Rear end grinding noise 68 Shelby GT500

[Layne Murphy]

Can anyone help me diagnose a grinding noise in the rear end of my 68 GT500?  The grinding is associated with both left and right turns and can be felt in the car. No noise is heard or felt in a straight line. Any help would be great.

[shelbydoug]

I would first check the fluid level. Then the quality of the lube in there.

If you have a locking device in there such as a Detroit Locker or even a Traction lock it's highly likely that there is an issue with it.

You may bein need of a rebuild.

[The Going Thing]

It could also be your bevel/spider gears in the differential/ trac loc.

[gt350hr]

    Layne,
       You need to pull the diff and have it looked at. As noted in the first two responses , there is an issue that will not fix itself and continued use could cause more damage .
  Randy

[Harris Speedster]

Murphy,
Smart thing paying attention to l & r turns and noise being equal.
That trick works on front wheel drive cars real well, and rear wheel.

Sharp zig zag while driving, isolates noise of which bearing is bad in the wheels.
Sound changes while zig zagging.

So, does it make more noise under acceleration?
Or does it make a different noise under de- acceleration?
If it changes, then the issue may be the ring and pinion?

Worth checking, cause its easy.
John

[gt350hr]

     Probably not a bearing "YET" . It could be the cover of the traction lock (if equipped). No noise when not turning , bad noises when turning in either directions. You need to pull it before it self destructs while trying to figure it out it's broken.

[The Going Thing]

     Probably not a bearing "YET" . It could be the cover of the traction lock (if equipped). No noise when not turning , bad noises when turning in either directions. You need to pull it before it self destructs while trying to figure it out it's broken.

Exactly. Much less expensive to replace the clutch pack than a carrier!

[pmustang]

Probably not your issue, but here is what I just had.

Had my whole rear axle sent out and went through with lots of work done. It had been making a noise before and still made the noise after. Very annoying vibration over 60mph or so.

After lots of head scratching and calling the rebuilder who was supporting me for a conclusion.....we found.....that a 67 rear flexi brake hose was installed and the part that connects to the axle tube was touching the axle shaft itself!!

A DOH moment it was.

Good luck with your finding of a solution

[Bigblock]

The grinding is associated with both left and right turns and can be felt in the car. No noise is heard or felt in a straight line. Any help would be great.

Did this just start or did you just get the car and it has this issue?

Does this also happen in reverse?

If also in reverse and you just got the car I would say someone put a Detroit L in it.

[gt350hr]

    X Ray vision hasn't been perfected yet , it needs to come out and be inspected.

[The Going Thing]

Pete: Some of the simplest things can drive one to a point of incredible frustration, often staring you right in the face! I don't make a habit of throwing tools but there have been a couple of those moments.

[The Going Thing]

    X Ray vision hasn't been perfected yet, it needs to come out and be inspected.

Randy: You didn't dial up a California psycho.. I mean psychic?  It's only a buck a minute.

[gt350hr]

   Guessing is just that. LOTS of well meaning guesses here but NOTHING can be done while it is in the car. Bite the bullet and pull it. It will not fix itself. Sheesh! "I see" a broken traction lock cover when I hold my hand up to the computer. I could be wrong and it's the spider gears that are bad. One or the other.
   Randy

[Relicdog]

Have you tried adding ( friction modifier ) may solve your problem.

[shelbydoug]

    X Ray vision hasn't been perfected yet, it needs to come out and be inspected.

Randy: You didn't dial up a California psycho.. I mean psychic?  It's only a buck a minute.

That bitch? I called her. She  answered, "you shouldn't have called me", then hung up.