Looks like a cone type posi that would be in a Buick, olds, Pontiac. Once the cone bottoms out they don’t work and have to be replaced with a new unit.

Now someone is telling me it’s a Bore Warner posi unit and a good machinist can rebuild it.  Hope that is true.

The cones are tapered, as is the case. As the cone/case wears, the cone bottoms out at the small end and no longer binds up to turn the axle. Removing the cones and having the small end turned back on a lathe MIGHT restore the ability to bind again, but the spring rates will be weaker, because of the longer span between cones. You may be able to obtain longer/stronger springs for that situation.

The other consideration is, where are all the filings from the cones/case wearing now ? Most likely the bearings are contaminated and worn too.
The cost to do this may be less than a new Eaton carrier assembly, but may not work as well either.
Finding an Eaton posi and rebuilding it for less than $400 isn't going to be easy, unless the clutches are still good. The clutch pack and rebuild kit will run ~ $300.

Chris P told me isn't really worth rebuilding a badly worn carrier anymore, when you can buy a complete, new, assembly for around $400. After doing some research on parts prices, I have to agree. I replaced the worn spider gears and clutches in the 12 bolt under the '66 and had another carrier that I robbed the parts out of. I now have a bare 12 bolt, 3 series case that is about worthless, as the cost to replace all the internals exceeds the cost of a new assembly.

Update on the posit.  It is the unit that came in the car back in Dec of 65,  Gears were changed to improve performance would be my guess as the change was form 3.08 to 3.55.  The posi unit was a unit supplied by Dana (Not Eaton) and assembled in the axel plant in  Warren MI  on Nov 26th 1965.  I changed the gear oil the other day. the teeth on the aftermarket gears showed a good and very little wear pattern.  Probably won't know how the clutches work until next spring.  I am checking with a Corvette posi rebuild plant that has been around a long time about a possible rebuild as that posi unit was also used in the 63-67 corvettes.

Do you test limited slip differentials the say way as other positraction carriers?

Bobs_Place wrote:

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The shop manual says the torque to turn one wheel is 40 ft. lbs., or more for used diff, 70 or more for new, that is with only one wheel off the ground and trans in neutral.

I tightened up the clutch pack on my axle, assembled without the spring pack and with one wheel up it turned somewhat easily. Posi still worked good. 

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 Looks like clutches are toast,  about 5Lb if that to turn the wheel.  Also looks like a needle in a haystack to find a clutch kit for my carriers.

Sounds like you may need to replace the carrier?

Or you could do nothing, won't heart to run it this way, it will just act like an opened diff.

If you decide to replace the carrier check and record the backlash before you remove the carrier assy.

Lost in the 60s wrote:

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Bobs_Place wrote:

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Sounds like you may need to replace the carrier?

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 Not with a clutch style. If cones, possibly.

He should be able to rebuild it, but it could get more expensive than an Eaton replacement.

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 Mitch

I hadn't read your post as it cam in while I was composing mine. Good that you found the clutches. 

That's all the details they gave. You'll have to call Corvette Depot

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