I have an convertible , my first question is how do I tighten the windshield mirror it's lose and the second one is when I'm driving the tach  is reading  close to speed I'm driving...doing 50 tach reading 45 to 50 rpm. Is this normal?

On the mirror, it depends on where it is loose.There are a couple of different pivot points, and any of them could cause it to flop. There is a ball/socket that is part of the mirror itself, and that attaches with a screw tot he other part of the hanger that is screwed to the windshield header. The top piece(at the header) can be removed, and a screw inside tightened to help. If the mirror itself is flopping on the ball/socket where the arm comes out of the back of the mirror, that will require removing the glass to try to tighten it up inside....

Someone here just replaced the glass in their mirror...perhaps they took some pics....

On the tach, the problem is either going to be with the tach filter, or the gauge itself. Try disconnecting/bypassing the tach filter and see if that makes any difference.




|UPDATED|6/23/2014 9:39:00 AM (AZT)|/UPDATED|


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Joel Adams
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"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"

Sometimes you can remove the bottom stops  that keep the glass from going to low & drop the glass in the door . This gives you enough room to tighten the mirror . This is a lot easier than removing the glass from the door.  The earlier C-3's are pretty tight, but I think it will work on a 75.

|UPDATED|6/23/2014 11:09:21 AM (AZT)|/UPDATED|


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Alan, he's talking aboot the inside rear view mirror...the one in the center area of the windshield.

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Joel Adams
C3VR Lifetime Member #56    
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"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"

|UPDATED|6/23/2014 4:37:56 PM (AZT)|/UPDATED|


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"Let them that don't want none have memories of not gettin' any."
- Brother Dave Gardner

Where would I find the tach filter

Normally not too far from the distributor.It will be in the wire that goes to the "Tach" terminal on the cap. The filter willa lso be bolted down to something so it will be grounded...not sure exactly where it would be on the '75, but if you follow the tach wire down from the dist., you should find it.

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Joel Adams
C3VR Lifetime Member #56    
My Link


(click for Texas-sized view!)             NCRS

"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"

The filter should be bolted to the intake manifold. You can disconnect it from the "tach" output of the distributor and bypass it by plugging the wire from the firewall right into the distributor. It may be the tach board is bad as Joel has said. I replaced mine last year. Not a difficult job but it takes some time and patience to do.

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