rear gears.... - NJFBOA - Home of New Jersey's Camaros and Firebirds

sweetbmxrider · 03-20-2009, 05:32 PM

alright i'm confused. 95 z28 a4. has the RPO code for 3.23's, GU5 if i'm not mistaking. shifter goes P R N [D] D 2. i jacked my rear up, marked my driveshaft, spun the wheel one rotation and came up with 2.73's. i feel gypped. so would this make my rear a 2 series? if so that blows

camaroAL · 03-20-2009, 05:34 PM

pop the cover and read the ring gear or count the teeth on both pinion and ring. dont go by revolutions.

sweetbmxrider · 03-20-2009, 05:43 PM

yeah i guess thats the definite answer. thanks.

WildBillyT · 03-20-2009, 05:52 PM

Quote:

Originally Posted by camaroAL

pop the cover and read the ring gear or count the teeth on both pinion and ring. dont go by revolutions.

Absolutely. GM ring gears may also have the tooth number stamped into them. I know on some older cars they do.

sweetbmxrider · 03-20-2009, 06:08 PM

the gm 3.73's i have now are stamped. how can i distinguish from series 2 and 3 gears?

WildBillyT · 03-20-2009, 06:11 PM

Quote:

Originally Posted by sweetbmxrider

the gm 3.73's i have now are stamped. how can i distinguish from series 2 and 3 gears?

What does it say on them?

Axle Ratio Tooth Combination
2.56:1 41,16
2.73:1 41,15
3.07:1 43,14
3.08:1 40,13
3.08:1 37,12
3.31:1 43,13
3.36:1 37,11
3.42:1 41,12
3.55:1 39,11
3.73:1 41,11
4.10:1 41,10
4.11:1 37,9

sweetbmxrider · 03-20-2009, 08:16 PM

thanks for the #'s bill. the ones i have out in my room are 41,11 - 3.73's. i will pop the cover and check what is in the rear now though.

LTb1ow · 03-21-2009, 09:46 AM

2.73s FTL. The ones I gave you are def 3.73s...

sweetbmxrider · 03-21-2009, 12:34 PM

yeah i know that. i'm just pissed from what i could tell i'm rockin 2.73's and i don't think those gears will fit.

NJ346 · 03-21-2009, 02:56 PM

Adam, if you look at the bottom of the carrier there should be a number 2 or 3 stamped followed by a bunch of other numbers that are smaller. This will tell u if it's a 2 or 3 series rear.

Featherburner · 03-21-2009, 03:03 PM

Quote:

Originally Posted by sweetbmxrider

yeah i know that. i'm just pissed from what i could tell i'm rockin 2.73's and i don't think those gears will fit.

You can make them work. http://www.riversidegear.com/categor...oduct-311.html
I've never used this and I don't know the "feeling" on these but it is what it is.

sweetbmxrider · 03-21-2009, 03:37 PM

thanks guys

BarneyMobile · 03-21-2009, 03:45 PM

I remember reading some where that if your shifter didnt have manual 1 selection on the shifter then you have 2.73's. The 3.23 geared cars were able to move the gear selector down into manual 1. My old 95 Z had a 1st gear selection on the shifter and had stock 3.23's

sweetbmxrider · 03-21-2009, 03:54 PM

yeah that is what some of the guys were telling me but i also have the rpo code for 3.23's. freakin weird.

Tru2Chevy · 03-21-2009, 08:23 PM

The RPO sheet might not be original to the car...

- Justin

sweetbmxrider · 03-21-2009, 08:45 PM

its a sticker in the glove box but i guess its possible. one day i'll take off the cover and verify everything.

Tru2Chevy · 03-21-2009, 09:11 PM

Quote:

Originally Posted by sweetbmxrider

its a sticker in the glove box but i guess its possible. one day i'll take off the cover and verify everything.

Yea.....in 3rd gens they are inside the lid of the center console, and since the center console lids are broken / cracked easily, it's not uncommon to see un-original (or non at all) RPO sheets in a 3rdgen.

- Justin

Jersyboyy · 03-30-2009, 01:56 AM

Feather burner got to the spacer thing before I could.

Iv read ALOT about them before I got a 4th gen 3 series rear.
Alot of guys talk trash about them but are all in theory they never actually run them just he said she said type of stuff.
Guys who have used them its like 1 out of 8 ever had a problem and its usually because they wernt set up right.

I would say if you are stuck with the 2:73's and have the 3:73s already...grab the spacer and have it installed by a real pro and just start saving for a real rear because like all 10 bolts it will break one day when your beating on it and that spacer may or may not take away some strength.

Some guys waste 500 bucks on a new diff thinking oh its a Eaton posi and now I can use my 373's....money well wasted itll break too.

WildBillyT · 03-30-2009, 08:27 AM

Quote:

Originally Posted by Jersyboyy

Feather burner got to the spacer thing before I could.

Iv read ALOT about them before I got a 4th gen 3 series rear.
Alot of guys talk trash about them but are all in theory they never actually run them just he said she said type of stuff.
Guys who have used them its like 1 out of 8 ever had a problem and its usually because they wernt set up right.

I would say if you are stuck with the 2:73's and have the 3:73s already...grab the spacer and have it installed by a real pro and just start saving for a real rear because like all 10 bolts it will break one day when your beating on it and that spacer may or may not take away some strength.

Some guys waste 500 bucks on a new diff thinking oh its a Eaton posi and now I can use my 373's....money well wasted itll break too.

A real pro will probably tell you to buy the right gears. And the spacer is just like the way wheel spacers work as far as putting stress on threads, etc.

sweetbmxrider · 03-30-2009, 09:10 AM

well i am looking at a roller that has 3.73's already so i may just sell these. i still want to know what i have in my car for future reference.