So I noticed a scratch on my Coast aluminum driveshaft. I think it came from the bar pictured, which I have since taken off. It's not deep at all. I can just barely feel it when i run my finger over it and it's not even deep enough to catch my finger nail. I don't know how long its been there but I did a pdx at Mid Ohio last week and I'm still alive. Do you think that I need to worry about it?

 

As you probably know, it doesn't take much to put a drive shaft out of balance. And the times I've dinged a drive shaft it was pretty obvious by the dent as well as vibration.
However, there's always a chance it could be slightly out of balance that you wouldn't feel vibration, but still put added pressure on trans bearings.
Only way to know for sure is take it off and to a shop and have it checked. I assume they can balance aluminum like they do steel drive shafts.
Did you bottom out so it hit that bar?

 

I wouldn't worry about it, but you can have it checked won't hurt.

 

I honestly don't know how it happened. When I installed the shaft I flattened out that hump in the tunnel so I know it wasn't that. I don't notice any vibration. Had it up to 130 at mid ohio and there was no problem.
I just hope it's not weakened. I'm most worried about it breaking. I just looked at it again and its just barely deep enough so I can feel it but when I drag my finger nail over the spot it doesn't snag.
I really don't have the cash right now for another $600 driveshaft.

 

I agree don't worry about it. If it was a dent or a ding I would say you might feel it.

 

ok I'll let it go. I just don't know how thick that aluminum is and I was just worried about the strength of it but I doubt such a thin scratch would weaken it.

 

I'm sure it's fine. I bottomed out right after I got mine installed and hit a bolt, scored it pretty good (can feel it and will catch my fingernail). I haven't taken it easy on the car at all, and it's been 4 years, and the driveshaft is still fine. In fact this weekend I drag raced against a buddie's M3 (he had ~80HP on me...so we know how that ended). So that driveshaft has been tested over and over again and hasn't failed yet.

 

My drive shaft actually hit something and put a pretty good scratch in it. Way worse that what you have in yours. I took it out to see if it need to be rebalanced or replaced. It was totally fine. I wouldnt worry about that little scratch you have in yours.

 

cool, I won't worry about it then. Thanks