Recently I posted that I checked the 9-bolt axle part numbers at the dealer, and they were the same from 85-89. So I thought since 85-89 10-bolts are 26 spline axles, I figured 9-bolts were 26 spline axles too. Well guess what I found out yesterday? 9-bolts are all 28 spline axles!! I pulled one out of a 88 today, and counted 28 splines. And since the part numbers are the same, all 9-bolts must be 28 spline axles too. Yet another reason why 9-bolt rear ends are stronger than 10-bolts.


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1991 Camaro Z28
5.7L 5-Speed (originally 305)
13.23 @ 107.62 MPH
Southern California
Member: SoCal 3rd Gen F-Bodies
Webmaster: SoCal F-Bodies
-=ICON Motorsports=-

 

Cool...now if we can only get the prices of our gears and posi down it would be a great rear to have... BTW anyone know where to get a set of series 2 gears for the 9 bolt that are around 3.45??

 

I have the opportunity to get a 9 bolt from a 1988 GTA 5.7L 350 hard top. I am curious whether this is a 3.27 ratio or worse 2.77. I have not been able to locate the RPO codes in the glove box, I guess I have to check the hatch area.

Is the 2.77 the same carrier as the 3.27?

If so I plan on installing the 3.70s.

I am probably going to spring for the Dana44 if this 9 bolt is a 2.77. My rear is holding me away from using the camaro at the track for some new times- becoming extremely impatient. 8)~

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Hybrid Black 5.7L 5 Speed
'95 Competition Yellow Corvette Coupe ZF6

 

That has been stated before. 28 splines on all of the 9 bolts. Plus, they have 4 pinion gears mating with 2 side gears (instead of 2 and 2), which makes them stronger.
It's almost done. They won't be as cheap as 10 bolt stuff, but the selection will be there (up to 4.11's).

There isn't any, but new series 3 carriers are on the way soon.

Nope. 2.77 is series 2 and 3.27+ is series 3.

Miles


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88 427 Camaro
12.18 @ 113mph 1.75 60ft
Currently installing 3.73's into my 9 bolt (YES,it is a 9 bolt & YES they are 3.73's, not 3.70. 4.11's to follow soon )
www.koolmeister.com

 

"stronger" yet the only people I know that have shelled gears were 9-bolt cars. hmmmm... Plus, when they go out you're screwed. it's cheaper to buy a whole used rear than a new set of gears....IF....you can find them since GM discontinued them. p.s. I have a 3.45 disc setup forsale $500

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Kyle Osterholt
Okarche, Oklahoma
ASE Master Certified
86 T/A 383 TPI
89 TTA #1002 T-top/Leather
89 TTA #1358 Hardtop/Leather
80 T/A Pace Car
73 Opel GT
73 bronco

 

Just because GM discontinued them does not mean parts are not available! (meaning gears up to 4.11, series 3 carriers and other goodies.)

PS For $500 I can get two 10 bolt 3.43 rears. Hmmmm... I wonder which one is better.

Miles


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88 427 Camaro
12.18 @ 113mph 1.75 60ft
Currently installing 3.73's into my 9 bolt (YES,it is a 9 bolt & YES they are 3.73's, not 3.70. 4.11's to follow soon )
www.koolmeister.com

 

umm, in case you don't know about them, 10 bolts also came with 28 spline axles. it began in late 88.

 

Zippy, check your part numbers again. The 10-bolt uses the same 26 spline part number up to 1989. In 1990 the part number changes, which to me means 1990+ uses 28 spline axles.

9-bolt parts are still plentiful and available in Australia. But shipping is a problem...


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1991 Camaro Z28
5.7L 5-Speed (originally 305)
13.23 @ 107.62 MPH
Southern California
Member: SoCal 3rd Gen F-Bodies
Webmaster: SoCal F-Bodies
-=ICON Motorsports=-

 

i actually have checked the numbers. according to our part numbers at work 4.3 s10's with stick, astro van's, and late certain v8 camaro's in 88 with 10 bolt got 28 spline's. it wasn't on all until 90.

 

Kevin, they started changing over the 10-bolt axle splines in late 88; some applications, probably the high volume fast movers like the 2.73 drum setups would have been the first ones to get the new parts. 89 is the worst year, there were some of the old ones still mixed in with the new ones in their stock, so there's a mixture of them out there. The changeover wasn't complete until sometime in 90.

Besides the number of splines, what is the axle diameter in the 9-bolts? That changed along with the spline count in the 10-bolts: the 26-spline axles will slide right up into a 28-spline carrier, without engaging of course.

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"So many Mustangs, so little time..."
ICON Motorsports

 

I have a 9 bolt with 3.73 gears from Reider Racing, they carry all the parts you'll need. They have a website but it doesn't list all the stuff they have, you'll have to call them.