Truck Repair: differential slack, ford lariet, bearing preload

Question
Hello Van.
I have a '92 Ford Lariet.that I have owned about six years.It has always had slack in the rear end.A few years ago,I had it replaced with a used one,but the new one is just as bad as the old one.
I have been told the the only sure way to fix it is with a new one. For $1,700.00.
Years ago,I rebuilt an Adams winch,that had a differential in the braking system.I could adjust the lash in it by shimming the ring gear. I would like to know if it is possible to take the slack out of my pick-up in the same manner?
I know this isn't your garden variety sort of question,and I understand if there is no answer. But I thank you for your time.
                         Sincerly,
                             Jim

Answer
Hi Jim,
The slack can be adjusted on just about any of them, but the proceedure should be followed to get the proper tooth contact, bearing preload, and clearance. It requires the pinion, as well as the carrier to be adjusted, and means pulling parts in and out several times.
A manual is a must.
Good luck,
Van