faulball67

iTrader: (2)

My RPO codes for my 86 IROC tell me

1) GU5 - 3.23 axle ratio
2) G80 - limited slip rear

My question is do I have 7.5 or 7.65 rear? Or does it even matter? Also, do I have a series 2 or 3 carrier? How can I tell? I'm new to playing with rear end gears and what not so I'm not sure what all to look for.

84z28350

It doesnt make a difference if its 7.5/7.65, gears will interchange.


If its 3.23 gears its a 3 series.

3.08 down = 2 series
3.23 up = 3 series

faulball67

iTrader: (2)

thanks. What about the diff cover? Same thing?


btw ... like your sig. It's like a take off of the POW/MIA gone but not forgotten logos

Apeiron

There's no difference at all between the 7.5" and 7.625" rears, except for the difference in size of the actual gears themselves, which is negligible.

84z28350

^^^^



Their the same **** different pile!

Covers are the same on both

irocbarry

[QUOTE=84z28350]
Their the same **** different pile!

QUOTE]

thats some of the funniest crap ive ever heard on here

84z28350

Im glad i amuse you...

AlkyIROC

I think technically, in 1986, it became a 7-5/8" ring gear but other than the slight increase in size, it's still called a 7-1/2" 10 bolt.

Sonix

iTrader: (1)

I think that's not always true. I heard my 3.23 gear set uses a 2 series posi.

Apeiron

The difference in the different "series" is the location of the ring gear mounting surface away from the pinion centerline in order to fit larger pinions with more teeth. Some gear sets use thicker ring gears to fit the "wrong" carrier for their ratio.

84z28350

They do make crown/pinion sets to fit opposite series carriers.

faulball67

iTrader: (2)

from what I've been reading and what is noted on summit racing, all stock 7.5 10 bolts with 3.23 gears use a series 3 carrier.

You can get the 3.23 gears for the series 2 carrier aftermarket but I don't think they came stock that way.

Sonix

iTrader: (1)

I beg to differ on that one. It might be aftermarket, but I highly doubt it.

faulball67

iTrader: (2)

Your sure it's a 7.5? It is an 82 right? That could make a difference.

I was looking on summit for a ring and pinion set and they only seem to have them for 27 and 28 spline but not stock 26 spline. Does this mean I will HAVE to change out the axles? Or is there some where else I need to look?

84z28350

ummmmm, are any of gm's rears a 27 spline?....


27 spline is dodge is it not?

Thats axles anyway...

The pinion might be 27 spline though....

Sonix

iTrader: (1)

27 spline pinion count, that's normal. 26/28 spline axles don't matter to the ring and pinion.

yep, my 82 has a 7.5", I used a summit girdle cover, and it fit, and I used a zytanium cross pin, and all other parts meant for a 7.5" rear so...

faulball67

iTrader: (2)

OOPS I guess I should have asked before I opened my mouth. Pinion spline count doesn't have anything to do with axle spline count does it?

Oh whatanass I am
----------
when I pull my diff how will I be able to tell what series carrier it is? Also, how can I tell if the gears have been changed to something else.

84z28350

No it doesnt...


You just had me a bit confused there when you started talking splines, i didnt know if you were talking pinion or axle (you could have been replacing spiders if it was a non posi)

faulball67

iTrader: (2)

sorry. this is my first work on a rear axle. I've done most other things you can think of when it comes to performance but never new rear gears or diffs. guess that's what happens when you learn how to build engines from your old man and have to learn the rest for yourself.

Sonix

iTrader: (1)

I rebuilt my 10 bolt a few months ago, try searching under my name and "10 bolt rebuild" and "carrier removal". I had a hell of a time, but there's some good info there.

sofakingdom told me I had a 2 series, that's as much info as I have. Basically, if where your ring gear bolts are, if that surface is flat, it's a 2 series, and if it's more conical, it's a 3 series. I think anethsis posted a side by side pic a while ago...(memory slipping..)

the axle spline count must match your posi carrier spline count. ring and pinion gears must match the carrier, or be "thick gears" or have a spacer.

count the teeth on your pinion, and the teeth on your ring gear. Ring gear divided by pinion is your ratio. So if your ring gear has 41 teeth, and pinion has 12, then it's 3.42.