Cascade Crew

Magman

How do I determine if a 9-bolt rear is Posi or not? This is unfamiliar territory for me. I can pop the cover tomorrow and post a pic of what it looks like inside, but I'm unsure of what I should be looking for? Thanks!

Twilightoptics · Posted: Wed Nov 12, 2008 9:02 pm Post subject:

Best way it to just turn one axle and see which way the other axle turns.

Same direction = working posi

Opposite directions = non posi/worn out posi

chevymad · Posted: Wed Nov 12, 2008 10:10 pm Post subject:

What Paul says on the 9bolt. Now if it was a 10 bolt you'd have to worry about the Zexel/torsens which act like a non posi.

Magman · Posted: Thu Nov 13, 2008 5:44 am Post subject:

OK, thanks. I'll give that a shot and see what happens.

Xophertony · Posted: Thu Nov 13, 2008 12:17 pm Post subject:

lucky for you almost all of the 9 bolt rears are "performance" optioned with at least an ok gear ratio, and posi. most are 3.27:1 or 3.40(ish):1.

Very Happy

australia is cool.

Twilightoptics · Posted: Thu Nov 13, 2008 5:33 pm Post subject:

Hmm never seen anything but 3.27 and 3.70s

Xophertony · Posted: Thu Nov 13, 2008 6:02 pm Post subject:

3.70.. I knew it was something big. my mistake on the 3.40ish.

rjmcgee · The Hammer Joined: 08 Jan 2004 Posts: 2328

Magman · Posted: Thu Nov 13, 2008 9:03 pm Post subject:

Yeah, that's what everyone says. The 9-bolt is superior. I had no luck turning one side of this one tonight though. The right brake seems to be locked up. I'll have to take the brakes off to check it out. The left side turns freely while the right is locked up by the brake.

I also read the 9-bolts have different axles, 26 spline before 88 and 28 splines after. This rear wasn't stock though, it has "87 Camaro" written on it in yellow marker. Typical marker used in wrecking yards Sad

83Z28BlackBetty · Posted: Fri Nov 14, 2008 12:31 am Post subject:

if you can turn one wheel freely while the other is locked up, then its not a posi, at least not a working one.

What kind of brakes? are they the aluminum PBR's?

~JAKE

Magman · Posted: Fri Nov 14, 2008 6:01 am Post subject:

No, non-PBR. This things a paper weight... 2.77 gears, non PBR, unitrack, it doesn't have anything going for it!

Twilightoptics · Posted: Fri Nov 14, 2008 5:36 pm Post subject:

redlava · Posted: Sun Nov 16, 2008 11:45 am Post subject:

pull it apart and take a look at the posi cones to see if they are completely worn out or if it possible to shim

Magman · Posted: Sun Nov 16, 2008 2:06 pm Post subject:

Yeah, I was thinking of pulling it apart to see what it's made of. Plan to keep the shims as spares for the 3.45 9-bolt I have waiting to be rebuilt. More and more projects just keep piling up...