I've got an 84 Z 28. Do I have posi? If so, how much of what type of oil does it take?

 

You might, or you might not have posi. You might have a tag that tells you; but the absence of a tag doesn't mean you don't have one. Jack the rear wheels up and put the car in park (or in gear if it's a stick), turn one wheel; if the other wheel turns the opposite way, it's not posi; if the wheel is real hard or nearly impossible to turn, then it's a posi.

I would recommend synthetic gear lube, in a thin weight like 75W-90. If you're not sure, buy yourself a couple of bottles of the GM posi additive before you bust it open just in case. It will take most of 2 quarts of lube. With the synthetic lube, more of the additive seems to be necessary. Jut put both bottles of it in if you have one, then fill it the rest of the way with gear lube.

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"So many Mustangs, so little time..."
ICON Motorsports

 

i still like the pull the cover and inspect method of telling if you have posi or not ,plus you get a chance to look things over and change the gear lube.

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ICON Motorsports

1st & 3rd

 

If you have the HO engine, you should have 3.73 gears and a posi.

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82 camaro--original steering wheel, brake/gas pedals, seats--everything else modified
82camaro