It is the lower alternator bolt. It seems the stupid PO put too long of a bolt in so it just bottoms out without clamping the alternator down. This causes the alternator to be crooked and is destroying the bearings.

I just need the thread size/length so I can go to the hardware store.

Thanks guys and gals!

 

Generally the part number is the size.

Does M10x10mm sound like the right size?

That would make the adjuster bolts (0880 and 0835) M8x80mm and m8x35mm. You could check a few other bolts and their part numbers to see if that system works, but I think Mazda applied it to Miata parts.

 

From what I understand, the naming convention is such that the last 4 digits of your part number is your bolt size.

I believe the first two digits (in this case "10") suggest that this is an M10 bolt. I believe that the last two digits (in this case also "10") suggest that this should be a 10mm bolt. Unfortunately, that 10mm length seems unreasonably short for a M10 bolt - which throws off the whole convention thing. Perhaps it should be a 100mm bolt? I can't picture the bolt in question in my head - on the NA cars, there is an alternator bolt that seems like it was 150mm long.

The bolt on the chart above it is a 1020 Bolt, I would think 20mm would be about the minimum length to secure a stamped metal bracket to a cast metal part.

 

It has to be at least 100mm long... hm M10 does sound right. I'll just buy a couple different lengths.

 

Here's a whack idea: cut down the bolt that you have!

 

It is a whack idea, because his current bolt obviously has a shank to it. That's why it's bottoming out before it's tight and cutting it down wouldn't help... unless you want to run a die over it and thread the shank which sounds like a lot more work than getting the proper hardware.