Squarebody Differentials.

[nxtlevl]

Good info to have....That's what I love about this site....

 

[89Suburban]

Is 80w90 oil ok for my rears? I feel like doing a few write ups tonight.

 

[89Suburban]

Also, can I just use sealer instead of a gasket for the covers?

 

[skysurfer]

Also, can I just use sealer instead of a gasket for the covers?

You probably could, but if you torque down the cover too soon you'll squish out most of the sealant and have a potential leak. You have a parts store nearby and the gasket is cheap so why not use both?

 

[89Suburban]

I went to my local parts guy and he said he doesn't even list gaskets for it. But I do see them on RockAuto's site. My guy said I will be fine just using the sealant if I let it skin up before I put the cover on. If I had planned ahead I would have ordered the gaskets from RockAuto, but this is was a spontanious decision this morning and I have time this weekend to tackle it and do some write ups. If I have a leak later I can order the gaskets and redo it, no big deal. I also asked him to order in a trans filter kit and rear u-joints and will be doing write ups on them in the next week or 2.

I can't find any info on the oil question I asked about here so I just got some 80w909 oil for the changes. It says on the bottle it should work for limitied slip rears.

 

[HotRodPC]

Sealer is fine. No big pressure there. But as Sky says, let is set up just a bit before you tighten the bolts. 80-90w GL4 or GL5 should be fine. Love the smell of that **** !!! Don't get it on your clothes. It seems the stuff don't like to wash out for some reason.

 

[89Suburban]

Sealer is fine. No big pressure there. But as Sky says, let is set up just a bit before you tighten the bolts. 80-90w GL4 or GL5 should be fine. Love the smell of that **** !!! Don't get it on your clothes. It seems the stuff don't like to wash out for some reason.

Anything I should look for while it's apart homie?

 

[89Suburban]

Ok, brought all this **** to work with me so I can do the gear oil changes later today.

 

[HotRodPC]

Ok, brought all this **** to work with me so I can do the gear oil changes later today.

hahaha, did you get enough oil for the diff??? How many times you gonna change it???

 

[Irishman999]

Anything I should look for while it's apart homie?

Yea chunks of gear haha! you dont have to have the gasket, I did the same ****.... I thought of everything except a gasket and improvised with the black RTV silicone.

One thing I did not notice in your goodie box is the tube of limited slip additive, I think its voodoo but use it anyways.

 

[HotRodPC]

Yea chunks of gear haha! you dont have to have the gasket, I did the same ****.... I thought of everything except a gasket and improvised with the black RTV silicone.

One thing I did not notice in your good box is the tube of limited slip additive, I think its voodoo but use it anyways.

I'll say this, I am a hater of just about every additive possible. But when it comes to that additive for diffs, if the book or dealer calls for it, USE IT !!! It pretty critical in those rear ends that require it for some reason. I am thinking he is OK without though. I am not even sure the G80 locking diff requires an additive. My 2003 Avalanche with G80 didin't but it required the dealer gear oil at $35 a quart and it took a quart and half, so 2 quarts was $70 and I still have half a quart.

 

[DoubleDingo]

My '81 C20 has a 14 bolt SF. Decided to count the bolts while I was crawling around under the truck earlier this week.

 

[HotRodPC]

My '81 C20 has a 14 bolt SF. Decided to count the bolts while I was crawling around under the truck earlier this week.

yeah a C20 always has 14 bolts. Just a matter of does it have the big hubs that stick out of the wheels for floating axles, or is it smooth with the wheel? If the hubs stick out its Full Float, if it's smooth then it's Semi Float. Also the SF is more of a roundish rear cover where the Full Float is bigger and like and off angled sizes octagonish looking.

 

[DoubleDingo]

yeah a C20 always has 14 bolts. Just a matter of does it have the big hubs that stick out of the wheels for floating axles, or is it smooth with the wheel? If the hubs stick out its Full Float, if it's smooth then it's Semi Float. Also the SF is more of a roundish rear cover where the Full Float is bigger and like and off angled sizes octagonish looking.

I mentioned that because the list at the beginning of the thread showed 82 and newer as having the SF. I do have two older FF's, a '65 corporate and a '69 Dana 44 or 60, not sure on the '69.

 

[bucket]

I thought the SF started in '81 too.