It’s in my 10 bolt, but doesn’t work. Date stamped on carrier correct for the rear axel assembly date and car build date. Correct dates and casting #s for a gm 10 bolt from the factory for my car. CE code which is a posi for 66 chevelle, also has original posi tag on housing plug. Does not work.
gears were changed to Richmond 3.55:1 around summer of 1997.
-- Edited by jim larson on Saturday 2nd of November 2019 08:33:36 PM
-- Edited by jim larson on Saturday 2nd of November 2019 08:34:03 PM
-- Edited by jim larson on Saturday 2nd of November 2019 08:46:19 PM
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.
jim larson said
Nov 3, 2019
67ss wrote:
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.
Kind of odd as most all 66 chevelles came with Eaton units. I wonder if where they assembled the axels they had access to both bizzario and eaton units and temporary ran out of eaton units and stuck in a bizzario unit? I imagine they same plant assembled axels for all the gm models.
I heard some old-timers machinist could rebuild them. I will probably just continue to use as is unless I can find a eaton unit reasonable so with a rebuild I have less then $400 in it. At least that my hope.
jim larson said
Nov 3, 2019
Now someone is telling me it’s a Bore Warner posi unit and a good machinist can rebuild it. Hope that is true.
jim larson said
Nov 4, 2019
jim larson wrote:
Now someone is telling me it’s a Bore Warner posi unit and a good machinist can rebuild it. Hope that is true.
Disregard the Borg Warner, I interpreted a Guy on TC
Lost in the 60s said
Nov 4, 2019
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.
67ss said
Nov 4, 2019
This is about the cheapest I have found for posi units. They are made by Yukon gear. I ordered one of there complete kits with bearings and gears when I built the 12 bolt for my chevelle.
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 said
Nov 7, 2019
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.
jim larson said
Nov 8, 2019
Bobs_Place wrote:
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.
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.
It’s in my 10 bolt, but doesn’t work. Date stamped on carrier correct for the rear axel assembly date and car build date. Correct dates and casting #s for a gm 10 bolt from the factory for my car. CE code which is a posi for 66 chevelle, also has original posi tag on housing plug. Does not work.
gears were changed to Richmond 3.55:1 around summer of 1997.
-- Edited by jim larson on Saturday 2nd of November 2019 08:33:36 PM
-- Edited by jim larson on Saturday 2nd of November 2019 08:34:03 PM
-- Edited by jim larson on Saturday 2nd of November 2019 08:46:19 PM
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.
Kind of odd as most all 66 chevelles came with Eaton units. I wonder if where they assembled the axels they had access to both bizzario and eaton units and temporary ran out of eaton units and stuck in a bizzario unit? I imagine they same plant assembled axels for all the gm models.
I heard some old-timers machinist could rebuild them. I will probably just continue to use as is unless I can find a eaton unit reasonable so with a rebuild I have less then $400 in it. At least that my hope.
Now someone is telling me it’s a Bore Warner posi unit and a good machinist can rebuild it. Hope that is true.
Disregard the Borg Warner, I interpreted a Guy on TC
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.
This is about the cheapest I have found for posi units. They are made by Yukon gear. I ordered one of there complete kits with bearings and gears when I built the 12 bolt for my chevelle.
https://www.quickperformance.com/GM-82-10-Bolt-Posi-28-Spline-Limited-Slip-LSD_p_20353.html
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?
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.
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.
https://www.corvettedepot.ca/?route=product/search
Corvette Positraction Clutch Kit,
1965-1979
Estimated Ship Date 11/15/2019 (If Ordered Today)
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.
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.
Mitch
I hadn't read your post as it cam in while I was composing mine. Good that you found the clutches.
So Mitch, is this for a Dana unit or an Eaton Unit. Maybe it works in both? 10 or 12 bolt?
That's all the details they gave. You'll have to call Corvette Depot
TALK TO YOUR CORVETTE EXPERTS
877.600.8388
Mon-Fri 8-5:30 & Sat 10-3 EST
They are in Canada, so ask about shipping and tariffs costs...
I sent a questionnaire to them regarding the details. Not to hopefully; but maybe.