View Full Version : more info on 12 bolt posi


yru_buggin
Feb 17th, 00, 02:19 PM
When I jack up the rear wheels of my camaro I spin one wheel and the other spins, but in the opposite direction. What does that mean?

shelbyz28
Feb 17th, 00, 02:27 PM
Your posi could be burned out, or you don't have one, i think. Maybe somone can verify this

Athorn4941
Feb 17th, 00, 02:41 PM
you have positraction ur i come from where we have lots of snow so i know what posi is up here when you get stuck on snow one wheel will turn and the other will not. if you jack up the car you can tell its posi when you spin one wheel the other will spin the other way.

camaroguy
Feb 17th, 00, 02:51 PM
I have a 70 Z with a posi. If you jack the car up and it is in park or gear, you will not be able to turn you wheels. If you can, you do not have positrack. A posi will also put you in the ditch in the winter when you romp on it as well.

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67 SS
70 Z/28

Athorn4941
Feb 17th, 00, 02:58 PM
no matter what kind of differintial you had you should never be able to move the wheels by hand if in gear or in park

yru_buggin
Feb 17th, 00, 02:59 PM
ok, now i'm really confused. one person said the wheels should both spin the same direction with the rear jacked up- and others say they will spin in opposite directions. who's right?
I just bought this car so I'm in the planning($$$) stages right now.
Any help is appreciated.

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1970 chevy camaro

yru_buggin
Feb 17th, 00, 03:00 PM
ATHORN whats wrong then because I can spin them in park?

1st & 2nd GENGuy
Feb 17th, 00, 04:12 PM
If you want to end the confusion, do a burnout and see if you get two black marks!!!

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68SS ZZ4, 4sp T-10, 12 bolt, getting painted

78Z28, 330hp vortec, TH350, 10 bolt (just finished)

MarkM
Feb 17th, 00, 04:21 PM
Doing a burnout and spinning both tires doesn't necessarily mean you have a posi. When I put the big block in my car with the original 3.08, 8.2, open rear end, if I were to brake torqe the car it would leave a posi mark as far as I desired. I don't know why it did this, I was running just normal radial tires, but I took the rear out anyway in favor for a 8.5, 3.73 posi rear.

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68 468 700R4

EMMETT
Feb 17th, 00, 04:30 PM
A true posi both wheels should spin the same direction...limited slip will allow one to spin faster than the other when one is under more load than the other. If your wheels spin in opposite directions you dont have a posi...sorry

rickmack
Feb 17th, 00, 07:22 PM
Actually, my 12 bolt posi does let the wheels spin in opposite directions when the car is jacked up. I was told that the posi in my car (Eaton, OEM style) will only engage when I am driving the car and the car needs the posi. ???? I can't explain it, I just know it to be true....
Rick

Steve R
Feb 17th, 00, 10:16 PM
Emmett is correct, on a properly functioning posi both tires will spin in the same direction with the car jacked up. But the only way to know for sure it to take the cover off the rear end and look at the carrier.

Steve R.

camaroguy
Feb 18th, 00, 07:37 PM
Sorry guys I jacked up my 89 Iroc 350, my 70 Z/28 and 97 Z/28 and while they are in gear, the wheels will not turn by hand. I put them all in neutral and they turn in the same direction hence they all came with factory posi's.

big gear head
Feb 19th, 00, 08:40 AM
Rear end work is my business (big gear head). A posi that is set up right will cause both wheels to turn the same direction with the trans in N. When the trans is in P you should not be able to turn the wheels. The problem is that when the clutches wear, the unit loosens up and begins to act like a "open" or standard unit. In this case the wheels will turn in oposite directions with the trans in P. The only way to be sure is to remove the cover and look at it. If it has the preload springs, plates and clutches,it's a posi. If it is a posi and it is acting like a standard unit, you need to have the clutches replaced and the preload reset.

EMMETT
Feb 19th, 00, 09:41 AM
SETTLED!!