I assume all thirdgens, 82-88, were equipped with rear disc dust shields. I know that some 9-bolts in 89 had the dust shield while others didn't, so how about the 89-92 10-bolt (or for that matter the 93-97 version)?

JamesC

 

No dust shields on the 89 3.45 9 bolt, I had laying around a few years ago. No dust shields on the 10 bolt in my 91 Formula either.

FWIW

 

All 9bolts I have seen have a dust shield or a spot where it was on the bracket. They were held on by very small spotwelds.
10bolts I hve seen did not have them.

 

My 1989 9-bolt with the the PBR brakes has the dust shields...check picture.

I also agree with the two spot welds, One weld broke on the left side and had a heck of a time chasing that rattle down.

 

I'm interested in the 10-bolt. According to my Parts and Illusration Cat., the 90-91 (and I assume 92) cars weren't equipped with the shield. Anyone with experience with a 89 10-bolt with PRB's?

JamesC

 

No such combination...PBR rears brakes only on the 1989 9-bolts.

 

I do not think my 89 had the dust shield either...

Of course its the 9 bolt... And I agree that 1989's typically did not have the disc brakes with the 10 bolt... It may have been available overseas, but not in the US.



John

 

Sooo, 89 is the single year where disc brakes were unavailable on a 10-bolt? Never entered my mind.

JamesC

 

Was the 10-bolt offered with discs between 87-90? I've never bothered to research it, but it seems like usually every performance oriented (LB9, L98) V8 from 87 to 90 came with a 9 bolt. I can't honestly say I've seen a 10 bolt with discs in the 9 bolt years.

 

According to the info below, the 9-bolt first arrived in 85. My 85 10-bolt was equipped with discs.

https://www.thirdgen.org/forums/faq-...now-about.html

JamesC

 

That's accurate, the 9 bolt was used in some 85 T/A's. From what I've read it took another year or so to show up in the Camaro. I've seen a couple 86 Z28's with 10 bolts with iron caliper discs, but from 87-90 I'm not sure.

 

Im thinking there was a TSB about a brake "moan" when backing slow in reverse. the newer redesined bracket you have "I think" is a result of that.
The orginal (1st des) 9bolt bracket w dust shield was a tad thinner and flexed a bit much. pic below

I will check my 89 formula 350 vert and see which are on it..
**Edit*** my 89 350vert has second design and my 89 350 ttop has the first design. they are 10,000 ish apart on the vin numbers

I like your sticker on the 9bolt. I need 3 of them !!!
And I don't think I have ever said this to another man but your rearend looks nice......

 

< There was no Blush it was the closest I could find... I was going to post something off the deep end about your rear end and how I never checked under your chassis, but I decided it was not appropriate, however I decided to let everyone know that I was trying to practice restraint.

LOL.

John

 

Good boy, John!

 

WOOF! (wags tail) pant pant pant

I'm in a good mood today...

 

Are you saying that only '89s had PBR calipers on the rears? Not so. I have PBR calipers on the rear brakes of my car, and they are stock. From what I've read, all '91/'92 GTAs have PBR calipers for rear brakes. To answer James' question, I have PBR calipers and do not have dust shields on my car. The entire rear end (incl. brakes) is stock.

-Eldon

 

I think what he was trying to state that...
1988 - PBR's used only on 1LE (9 bolt rear axle)
1989 PBR's only used on 9 bolt rear axle
1990 PBR's used on both 9 bolt and later 10 bolt rear axle
1991 - 1992 PBR's used on 10 Bolt rear Axle.

That's the trend that I have seen. I do know that the 9 Bolt was dropped in 1990.

John

 

Correct,
From what I have seen the 9 Bolt was first used on the LB9 & L69 Trans Am's in 1985, then used on the Camaros & Firebirds in 1986 with the LB9 or L69. In 1987 - 1989, All L98 & LB9/M5 cars got the 9 Bolt. Not sure about the LB9/A4. In 1990 it was on all early LB9/M5's and L98's from what I have seen, then Mid Model year the axle was dropped for the Saginaw 10 Bolt.

Not saying that they do not exist, but I have never seen a LG4 or L03 with the 9 Bolt, Nor any V6 cars (except the TTA in 1989).

Apparently (and from what I have read) the 9 Bolt was more Efficient for EPA regulations. Thus the limited usage. As ECM's became more advanced in 1990 it was no longer necessary to use the more expensive 9 Bolt over the Domestic 10 Bolt. Of course more efficient may have been lighter, I never bothered to actually weigh the axles. Weight was a huge concern for 3rd Gens.

 

John,

Any info on 10-bolts and rear discs, say, 87 and 88? Or were all rear disc cars in those years 9-bolts. I did find the following (for what it's worth):

G92 "seems" to be the key for rear discs 87 through 89 (at least on Camaros). Comments?

1987: G92 available only on IROC-Z with 5.0 TPI (LB9). All 1987 350 TPI (B2L) IROC-Z's came standard with the 3.27 BW rear end and everything that was included with G92 but did not have the G92 RPO code because it was mandatory; this changed in 1988 however when a 2.77 BW rear was standard and G92 had to be specified to get the 3.27's. All 1987 350 TPI (B2L) IROC-Z's required J65 rear disc brakes, G80 limited slip differential....

1988: G92 code was now available on the 350 (B2L) IROC-Z and now had to be specified to get 3.27 rear end (was standard in 1987) as a 2.77 rear was now standard on the 5.7 TPI. J65 rear disc brakes, G80 limited slip differential....

1989: G92 also required the following options: 5.7 TPI motor (B2L) or 5.0 TPI motor (LB9) with 5 speed (MM5) manual. 16 inch wheels (N96) P245/50ZR-16 Goodyear Gatorback tires (QLC) Limited slip differential (G80) Rear disc brakes (J65)....

JamesC

 

I had an '85 T/A with the 9 bolt. It had drum brakes.

I have had several '86 LB9 Irocs, with and without rear discs. All of them are 10 bolts and I have not seen any '86 Camaro with a 9 bolt. The 9 bolt seems to have been T/A-only for the '85-'86 model years.

Also, I had an '89 IROC that was an original LB9/ 5speed car. It had a 10 bolt with drum brakes an 3.08 gears. As far as I know, the only Camaros that got the 9 bolt were disc brake equipped.

Oh, and the PBR brakes I pulled from a '92 10 bolt did not have dust shields. It was a high-mile car though, so they might have been removed at some point.

 

To be honest, I really do not know, its just what I have observed. And yes there appears to be a correlation to the G92, however its not definitive.

All of the 9 bolts I have seen had J65 (Discs) However IIRC there are references in literature like Haynes/Chilton shows 9 bolts with the drums. However I have never gone thru the parts & Illustration catalogs to try and decipher it. It may be an interesting project some day, just too busy to really go thru it right now with real life.

 

Curious about the disc/year question, I posted the following link on the Brake forum:

https://www.thirdgen.org/forums/brak...88-89-ten.html

After 128 hits without reply (at the moment), I'm beginning to believe that 10-bolts were equipped with discs, 82-86, and 90-92. In the intervening years, 87-89, if the car was equipped with discs, they were on a 9-bolt.

JamesC

 

My 85 IROC HO L69 came with a 5 speed and 10 bolt with iron calipers.

 

I have an original 1987 TPI 350 TA WS6 with automatic transmission and four wheel disc brakes. I read that the 1989 TA with disc brakes had improved PBR rear calipers and emergency brake that work. What parts do I need to install the better brakes on my car. New dust shield, brackets, etc?

 

Remove the braking system from the 89, to include the backing plates, and install on your 87. Though the following link is for 10 bolts, the braking system is identical:

https://www.thirdgen.org/forums/faq-...iscs-89-a.html

JamesC

 

My 84 has dust shields

 

As far as I know, all the 82-88 cars had them. Some 89+ car were so equipped, some weren't.

JamesC

 

only on the small brakes 10.5" have I seen the shields... not on any of the larger ones.

 

Info and pics in the following link:

https://www.thirdgen.org/forums/brak...st-shield.html

JamesC