Assembling the posi
Thread Starter
Racer
Joined: Jun 2001
Posts: 440
Likes: 0
From: Sanford Florida
Assembling the posi
How difficult of a job is it to actually put the posi internals into the posi case. Buying the posi internals (clutches, spiders...) and installing them into the cage that they go into myself is cheaper, but I want to know if anyone has done it. Also, what should I watch out for if I want to install new gears on my rear end? It is in an 80. Thanks, Charlie
[Modified by chuckb01, 3:36 PM 4/2/2002]
[Modified by chuckb01, 3:36 PM 4/2/2002]
Thread Starter
Racer
Joined: Jun 2001
Posts: 440
Likes: 0
From: Sanford Florida
Re: Assembling the posi (gtr1999)
Right now, I have the entire rear end apart, including the rear end itself being out. I have taken the cover off, and the axles will come out when i want. Right now, before I start tearing into it, i want to justify myself spending the money on a new 4.55 rear. That is what I really want, but the $450 may not be that easy to come by. For sure I will get the 3.73 gears, and no new carrier, but I think I may just say "f" it and buy the new carrier and posi for the 4.55 gears. I will make up my mind in a few days, and will post again or refresh this post for help. Thanks :)
Pro
Joined: Jun 2001
Posts: 683
Likes: 0
From: Calgary
Re: Assembling the posi (chuckb01)
If anyone is interested, I have a pamphlet from Toms differentials on how to set up your posi. I could fax it to someone who could scan it onto the forum. Actually, I have a scanner, just not the know-how to scan it onto the forum.
Pro
Joined: Jun 2001
Posts: 683
Likes: 0
From: Calgary
Re: Assembling the posi (gtr1999)
The way I set mine up:
Put your posi unit in a vice leaving the large opening accessable. install original shims, new clutch packs, cross shaft and gears. Put your side yolks into the posi case gears and try to twist one yolk against the other.
Keep shimming the posi clutches equally, until you can barely twist the side yolks by hand. Also, if you look closely at the clutches, you will see 2 different patterns (one is cut deeper)on them. Alternate the patterns so they slip (mate) one against the other (facing each other).
While you are at it, you should drill your diff housing for a drain (just forward of the pinion gear), chamfer all machined portions of the housing, set up your bearing caps for 0.001" rock (on the posi bearing races), and use grade 8 allen bolts to hold your caps in place. Also polish all the openings in the posi case.
Put your posi unit in a vice leaving the large opening accessable. install original shims, new clutch packs, cross shaft and gears. Put your side yolks into the posi case gears and try to twist one yolk against the other.
Keep shimming the posi clutches equally, until you can barely twist the side yolks by hand. Also, if you look closely at the clutches, you will see 2 different patterns (one is cut deeper)on them. Alternate the patterns so they slip (mate) one against the other (facing each other).
While you are at it, you should drill your diff housing for a drain (just forward of the pinion gear), chamfer all machined portions of the housing, set up your bearing caps for 0.001" rock (on the posi bearing races), and use grade 8 allen bolts to hold your caps in place. Also polish all the openings in the posi case.
Melting Slicks
Joined: Dec 2000
Posts: 3,407
Likes: 2
From: Carmichael CA
Re: Assembling the posi (74vetteman)
Hey vetteman,
Any chance you can submit your post to the tech tips section for C3s? I'm not doing the rear end right now, but someday I might and your post sounds very helpful. I'd hate to be searching the archives for it in two years.
Any chance you can submit your post to the tech tips section for C3s? I'm not doing the rear end right now, but someday I might and your post sounds very helpful. I'd hate to be searching the archives for it in two years.
