8 3/4 problem????

[1971scamp383]

i have all put apart my 742 case 8 3/4 to change the pinion and gear.....i have a complete instalation kit for the diff.....why i dont have a crush sleeve in the kit?? how do you adjust the pinion depth without a crush sleeve?

[70aarcuda]

742 cases do no use crush sleeves..they use shims...

[1971scamp383]

ok....i dont know if ill explain the right way..........ive all put together the pumpkin.....and when i tight the pinion nut at 240lb-ft it jam ...the yoke dosent turn anymore......i was told to tight the yoke nut to 240lb-ft...is it right??cuz when i tight it ...the diff doesnt turn....just like a to tight bearing!!! what can i do....thanks all!!!!!!!!!!!

[74fldart]

you have 2 different things to adjust when setting up the pinion gear, 1)    pinion depth  and 2)  pinion preload .  both are adjusted with shims . it sounds like you dont have enough shims    for the preload .

go here for more info  http://www.moparmusclemagazine.com/howto/155_0308_mopar_rear_end_gears_set_up/index.html

[1971scamp383]

so.....i just have to put some more shims at the last (small) bearing on the pinion and it will be ok???

[68_Val_Sedan]

no you need to remove some of the shims from the small bearing.... adding shims will only make it tighter when you crank on the nut ... the shims are under the race in the housing ... did you remove the race when you took it apart if not and you added shims to the undersdie of the race on the big bearing you will needto remove some shims from the front, and no it is not the exact same amount because the pinion was changed but it will be close

[1971scamp383]

ok....so if its too tight i have to remove a shim on the small bearing right?? adding shims will just make it much tighter????wow...i dont really understand why but its my first differential build and i have a lot to learn!!!!!thanks all

[68_Val_Sedan]

if you add shims to the under side of the bearing races it will move the brearing races farther apart, so when you torque the nut down, the pinion pulls the two bearings into the races tighter and won't allow them to spin, where as if you remove shims from under the race it moves the bearing races closer together (the big and little)  and allows more clearance in both bearings allowing them to spin.   

[1971scamp383]

ahhhhhhhhh...ok.....i understand now!!!!!sorry!!!  i didnt add some shims under the bearing races........i just put 2 little shims between the small bearing and the pinion edge...which move the bearings farther apart.....but in the kit i have 3 more shims that i can put there...so i think that im gonna put one other shim and see .....if its too tight again ill just put another shim.....and if its too tight again ill just put another shim....and if its too tight again i think that im gonna be in deep $h!t!!!!!!!