I am looking to buy a used rearend for my 93 mustang. The guy claims it has 373 gears and I know how to check the gear ratio but while I am in there is there anything else that I should check. What is the best way to check the posi trac? Is there a certain amount of play that should be between the hubs and the yoke? Also is $250 to much to pay for a complete rearend? Any information would be appreciated

 

250 SEEM OK ..JUST CHECK THE CROSS PIN WHERE THE BOLT GOES THOUGH MAKE SURE IT DONT ROCK BACK IN FORTH,,THAT S A PROBLEM AREA

 

If you can get the chance to see the fluid come out of it look for shaving and such. See if the clutch packs are wore out by being able to turn the whels opposite directions on purpose. If you can get a dial indicator, check the backlash to see if it's with .008"-.012". All I can think of right now.

 

make sure its good n' straight?

 

check all the welds where the axles tube meet the center section for cracks and such. to figure out the gear ratio if it isn't stamped on teh end of the pinion gear, count the number of teeth on both gears and divide the ring by the pinion to get the ratio. some typical counts are 39-11 for a 3.55 gear, 41-11 for 3.73, 35-9 for a 3.89, 41-10 for a 4.10