missing alternator bolt on 1995 c4 what size?

[starbuck]

I started getting a squeeling sound form under the hood and thought maybe the power steering pump or the ac compressor were going bad. Instead, I found that the short bolt which attaches the alterator to the rear bracket is missing!

Does anybody know the size, length, metric/SAE and thread of this bolt.

I can get to a parts store about a mile away on my bike (currently in 1-car hell) but I'm afraid if I drive the thing to the dealership 30+ miles away I'll F something up or loose the serpentine belt.
Thanks

 

[tcxd40]

Metric bolt, 13mm head maybe 15mm can't remember. Has built in washer face. You can use a 8.5(strength) metric bolt from the hardware store just would have to buy a washer too. Threaded portion of bolt is about 3/4 long.