Ford uses a crush sleeve behind the pinion bearing . . . you should replace it with a spacer and shims.
Ah, the ole crush sleeve. A "cheap part" designed to “save time” when repairing differentials.
The crush sleeve is designed to be a one-time use part and looks like a piece of pipe that has been stepped on (sorta). I don’t like the one-time use aspect of it, for sometimes you must take a differential apart to re-shim a bearing or something - you must toss the new (but just barely used) part and install another new one.
This what the crush sleeve looks like in an FMJ differential (7¼” or 8¼”):
Ford and others are similar.
This is one companies (there are other companies, as well) fix for a crush sleeve replacement:
Ratech #4114 (works for both Chrysler 7¼” or 8¼” differentials).
If I was performing a “cheap” differential repair, just to get the car out the door – go with crush sleeve.
If you want the job done right (on the first time), and can withstand lots of abuse, and is re-useable – go with a crush sleeve retrofit shim kit (this doesn’t matter who made the differential). The above kit part number is only about $10-12 (US).
Technically, even removing the large yoke nut (for a pinion seal replacement or if the nut just came loose), you are required to also change the crush sleeve.
The crush sleeve is what is keeping the large yoke nut tight. If you had worked with a few of these before, you will say “that flimsy thing is keeping this large nut tight”? Sometimes – it doesn’t.
BudW