The 1947 - Present Chevrolet & GMC Truck Message Board Network - View Single Post

70rs/ss · 08-28-2007, 01:55 PM

Yep, posi (12 bolt), clean that thing up!!! Use a couple of cans of brake cleaner in there to clean it up, once it is clean (and dry, that's why you use brake cleaner, as it evaporates with no residue). Buy Royal Purple or the like (Synthetic) in gear lube and add the GM posi addative (local GM dealer will have it). As for the ratio, there are two numbers stamped into the ring gear (big gear) it'll look like this: 56:98 (example only) divide the big number by the little and you'll get 4.11 or 3.73, etc etc as in 4.11 posi 3.73 posi. BTW was it a L6 motor? I have had several inline six trucks and they all had 4:11 posi in them.

08-28-2007, 01:55 PM	#2
70rs/ss Registered User Join Date: Dec 2004 Location: Northern AZ Posts: 7,270	Re: Rear end question Yep, posi (12 bolt), clean that thing up!!! Use a couple of cans of brake cleaner in there to clean it up, once it is clean (and dry, that's why you use brake cleaner, as it evaporates with no residue). Buy Royal Purple or the like (Synthetic) in gear lube and add the GM posi addative (local GM dealer will have it). As for the ratio, there are two numbers stamped into the ring gear (big gear) it'll look like this: 56:98 (example only) divide the big number by the little and you'll get 4.11 or 3.73, etc etc as in 4.11 posi 3.73 posi. BTW was it a L6 motor? I have had several inline six trucks and they all had 4:11 posi in them. Last edited by 70rs/ss; 08-28-2007 at 01:56 PM.