Topic: Fastback Quarter Vent (air extractors) installation: Torque on hardware

[Angela]

How tight must the hardware be tightened to hold the body-color (outside) fastback vents to the body? There are five 1/4-20 threaded rods that extend from the vents, through the holes in the body and held with cupped washers and nuts. The torque spec for these nuts I believe to be 15-25 in*lbs. However, I find two problems tightening these nuts: (a) tightening the nuts causes the sheet metal on the interior to bend "bow" slightly, which makes it difficult to get a good torque reading and (b) when I tightened them to 20 in*lbs the paint cracked off of the vents and I can see hairline cracks in several of the 1/4-20 stud mounting locations.

How tight is tight enough? 20 in*lbs seems like nothing! Perhaps the vent was cracked before-hand and I didn't know it. Regardless, I'm looking for some feedback as to how others tighten these things. This would be no big deal if they were easy to get at once the interior is installed. :-(

[CharlesTurner]

I would just snug them up by feel and watch so that there are no waves in the metal or parts.  It's not going to be an exact science.

[Angela]

Thanks Charles. I have a tough time when I don't have a spec to follow.... I see your point that it's not rocket science.... it's just that one person's "feel" for being tight enough could be totally different to another person. :-)

Can you or anyone comment as to whether or not these things commonly come loose? In short my concern is to make sure they're tight enough such that they don't come loose while I'm going down the road, which is then likely to scratch up the exterior paint. It seems like a tremendous pain to remove all the interior panels to regain access to the nuts if they come loose and I have to tighten them.

Perhaps it's wise to use a little blue loctite???

[CharlesTurner]

I think if you're worried about them coming loose, you could always use another nut on top as a lock.  I believe these are the speed-nut style, so using loc-tite is not going to help as there are no threads to fill and lock.  Maybe some windshield urethane sealer would set them tight too.

Personally, I would just snug them up and not worry about it.