Author Topic: 12 bolt swap.  (Read 42683 times)

Offline SUX2BU99

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Re: 12 bolt swap.
« Reply #30 on: August 04, 2008, 06:49:07 PM »
Update: got the darn thing out! Man, those u-bolt nuts were TIGHT! And my impact gun is such a wimp. Took a while turning them 1/3 turn at time with the breaker bar or ratchet to get them loose.

I had the floor jack underneath ready to catch the diff when it came away from the leafs but that didn't happen as gracefully as I hoped. The diff was stuck to the leafs so I had to use a crowbar and a hammer to get them apart but when the last side came apart, if fell onto the floor jack, then fell forward and flipped over on the floor. Took a chunk of concrete out of my floor too! Oh well, it's out now anyway.

Is the diff supposed to be able to reasonbly balance itself on a floor jack? It sure doesn't seemt to want to. The snout keeps tipping it over. Because of this I'm not looking forward too much to getting the new diff positioned by myself.
85 Chevy Silverado C10 short, wide, yellow, 2wd. Lowered, 60-over 350 with Dart Iron Eagle heads and Comp Cams XE268 cam, TH350 w/ shift kit, 3.40 Gov-lok 12 bolt.

Offline VileZambonie

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Re: 12 bolt swap.
« Reply #31 on: August 04, 2008, 08:49:06 PM »
It'll go right up in there. Get one side into position on the pin and use another jack or stand to keep it in place then jack it up more to get the other side in.
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74 GMC, 75 K5, 84 GMC, 85 K20, 86 k20, 79 K10

Offline SUX2BU99

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Re: 12 bolt swap.
« Reply #32 on: August 05, 2008, 02:59:19 PM »
Good plan. I can manage that. I have a tube of Permatex thread sealant that I've been using on the brake hardware to prevent frozen fittings later on. Can I use this too on the u-bolts and shock bolts?
85 Chevy Silverado C10 short, wide, yellow, 2wd. Lowered, 60-over 350 with Dart Iron Eagle heads and Comp Cams XE268 cam, TH350 w/ shift kit, 3.40 Gov-lok 12 bolt.

Offline VileZambonie

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Re: 12 bolt swap.
« Reply #33 on: August 05, 2008, 03:16:22 PM »
Thread Sealant? No Don't put anything on them
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                         /  _ _ _\_
              ⌠ŻŻŻŻŻ'   [☼===☼]
              `()_);-;()_)--o--)_)

74 GMC, 75 K5, 84 GMC, 85 K20, 86 k20, 79 K10

Offline SUX2BU99

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Re: 12 bolt swap.
« Reply #34 on: August 05, 2008, 03:21:22 PM »
Cool. I thought I read something on the tube about not using on nuts that are critical to be torqued. The 'sealant' I think is more of a lube to prevent corrosion. Kinda like an anti-thread lock.

I did a search on here as I'm sure it was discussed before but I couldn't really find the answer I was looking for: what's the oil capacity of a 12 bolt? I have the number of 1.8L floating around in my head. Almost 2 bottles, but not quite. I'll be filling the new diff outside the truck with the snout pointing down (since it's easier that way), so I won't be filling it in the truck up to the point where it's level with the drain plug (the suggested method I found in another thread).
85 Chevy Silverado C10 short, wide, yellow, 2wd. Lowered, 60-over 350 with Dart Iron Eagle heads and Comp Cams XE268 cam, TH350 w/ shift kit, 3.40 Gov-lok 12 bolt.

Offline Captkaos

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Re: 12 bolt swap.
« Reply #35 on: August 05, 2008, 04:40:15 PM »
It should be 2.45 quarts.

Offline SUX2BU99

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Re: 12 bolt swap.
« Reply #36 on: August 05, 2008, 04:44:00 PM »
Ohhhh, well I'm glad I asked then. That's more like 2.5 bottles. Thanks!
85 Chevy Silverado C10 short, wide, yellow, 2wd. Lowered, 60-over 350 with Dart Iron Eagle heads and Comp Cams XE268 cam, TH350 w/ shift kit, 3.40 Gov-lok 12 bolt.

Offline SUX2BU99

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Re: 12 bolt swap.
« Reply #37 on: August 08, 2008, 01:04:39 PM »
Chris, not trying to 2nd guess you but is that quantity for a 12 bolt? I looked it up on the autozone site and they say 1 3/4 quarts, which is at the 1.8L (1 L = 1 quart) number I had in my head. I know when I had my oil changed in May, I bought 2 bottles and told the mechanic it takes 1.8L. That number came from somewhere, but I just can't remember.
85 Chevy Silverado C10 short, wide, yellow, 2wd. Lowered, 60-over 350 with Dart Iron Eagle heads and Comp Cams XE268 cam, TH350 w/ shift kit, 3.40 Gov-lok 12 bolt.

Offline ccz145a

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Re: 12 bolt swap.
« Reply #38 on: August 10, 2008, 03:44:55 PM »
Why not just fill it when you get it in the truck the normal way?
1975 C10 Silverado LWB, 454CID, TH400, 10bolt 3.42
11MPG Downhill w/tailwind (but there ain't no hills here)

Offline Captkaos

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Re: 12 bolt swap.
« Reply #39 on: August 11, 2008, 10:42:53 AM »
Your right, I think it is almost 2 quarts from empty.

Offline SUX2BU99

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Re: 12 bolt swap.
« Reply #40 on: August 11, 2008, 11:21:23 AM »
Since I had both diffs sitting in my garage wtih the snouts hanging down, it was easy for me to swap covers and fill the new diff with oil, of which I did. I put in 2 quarts of Castrol 80W-90 Hypoy C oil along with a bottle of GM friction modifier for posi diffs.
85 Chevy Silverado C10 short, wide, yellow, 2wd. Lowered, 60-over 350 with Dart Iron Eagle heads and Comp Cams XE268 cam, TH350 w/ shift kit, 3.40 Gov-lok 12 bolt.

Offline SUX2BU99

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Re: 12 bolt swap.
« Reply #41 on: August 12, 2008, 05:20:48 PM »
Does anybody have the torque values for the following:

- u-bolt nuts
- u-joint nuts
- shock bolts
- diff cover bolts

Thanks!
85 Chevy Silverado C10 short, wide, yellow, 2wd. Lowered, 60-over 350 with Dart Iron Eagle heads and Comp Cams XE268 cam, TH350 w/ shift kit, 3.40 Gov-lok 12 bolt.

Offline ccz145a

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Re: 12 bolt swap.
« Reply #42 on: August 12, 2008, 07:41:46 PM »
These values are best read from a good book.  I am sure no one here would deliberately steer you wrong, however it is a good habit to get into to verify something as important and easy to look up as torque values.

1975 C10 Silverado LWB, 454CID, TH400, 10bolt 3.42
11MPG Downhill w/tailwind (but there ain't no hills here)

Offline eventhorizon66

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Re: 12 bolt swap.
« Reply #43 on: August 12, 2008, 08:58:16 PM »
I refer to this page alot, for stuff like that.  Can't vouch for the accuracy of the info though.  Check the bottom of the page.
'85 C10 SWB 350 700R4 TKO600

Offline SUX2BU99

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Re: 12 bolt swap.
« Reply #44 on: August 13, 2008, 11:30:15 AM »
^ Wow, cool site! Definitely one to bookmark and go through.  Thanks for that, and yes I should just buy at least a Haynes manual for stuff like this.

CCZ, when you swapped your axle, what was your method of getting the shocks back on to their mount? They have to be compressed I know. I was under there last night cleaning the area up in prep for the new axle which should be going in tonight I hope  ;D and I tried compressing the shock myself but it didn't want to seem to budge. Should I use the floor jack to compress it enough to get onto the shock mount?
85 Chevy Silverado C10 short, wide, yellow, 2wd. Lowered, 60-over 350 with Dart Iron Eagle heads and Comp Cams XE268 cam, TH350 w/ shift kit, 3.40 Gov-lok 12 bolt.