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History / OriginalityGot a question about 1982-1992 Camaro or Firebird history? Have a question about original parts, options, RPO codes, when something was available, or how to document your car? Those questions, answers, and much more!
I'm curious as I believe 1988 was the first year the JG1 was an option what was the earliest one built? From what I've seen towards March thru June of 88 it was more widely used, I just saw this one online that should be an late January built car. Does anyone have one under a 147 vin? JGI but not a G92, hence 2.77 axle ratio
Was JG1 Alumn. Driveshaft for weight savings (CAFE) or performance?
It's believed to be for CAFE. You will find them on the heavier ThirdGens that are well equipped. My first Trans Am, a 1988 with the LB9/MX0/CC1, digital cluster and GU2 2.73 gears, came with the JG1 on the SPID. That's not considered a performance combo to support JG1 was for performance reasons.
I pulled one out of a loaded 85 86 1 owner totaled Trans Am back in the day. (early 90s) My old memory may be fuzzy but I know the car also had a spoked aluminum spare.
Think they were 1st used in the 84 C4 vet then trickled into the f-body but unsure exactly what year. I know I have the info saved someplace
Here is the 84 corvette prototype/production chassis with aluminum shafts in it. 1984 Corvette Prototype Chassis Going Up For Sale - Chevy Hardcore
It's believed to be for CAFE. You will find them on the heavier ThirdGens that are well equipped. My first Trans Am, a 1988 with the LB9/MX0/CC1, digital cluster and GU2 2.73 gears, came with the JG1 on the SPID. That's not considered a performance combo to support JG1 was for performance reasons.
Thanks. I know the light weight wheel for the spare was part of this, too. Cross lace wheels also saved weight. Some of the GTAs were really close to CAFE bracket limits, maybe even gas guzzler taxes. Some Camaros, too.
I have a buddy who's a huge third gen nut and had a gazillion of these things. He was saying the aluminum drive shafts aren't what they're cracked up to be. Says they are known for tossing weights and vibrating. Says the weights were basically taped on with a 2 sided tape?
I have a buddy who's a huge third gen nut and had a gazillion of these things. He was saying the aluminum drive shafts aren't what they're cracked up to be. Says they are known for tossing weights and vibrating. Says the weights were basically taped on with a 2 sided tape?
I have a buddy who's a huge third gen nut and had a gazillion of these things. He was saying the aluminum drive shafts aren't what they're cracked up to be. Says they are known for tossing weights and vibrating. Says the weights were basically taped on with a 2 sided tape?
Weights are welded on and some type of epoxy(?) is put on over them.
3rdgens, smaller diam but thicker wall material
4.5 (98-02)gens, larger diam but thinner wall material
For whatever reason, all the B4C 1LEs I've seen had steel DS.
The majority of the GTAs from 1987-1992 received the aluminum driveshaft. Even in 1989, when there was a brief period where they had room to allow the 350 with factory T-Top combination, the majority of the GTAs received the aluminum driveshaft. Obviously, the GTA was the heavy car and generally loaded with options. My 1992 T/A with the LB9/MM5 has the steel driveshaft. Compnine shows all of them did with that powertrain in the convertible and only the automatics in the convertibles got the aluminum driveshaft. Giving further support that weight and certain combinations triggered the option.
The majority of the GTAs from 1987-1992 received the aluminum driveshaft. Even in 1989, when there was a brief period where they had room to allow the 350 with factory T-Top combination, the majority of the GTAs received the aluminum driveshaft. Obviously, the GTA was the heavy car and generally loaded with options. My 1992 T/A with the LB9/MM5 has the steel driveshaft. Compnine shows all of them did with that powertrain in the convertible and only the automatics in the convertibles got the aluminum driveshaft. Giving further support that weight and certain combinations triggered the option.
Yeah, but I just find it interesting that B4C 1LEs have steel DS. My guess is that it has something to do with durability?
I was looking up the N64 alum spare and also started looking at the Alum Driveshaft. Often found together and on heavy cars. In early years, T-Top cars seemed to have them. In my number crunching, all 1LE cars had them (unsure on B4C). Not a performance item, but the option was included in the 1LE cars for weight reduction - hence conclusion it was a performance option.
I have owned two 1988 Irocs with the 5.7. I am unsure of the build date of my 1st ‘88, but it did have the JG1 aluminum driveshaft RPO. The last six on the VIN were 120651. My current 1988 is equipped with the aluminum drive shaft as well. Last six on it are 181852. It is a June of 1988 build. Both have t-tops and were fairly well optioned, with my current ‘88 being a highly optioned example. Would believe mine were equipped as such more due to weight than performance!
Last edited by 1988 Iroc 5.7; 06-19-2021 at 04:08 PM.
Two things:
-The FireBirds often received options before the Camaros did (Pontiac falls in a higher Tier than Chevrolet... which is the lowest Tier).
-The Steel Drive-Shaft was considered to be the better, stronger, more heavy-duty Part by GM... It's no surprise that B4C/ 9C1 vehicles have them.
Two things:
-The FireBirds often received options before the Camaros did (Pontiac falls in a higher Tier than Chevrolet... which is the lowest Tier).
-The Steel Drive-Shaft was considered to be the better, stronger, more heavy-duty Part by GM... It's no surprise that B4C/ 9C1 vehicles have them.
Well, you see where being higher Tier got Pontiac……CANCELLED! Being lowest Tier isn’t all bad🤣🤣🤣
anyone know the correlation between aluminum driveshafts and aluminum drums on the rear brakes? I have a '91 T/A with aluminum drums, driveshaft and spare tire. It is an automatic LB9, with T-tops, so most likely all for weight savings.
I worked at GM Tech Center back in the late eighties/early nineties, and they were obsessed with CAFE regulations. They swore no GM car would ever pay the gas-guzzler tax.
anyone know the correlation between aluminum driveshafts and aluminum drums on the rear brakes? I have a '91 T/A with aluminum drums, driveshaft and spare tire. It is an automatic LB9, with T-tops, so most likely all for weight savings.
I worked at GM Tech Center back in the late eighties/early nineties, and they were obsessed with CAFE regulations. They swore no GM car would ever pay the gas-guzzler tax.
I don't think there was an RPO for alum drums was there? I did a cross check on JG1 and N64 and could certainly see a pattern with heavy vehicles. Unless it was a 1LE car, you needed a heavy weight option car to get the aluminum parts. I ran a pile of numbers on a N64 post if you want to read them. If there was a alum drum code ... I could cross check that.
I don't think there was an RPO for alum drums was there? I did a cross check on JG1 and N64 and could certainly see a pattern with heavy vehicles. Unless it was a 1LE car, you needed a heavy weight option car to get the aluminum parts. I ran a pile of numbers on a N64 post if you want to read them. If there was a alum drum code ... I could cross check that.
Some quick stats from my N64 lookup. JG1 was paired up with N64 Alum Spare, J42 Alum Drums, and came with heavy cars like CC1 T-Tops and was used in 1LE packages.
06-12-2021, 10:07 AM
