I'm curious which cars with rear drum brakes received aluminum drums (J42) in place of the cast drums (J41). None of my reference materials delve into this subject. I've owned three 1987 Z28's (one with the IROC-Z option). All three had J42.

Willie

 

I have J42 - Aluminum rear drums.

 

So do I I have the only 1992 GTA with that option as a matter of fact!

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[This message has been edited by 92GTA (edited January 14, 2001).]

 

Willie, 1983-84 L69 optioned Z28's that did not get rear disc brakes got J42 aluminum drums. I do not know about other years.

 

I always figured it had to do with the wheels... 16" or aluminum or something along those lines...

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Willie 86 IROC here mines also got the J42 brake option.

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Wow. These seem to be more common than I thought. None of my cars have them. Hell, I've never even seen them. Does the inside of the drum have a steel liner or does the pad run right on the aluminum?

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Just thought i'd note that my 92 Z vert has iron drums, J41, so all 16" wheel cars didn't get 'em.
I remember some chatter a while ago about on 16" IROC wheel cars, they either had AL drums alone, or FE drums with those thin spacers.
I have no idea if i have those thin spacers behind my wheels.
...ed

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My 1986 Z/28 has J42.

 

I thought the base models would get iron drums and the Z28/Trans Am models would get aluminum drums. But then Ed posted, and there goes that theory.

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Since this has resurfaced i figure i'll add that i do have the thin spacers w/ my iron drums.
I should point out that my Z28 vert only came w/ F41, so maybe FE2 cars got AL drums?

 

My 83 L69 Z28 has Al drums; my little bro's 84 LG4 Z28 head Fe drums. My other late little bro's 87 MC SS had AL drums. Every L69 vehicle I have seen came with them; I've sort of always assumed that at least, L69 = Al drums if not disks just like L69 = 3.73 gears, but beyond that... who knows.

They have an iron or steel liner inside the Al. The lug flange is thicker on the Al drums, so the Fe ones got the spacers, 1/8" or so thick.

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Hmm, when I get home tonight I'll have to check. IIRC both my '84 L69s do not have Al drums, but rather Fe drums. As I said, I'll check tonight and if possible get some pics of my SPIDs.

edit: Yup, I was right, not all L69s got Al drums. Neither of my L69s have J42.

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[This message has been edited by MRZ28HO (edited May 11, 2001).]

 

My 85 MC SS w/3.73's had the steel drums. My 85 Z28 lg4 also had the steel drums.

 

Ed, I never thought about it but my 92Z28 has the iron drums on the back. Guess when I need new drums (probably sometime in the the year 2100!) I'll get the aluminum ones and save some weight and rotating mass


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I got a 1991 Z28, LB9, 5-speed, it's an F41 car and it has "J42" aluminum drums. No N10, G92, just G80 3.08 and J42.

 

Reviving a thread that's 10 and a half years old. This has to be a new TGO record!

 

^^ I doubt it...I think I've seen worse!!

I always love seeing the revival of ancient threads, and seeing everyone's older sigs...either they're basic looking, 8 feet long, etc.