[Darth Menace]

Hey first off sorry about my constant thread starting with incessant questions

Anyways yesterday I drained the gear fluid so I can get the cover all cleaned up while I wait for the gasket to come. I was wondering if there is a bolt sequence to do it up and how much to torque it down. I'm a real keener on over-tightening things and it sucks.

Also, the manual says 80W or 90W. Would 80W90 suffice?

Also, sorry if this is a dumb question but does this need slip lock additive?

[propuckstopper]

I use 75W-110 in the Amsoil Severe Gear variety. The SAE spec changed some years ago, hence my decision to go to the 110, which is closer to the old 90 spec anyway. Amsoil claims that no additive is needed, but I put in half the recommended dose (about 2 ounces) of additive just for kicks.

I use a gasket on the cover of both my cars, and I use a small amount of Permatex Aviation Sealer on both sides of the gaskets. Neither leak a drop.

Rear end is quiet as heck and no chattering. Works for me...

[Darth Menace]

dont know/don't know. It is a 69 custom s. It was originally a 6 cyl, but I am not sure about the rear end

[propuckstopper]

Originally Posted by Darth Menace

dont know/don't know. It is a 69 custom s. It was originally a 6 cyl, but I am not sure about the rear end

With the cover off, you should be able to see whether the unit is of the open variety or a posi. Just Google "Auburn Posi" to see what I am talking about, then compare it to what you have behind your cover. The posi unit looks more extensive, with springs and a cone-clutch setup. I have a great picture in my service manual beside me, but I am not near a scanner. No posi=no additive required.

My best guess is that your rear end is open (that sounds weird!!!), based on the Custom S and the six cylinder mill.

I go about 22 foot pounds on the cover bolts.

EDIT: Here is a picture of a posi unit.

[rexs73gto]

I to use 5w110 syn. gear oil in all my rear ends & manual trans. It makes them shift smoother & if you ever drive them in weather thats a bit colder outside you'll find that they will shift much easier to shift when it's cold. You don't have to wait for it to warm up to shift easy. With the syn. fluid I always use the posi additive if it's a posi. But if it isn't you don't have to use it. To find out when it's off you will be able to see the extra parts for the posi but if it's up in the air all you need to do is spin the wheels & if both wheels go the same direction then it's a posi if one turns & the other either goes the opposite direction or does turn at all then it's an open rear end. As the the last poster said though, being it was a custom s & a 6 cyl, weel most likely not a posi

[Darth Menace]

Originally Posted by propuckstopper

With the cover off, you should be able to see whether the unit is of the open variety or a posi. Just Google "Auburn Posi" to see what I am talking about, then compare it to what you have behind your cover. The posi unit looks more extensive, with springs and a cone-clutch setup. I have a great picture in my service manual beside me, but I am not near a scanner. No posi=no additive required.

My best guess is that your rear end is open (that sounds weird!!!), based on the Custom S and the six cylinder mill.

I go about 22 foot pounds on the cover bolts.

EDIT: Here is a picture of a posi unit.

Thanks for the info. Ya mine is just one gear (not near as clean as that). Looks like i should replace the rear end some day....i wasnt keen on the one wheel peels in the mutang

[propuckstopper]

Originally Posted by Darth Menace

Thanks for the info. Ya mine is just one gear (not near as clean as that). Looks like i should replace the rear end some day....i wasnt keen on the one wheel peels in the mutang

Keep in mind: You can buy an aftermarket Eaton, Auburn, or Yukon Posi unit and install it in your current housing. In fact, I have a brand new Eaton posi, 3.55:1 ring and pinion, and complete bearing kit on my shelf right now. When I find a nice 1965 GTO rear end housing, I am going to build it up with the new parts.

Any good trans/diff shop in your area will be able to help you out with this.

Have a great Christmas!

[Darth Menace]

Originally Posted by propuckstopper

Keep in mind: You can buy an aftermarket Eaton, Auburn, or Yukon Posi unit and install it in your current housing. In fact, I have a brand new Eaton posi, 3.55:1 ring and pinion, and complete bearing kit on my shelf right now. When I find a nice 1965 GTO rear end housing, I am going to build it up with the new parts.

Any good trans/diff shop in your area will be able to help you out with this.

Have a great Christmas!

Ya looks good. Maybe in a couple years I will get to that. I'm not going to lie...getting it to a nice looking driver will take enough energy as it is Can't justify $500'ish right now

[Darth Menace]

Originally Posted by propuckstopper

I use 75W-110 in the Amsoil Severe Gear variety. The SAE spec changed some years ago, hence my decision to go to the 110, which is closer to the old 90 spec anyway. Amsoil claims that no additive is needed, but I put in half the recommended dose (about 2 ounces) of additive just for kicks.

I use a gasket on the cover of both my cars, and I use a small amount of Permatex Aviation Sealer on both sides of the gaskets. Neither leak a drop.

Rear end is quiet as heck and no chattering. Works for me...

Nice, I use the Amsoil 75-110 in my Viper and Charger, so I was wondering why the lighter weight in the Pontiac. I will do the 75-110 if it works for you guys as well.

[Darth Menace]

I've scraped at the gasket a tonne with a razor blade, used wd40 and laquor thinner. Any other sure-fire ways of getting this old gasket off? Would a dremel or hand sander be okay as long as it's not coarse sandpaper?

[rexs73gto]

No don't use anything mechanical as it will send the extra grinding material into the rear end & cause junk in the rear end. Just keep scraping.

[Darth Menace]

Originally Posted by rexs73gto

No don't use anything mechanical as it will send the extra grinding material into the rear end & cause junk in the rear end. Just keep scraping.

okay, I think I will try some more liquids. Is heating it with a heat gun okay too? It is pretty cold here in Alberta

[rexs73gto]

Yes heat is a good idea, as you may try a regular type of gasket scraper rather then just a razor blade scraper. Heat will soften up what ever is on the rear end & cover so it will scrape off easier.

[gtohurstjudge]

In my shop we only use silicone to seal the rear end cover. In my experience
if you use a gasket there is a high probability of a leak.

[rexs73gto]

I always use both gasket & sealer when I put on a rear end cover & for me that works the best.

[Darth Menace]

Originally Posted by gtohurstjudge

In my shop we only use silicone to seal the rear end cover. In my experience
if you use a gasket there is a high probability of a leak.

Ya I haven't done a tonne of car work like you guys, but there are a few I have done I have found out that there was no gasket from factory. This gasket is part of the diff. I wouldn't be surprised if it's the original one

[rexs73gto]

The factory has always used a gasket on the rear diff. The first year GM started to usedGMS only for the rear diff was the 96 impala ss, they used the GMS on the rear diff as it was done now by the automated system on the line. But All Pontiacs had a gasket intalled on all rear diffs. up to & included the 81 F-bodies.

[propuckstopper]

Originally Posted by rexs73gto

The factory has always used a gasket on the rear diff. The first year GM started to usedGMS only for the rear diff was the 96 impala ss, they used the GMS on the rear diff as it was done now by the automated system on the line. But All Pontiacs had a gasket intalled on all rear diffs. up to & included the 81 F-bodies.

I like rex's reply. Many folks use silicone to seal rear diffs and don't use a gasket, and it mostly produces a successful seal. I just don't like the "oozing" that goes on, whether it be outside the differential or within, which you can't see. That's why I don't like silicone.

I know some guys try to go lighter on the silicone, but I just find the stuff makes a damn mess. For me, at least, it is not "controllable" enough, although I realize I am not great at applying silicone. After many years, I finally got pretty good at doing countertops and shower surrounds and can make a pretty nice looking bead, but the "stress of the mess" drives me nuts. It's a personal thing.

If you want to keep it clean, find yourself some nice Permatex Aviation Sealer. It is available (in Canada at least) at places like Canadian Tire and NAPA. It comes with a nice little applicator brush, and is super easy to work with.

On a nice clean rear differential cover, I brush a decent, but not excessive amount of Aviation Sealer around the entire circumference and the bolt holes. I let it "flash-off" for about 10 minutes, then stick the gasket down on the Aviation Sealer. I then brush the Aviation Sealer on the side of the gasket that will contact the rear end housing, and repeat the "flash-off" process before bolting it up.

Never a leak in 28 years, and wonderful to take apart when you need to change you differential fluid. You won't need a jackhammer to get it clean the next time around.

Just one guy's opinion...

[Darth Menace]

Originally Posted by propuckstopper

I like rex's reply. Many folks use silicone to seal rear diffs and don't use a gasket, and it mostly produces a successful seal. I just don't like the "oozing" that goes on, whether it be outside the differential or within, which you can't see. That's why I don't like silicone.

I know some guys try to go lighter on the silicone, but I just find the stuff makes a damn mess. For me, at least, it is not "controllable" enough, although I realize I am not great at applying silicone. After many years, I finally got pretty good at doing countertops and shower surrounds and can make a pretty nice looking bead, but the "stress of the mess" drives me nuts. It's a personal thing.

If you want to keep it clean, find yourself some nice Permatex Aviation Sealer. It is available (in Canada at least) at places like Canadian Tire and NAPA. It comes with a nice little applicator brush, and is super easy to work with.

On a nice clean rear differential cover, I brush a decent, but not excessive amount of Aviation Sealer around the entire circumference and the bolt holes. I let it "flash-off" for about 10 minutes, then stick the gasket down on the Aviation Sealer. I then brush the Aviation Sealer on the side of the gasket that will contact the rear end housing, and repeat the "flash-off" process before bolting it up.

Sounds nice, which one is it at Canadian Tire? http://www.canadiantire.ca/en/search...rue&q=permatex

[2cdavis3]

This is what I always use, never had a leak
http://www.canadiantire.ca/en/pdp/pe...-0383717p.html