# Shouldn't my 455 with 12 bolt have a posi?



## 70455goat (Nov 5, 2007)

Hi all,

Hey, I have a question. I have an all original drive train: 1970, 455 cu in, auto, 12 bolt rear.

The car is very low geared. When I get on the freeway, it seems like I'm still in second at 60. I would have thought that the rear end would have a posi trac, but when I stomp on the gas at a light, the passenger tire lights up and leaves a single black mark. Nothing from the driver side tire.

Does this sound right?

Dale


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## Rukee (Feb 8, 2007)

It sounds like you have an open rear end. But if the cover has 12 bolts, I do believe they were all POSI units. Which would indicate either the clutch pack back there is worn out, or there is no friction additive(modifier) in the lube.
I would pull the cover off and check the carrier to verify it`s a POSI carrier, swap out the rear gear for one you can drive down the highway, then add the right additive. I use LUCAS products, they have the additive right in there. You should be able to put one tire in the dirt and the other on the pavement and spin both tires.


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