87transam5.7tpi

Hey guys I did a couple of search's on this and everything says my car should have an aluminum driveshaft. well it doesn't, and if the owners before me switched it how much is that holding me back performance wise? just wondering. thanks

Josh

Justins86bird

Why do you believe it should be aluminum? Only 1LE cars and cars with RPO JG1 got aluminum driveshafts.

mystikkal_69

iTrader: (2)

not true. my 88' iroc has the aluminum driveshaft(genuine GM), alum spare, PBR rear brakes, and no PBR fronts??? why did they stop there? this sucks.

keen88gta

For trans ams of that year only the GTA came stock with aluminum. It was optional on all other models.

87transam5.7tpi

mine is a GTA, so how much is not having one holding me back? they must have replaced it.

keen88gta

It is a matter of weight. Your steel driveshaft is much heavier than an aluminum. So not only do you have extra weight the loss of HP between your flywheel and your rear wheel will be greater.

JAY87GTA

The only way our cars came with an aluminum driveshaft is if the original owner took the car in an complained about a harmonic vibration. As was stated above, only 1LE and JG1 cars came from the factory with an aluminum shaft. You will not feel a performance difference, just less vibrations at high speeds.

keen88gta

oops wrong information. The JG1 didnt become standard in GTA's till there inception year( that is the year that Pontiac made GTA official) All GTA's from 88 on will have the RPO code JG1.

Mike-92GTA

B]All GTA's from 88 on will have the RPO code JG1.[/B]

Correction Keen88GTA, Not every GTA from 88 on up had the JG1 aluminum "propeller". i.e. just for '92's, 62 of the 226 (or 508) were the exception.

Source: GTA Source Page
http://www.gtasourcepage.com/92RPOFigures.html

fly89gta

iTrader: (1)

my GTA has the code for hte aluminum DS and its not a 1LE, regular 89 GTa...

iroc22

It was an option to get JG1, it wasn't standard or mandatory for the GTA.

The only way a non Formula/GTA/1LE could get a aluminum driveshaft is if the steel one was replaced on warranty.

cg91ta

So then my 91 Trans Am with the rpo JG1 should or shouldn't exist?

Justins86bird

If you have JG1, then GM gave you a Al d/s
If you have 1LE, then GM gave you a Al d/s
If you have neither, then GM gave you the steel d/s
*You don't have to have a 1LE to get the Al d/s. JG1 was the option on non-1LE cars.

JAY87GTA

And some cars may have had the driveshaft switched to aluminum under warranty because the original owner complained of vibration. So if you don't have RPO 1LE or RPO JG1 and you have an aluminum shaft consider yourself lucky. And please quit trying to tell everyone they should have the aluminum shaft because you do!

breathment

ya. just because u have JG1 doesn't mean u have a 1LE, it just means that whoever bought the car asked for an AL driveshaft.