[dataway]

Should the over center springs hold the headlight doors in the closed position with no vacuum lines attached to the actuator at all?

I've heard of people "adjusting" the over center spring bracket to accomplish this ... but I see no way to adjust it, single bolt, and a lip on the bracket to align it in one place on the rod.

Are the original springs often so spent they won't do the job anymore?

Right now, when I apply vacuum to the actuator the door moves up nicely, but soon as I release vacuum it slowly descends.

[rasilverbird]

Mine held the doors closed nomatter how long it was without vacuum.

[dataway]

Got it figured out. Didn't realize the adjustment is on the door side of the rod, not the spring side.
Was still having a hard time getting them to behave properly. Pulled it back apart and replaced the door bushings that I "thought" were good enough, with new ones ... works like a charm now. Just the tiniest bit of slop in those door bushings is all it takes to keep that over center spring from doing the job.

Jeez a person gets to be an expert with these things after taking them apart half a dozen times. With a shoebox of new parts and some cordless tools a person could probably make a few bucks at a Pontiac show getting peoples doors sorted out

[Greg Reid]

The system is rock solid when you pay attention to the details. That trapezoid shaped tab that the spring attached to isn't really adjustable, ie. no slotted holes or anything, but loosening of the bolts and moving it just slightly can cause the cover to rest too low or too high. I had to put a lock washer on one of mine to make it stay put.

[dataway]

I was amazed how short the pull on the spring was ... MAYBE 3/16" ... which means the tiniest change in geometry can really impact how it works. Weird that they didn't use a system with a longer pull and more of an over center "hump". Could be the rods are a bit twisted with long use. Just a single degree of twist would impact the function.

I noticed the addition of a small spring cures sag even with worn parts.

I basically adjusted the non-adjustable trapezoids, the rod support and even the door housing for as much spring tension as I could create (using the always adjustable clip nuts and large holes these components have) ... and then used the slotted adjustments at the cover end of the rod to get the door height right.

I should probably make some of those often missing upper door stops and install them.

[Greg Reid]

Good job on the bumper and grilles. Looks really good.