Which posi is this? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

pritch · 04-30-2011, 09:12 PM

I decided to pop the cover off my diff today. I thought this truck had a posi, but I wanted to make sure:

Man, when I pulled the cover off, I thought someone had filled it up with tar! It was some mean looking goop in there. Should I try to rinse it out with something? I have heard it's best to use special posi oil-does anyone know what that is?

Thanks

usmcchevy · 04-30-2011, 10:42 PM

Eaton clutch type posi. Its what came factory in these trucks. Spray/wipe it out with brake cleaner, fill with lube and the posi additive.

pritch · 05-01-2011, 11:59 AM

Quote:

Originally Posted by usmcchevy

Eaton clutch type posi. Its what came factory in these trucks. Spray/wipe it out with brake cleaner, fill with lube and the posi additive.

Serious? Brake cleaner? I would not have guessed that.

Thanks for the Eaton info, BTW.

prostreetC-10 · 05-01-2011, 04:12 PM

For what ever it's worth, if you ever wanted to be positive what your gear ratio is, it will be on the edge of the ring gear and the last numbers. Divide the little number into the big.

pritch · 05-01-2011, 08:29 PM

Yeah-I was going to do that very thing as soon as get it cleaned up a little. It was kind of a sideways step, pulling the cover off. I could have taken this truck for it's maiden trip around the block today if I hadn't. Now I need to get a gasket and some gear lube tomorrow when I get down to the big city. I think I'm gonna fill it with clean gear lube and put some miles on and then drain that and re-fill with the posi-lube and more new gear lube.

Thanks.

kelsfine69 · 05-01-2011, 08:53 PM

I would drive it for a couple months and change it again.

pritch · 05-03-2011, 09:05 PM

Quote:

Originally Posted by prostreetC-10

For what ever it's worth, if you ever wanted to be positive what your gear ratio is, it will be on the edge of the ring gear and the last numbers. Divide the little number into the big.

11:41=3.727272. I guess that must be 3.73's

dmack91 · 05-03-2011, 11:09 PM

Hmm, I didn't think Eaton's went that high. I thought 4.56 was as high as they went.

prostreetC-10 · 05-04-2011, 12:23 AM

Quote:

Originally Posted by pritch

11:41=3.727272. I guess that must be 3.73's

Exactly what mine was. Great gear with a 4 speed!

cdowns · 05-04-2011, 08:26 AM

a better choice on lube is synthetic. the good stuff like royal purple does not need and posi additives either

BIGKEV · 05-04-2011, 12:44 PM

Quote:

Originally Posted by pritch

Yeah-I was going to do that very thing as soon as get it cleaned up a little. It was kind of a sideways step, pulling the cover off. I could have taken this truck for it's maiden trip around the block today if I hadn't. Now I need to get a gasket and some gear lube tomorrow when I get down to the big city. I think I'm gonna fill it with clean gear lube and put some miles on and then drain that and re-fill with the posi-lube and more new gear lube.

Thanks.

Don't even bother with a gasket! Get some right stuff and be done with it.

pritch · 05-04-2011, 09:50 PM

Quote:

Originally Posted by BIGKEV

Don't even bother with a gasket! Get some right stuff and be done with it.

That's for round two. The old grease was so nasty I decided to fill it up with some plain old gear lube and run it for a few hundred miles then dump it again. I'll use a good sealer at that time. I just wanted it to be easier to clean up when that time comes. I did take it out for a little spin tonight, and it worked good, it locked right up when I broke the rears loose in some soft dirt.

Sillyoldman · 05-04-2011, 10:02 PM

Quote:

Originally Posted by BIGKEV

Don't even bother with a gasket! Get some right stuff and be done with it.

^X2 but make sure you wear gloves!

04-30-2011, 09:12 PM	#1
pritch Registered User Join Date: Mar 2004 Location: Hoytsville, Utah Posts: 3,365	Which posi is this? I decided to pop the cover off my diff today. I thought this truck had a posi, but I wanted to make sure: Man, when I pulled the cover off, I thought someone had filled it up with tar! It was some mean looking goop in there. Should I try to rinse it out with something? I have heard it's best to use special posi oil-does anyone know what that is? Thanks __________________ '68 Panel Project Boogie Chillin' '68 C-10 Ol' Green

04-30-2011, 10:42 PM	#2
usmcchevy Has more rust than truck... Join Date: Apr 2005 Location: Ivanhoe, MN Posts: 2,421	Re: Which posi is this? Eaton clutch type posi. Its what came factory in these trucks. Spray/wipe it out with brake cleaner, fill with lube and the posi additive. __________________ 1972 Custom/10 SWB, 4.8/4l80e Build thread LSx Swap FAQ index

05-01-2011, 04:12 PM	#4
prostreetC-10 My Carbon Footprint Join Date: Oct 2008 Location: Orygun Posts: 5,527	Re: Which posi is this? For what ever it's worth, if you ever wanted to be positive what your gear ratio is, it will be on the edge of the ring gear and the last numbers. Divide the little number into the big. __________________ A quick "pedalfest" *Still getting loose (carb test)* 496 Initial fire up video! Last edited by prostreetC-10; 05-01-2011 at 04:14 PM.

05-01-2011, 08:29 PM	#5
pritch Registered User Join Date: Mar 2004 Location: Hoytsville, Utah Posts: 3,365	Re: Which posi is this? Yeah-I was going to do that very thing as soon as get it cleaned up a little. It was kind of a sideways step, pulling the cover off. I could have taken this truck for it's maiden trip around the block today if I hadn't. Now I need to get a gasket and some gear lube tomorrow when I get down to the big city. I think I'm gonna fill it with clean gear lube and put some miles on and then drain that and re-fill with the posi-lube and more new gear lube. Thanks. __________________ '68 Panel Project Boogie Chillin' '68 C-10 Ol' Green

05-01-2011, 08:53 PM	#6
kelsfine69 18 Till I Die Join Date: Mar 2005 Location: Alberta, Canada Posts: 1,522	Re: Which posi is this? I would drive it for a couple months and change it again. __________________ 2011 GMC Acadia 1969 GMC BBC LS7 2007 GMC Crew Duramax 1987 Camaro Iroc 350 Tuned Port Injection 42000Km 1987 Chevrolet Silverado 350 TBI 1987 Chevrolet Silverado 350 TBI(yes 2) Take me drunk, I'm too home...

05-03-2011, 11:09 PM	#8
dmack91 Registered User Join Date: Jan 2011 Location: Redmond, OR Posts: 759	Re: Which posi is this? Hmm, I didn't think Eaton's went that high. I thought 4.56 was as high as they went. __________________ 68 Chev C20- son has it now 83 K20 - bought from son 70 C20 - in progress

05-04-2011, 08:26 AM	#10
cdowns Senior Member Join Date: Jan 2003 Location: daytonabeach Posts: 22,956	Re: Which posi is this? a better choice on lube is synthetic. the good stuff like royal purple does not need and posi additives either __________________ 71c-10 350/2004r/4:11 lowered3/4 longbed/dead by hurricane MEANING OF DEATH::::: SOMEBODY ELSE GETS YOUR STUFF DONT BELIEVE EVERYTHING YOU THINK TAKE MY ADVISE;I DON'T USE IT ANYWAY



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