Drivetrain Rear end rebuild

Discussion in 'Fox 5.0 Mustang Tech' started by 88vertgeetee, Feb 20, 2013.

  1. Hi I am looking to rebuild my rear end. Have a bad pinion bearing. I got a quote for 250 labor plus bearings and fluid. That's if the gears are still good. My rear has been vibrating for the last two weeks. Is there a way to tell if the gears are bad or am I just gonna be surprised when the mechanic pops the over?
  2. I'd buy new gears. If the pinion bearing is that bad the angle the pinion meets the ring if off.
  3. Sounds like a pinion bearing to me.
    I have had them go out several times on my business trucks/vans, and have yet to have anything else damaged.
    Hopefully you'll have the same thing.
    The price sounds reasonable.
    If you have been wanting a ratio change, now is the time.

    It's not terribly hard to swap a pinion bearing. You would just have to put everything back exactly as it was.
    If you are not changing the gear it's pretty straight forward.

    Another option I have used when the pinion bearing goes out and I don't have time to mess with it: Get a used rear, and put the other aside for a high quality buildup. Stang 8.8" rears with the limited slip still inside only run $100-200 around here, and way cheaper if you luck up on one at the u-pull.
  4. Did your mechanic put it on the rack and tell you the pinion bearing was bad?
    A bad rear u-joint has the same symtoms, and is far more likely on a car.
    My trucks go through the pinion bearings because they are Powerstrokes that tow day in, day out.

    If I was a mechanic looking to scam a quick 200 bux, I'd find someone with a bad u-joint and tell them that it was the rear. Then charge the $250 after replacing a $15 u-joint. Just sayin'...

    If your pinion bearing is bad, the companion flange will move up and down inside the front of the rear end.
  5. The price seems quite reasonable if you can just get the bearings and seal done. I do not know how you can tell if the gear is scored in the bearing area without popping the cover. Sorry. The good news is new bearings and seals can last a long time.
  6. I'm with Rate, it could be a U-joint. Definitely check that out unless you know for sure that the mechanic got it up in the air and pinpointed it to the pinion bearing.
  7. You aren't anywhere near Pensacola, are you?
    Long shot, I know...
    There are 2 GTs in the local u-pulls at this moment in time, and both had rears still in them a few days ago.

    I have a spare 8.8" out of a GT, but it's a 2.73 gear.
  8. Personally, based on the info i'm hearing, I'd pop-in a set of u-joints myself to see if that fixes it. Those are real easy for anyone with basic tools to knock-out and inexpensive parts -besides, they would probably need changing anyway if the rear is suffering. If that doesn't fix it, then I'd consider the other options.