Posi rear end

sup fellas so i picked up a posi 3.73 rear end finally for my monte carlo. Gonna replace the one it has in it now wich is a 2.29 open diff . Great on the freeway but not for the take off. My current set up is a 03 escalade 6.0 with a 750 holley and 1 3/4 headers other than that pretty much stock. For trans i have a th400 also stock so i wanted a rear end with better take off and of course posi. My question is what should i do to it as far as maintenance before i throw it under the car? Change oil? What oil would be the best for it.and how many qts

pontiacgp said:

I'd take off the cover to check the rear end, it may be a 7.625. I would also remove the axles to see what condition they are in where they ride on the bearing and I'd change the seals before re-installing them. As far as the oil goes it's a little over 2 quarts but just remove the filler plug and when it start to run out it's full. If you use synthetic most come with the additive but make it does. If you use conventional oil you will have to add the additive. I use Quaker State synthetic

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Yah im pretty sure its a 7.625 came out of a 87 ss i did take off the cover before i bought it to make sure but even the stamp on the housing was from a monte carlo ss 2TH

Qdub24 said:

I would also check to see if it has a posi/lsd. My '87 MCSS had 3.73 w/an open diff.

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It is dats y i opened the cover before i bought it

Tyler J said:

Make sure the vent isn't plugged! You don't want to get it under the car and 500 miles later have a seal go out from pressure build-up.

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Cool good to know cant be that much for a new one anyways

Pontiac455 said:

Its a cone type too. Better than the gov. lock time bomb. Most likely 28 spline axls as well. Good score mate.

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Really i didnt know they came with 28 spline i thought they was only 26 spline is so thats great