pontiacstogo

Did the 1994 1LE's come with a steel or aluminum driveshaft? There seems to be conflicting information out there - anyone know for sure?

shoebox

Aluminum.

pontiacstogo

Weird - managed to get my car up on some ramps today and my driveshaft is definitely steel;



It's possible that the shaft was swapped out at some point prior to my ownership.

shoebox

I could be wrong, too.

Injuneer

The 3rd Gen 1LE had an aluminum DS. The part # is listed in the 4th Gen FAQ. The references I have do not list the aluminum DS for the 4th Gen 1LE package. There was a technical service bulletin (TSB) that provided a 1LE aluminum DS as a warranty replacement for the steel DS (all V8 models) if the customer experienced drivetrain vibrations at high speeds. The issue was the low critical RPM of the stock steel DS. It only reached the vibration RPM at very high road speeds (stock rear axle ratios), but at much lower road speeds w/ a swap to a 3.73 or 4.10 rear.

Possible source of confusion - It was widely publicized that the fix was a free 1LE aluminum DS. Perhaps in actuality, the replacement part was the 3rd Gen part, but everyone assumed it was a 4th Gen part.

Just a thought.

pontiacstogo

I think you're onto something there Fred. I think too that because the aluminum driveshaft was part of the 1LE package on the 3rd gens it's just assumed that it was part of the 1LE package on the 4th gens as well. In lots of ways the 4th gen 1LE's were a lot less 'special' than the 3rd gens. I suspect the 4th gens were such a leap over the 3rd gens in overall performance that GM didn't need to do as much with the 4th gen 1LE package to make the Camaro competitive on the track.

I'm chasing down some general drivetrain harshness and noise on my car - I don't expect it to ride or sound like a Cadillac, but it whines, bangs and vibrates more than I think it should. I know a lot of people switch to the LS1 aluminum driveshafts, but I think I'm going to have my steel one rebuilt and balanced.

Injuneer

The steel DS may improve with balance, but the problem is not balance. The problem is the "critical speed" issue. That's a factor of length, weight, etc.

The LS1 aluminum DS has limits as well. It can't take the torque produced with a power adder. I have friends who have broken the LS1 DS with a mild boost S/C LT1, and broke a Lingenfelter 3.5" aluminum DS with a more aggressive S/C (700-750 HP) LT1. The reduction in drivetrain loss with aluminum vs. steel can be seen in this dyno comparison:

Drivetrain Modifications #1

He also tested the 1LE vs. an ACPT carbon fiber DS:

Modifications #10

I had a failure with an ACPT 4" CF DS. And it happened when the shop that built the engine, running on a basic "keep it running" tune, was driving the car about a mile to a paint shop to have my WS6 hood installed. The front metal yolk assembly broke free of the CF tube, due to an adhesive failure Took me 3 months to get my money back from ACPT, and only after I bypassed the "sales" dolts and went one-on-one with an engineer.

My choice is Mark Williams 3" chrome-moly. Heavy, but still a bit lighter than an equivalent carbon steel DS. But it has to be strong to handle 800 lb-ft. Good info here:

https://www.markwilliams.com/driveshaft-tech.html

pontiacstogo

Thanks for the info. I did some reading originally on the problems with the LT1 steel shafts and it sounds like that may be compounded on my car given the 4:10 rear it has. My engine is mostly stock (CAI, Hypertech tune and thermostat) so I don't think I'd have any horsepower related problems with an aluminum shaft. More research required!

Injuneer

Definitely the 4.10’s if the vibration sets in at ~65 MPH.

Bad AZz Z28

I know this post is a few years old, but I just
stumbled onto it. Both my 94 1LE and my friends 94 1LE had steel driveshafts.