I bought a 2000 Z28 with 29k miles a few months ago. Went underneath it to install an SLP DS loop and noticed my DS is rusted to crap. I thought these cars had aluminum DS? If so I wonder why they would have changed to a steel shaft on a bone stock car??? Any ideas.

 

A4s' with 2.73s' came with steel driveshafts.

 

My Formula came with a steel DS, it's an A4 with 2.73 gears. Aluminum was an option that came with the 3.23 or 3.42 gears. I think all SS's and WS6's came with aluminum but not sure on that. Stock for stock I'd take a steel one though so it bends less.

 

Ok, I didnt know that. Mine is an A4 2.73 so it must be factory steel. Thanks guys. I learned something new.

 

They are both weak, aluminum just has better harmonics for the higher rear end ratio.