I lost the back alternator bolt that holds the alternator to the bracket. It's the shortest one of the 3 bolts. What is the size/threading on it?

 

I'm not sure what size the bolt is, but where did you lose it? Did you just drop it and couldnt find it? There is an area in the fron suspension that catches alot of stuff that i drop, maybe it's in there...

Oh and I've been running 3 of 4 alternator bolts for months now with no probs, it's plenty secure in there.

 

i didn't drop it, it fell out some where on the road. I have been driving the car pretty hard lately and apparently it fell off because of the beating it's been taking. I just popped my hood recently and i noticed it was gone and the other one was about half way out.

 

Although the heads on the bolts require a metric wrench, for the most part the threads are standard. I'd go to a local hardware store and spend a few minutes.

 

The bolts that screw into the back of the alternator are M10x1.5x20.