the teeth use a thinner shim -- to move pattern down use a thicker shim
adjust shim thickness until a proper pattern is found
once you have the correct pattern ,, start your final set up and select the right amount of shim to set the pinion bearing preload 20-30- inch/lbs rotating
with the preload shim selection is done -- do your final set up buy installing the seal and yoke and tighten the pinion nut --- check your pinion preload again
if correct then install your carrier and gear to set the backlash ,,, thgen tighten the cap bolts to spec. 90 ft/lbs
make sure all turns smoothly
once you have installed the diff into your car ,, do a proper break in for the bearings and gears .
