The tach needle on my 327/350 "bounces" when reved up and does not operate smoothly. Does this mean that the unit itself is bad or could it be just a wiring or cable problem? If it's the unit, recommended vendor for replacement or repair?
-
-
Re: tachometer
Try cleaning and lubing the cable first. To remove the cable you will have to remove the housing from the tach end ( the hard way, naturally). There is a special graphite based lube for speedo and tach cables available at any parts store. If the cable is really gunked up with old lube, you may need to remove the hopusing and flush it out as well. This will likely solve your problem. May still not be as smooth as an electronic tach, but that should take most of the bounce out of your needle. -
Re: tachometer
Richard this may not solve your tach problem but to extend the life of your distributor shaft and the tach drive gear I also recommend removing the tach gear drive and cleaning the cavity and installing new lubricant.
If you really want to do a through job remove the distributor and disassemble it and repack the top cavity with lubricant and a new seal. Most likely you will find old dried caked lubricant needing replacement.Comment
-
Re: tachometer
Richard-----
Very often, the problem which you describe is caused by deficiency in the dampening mechanism in the tachometer head. Corvette mechanical tachometers are not direct drive type units and use a magnetic type of drive. Dampening is required in this set-up to keep the needle from doing what you're experiencing.
However, like the other responders, I also recommend that you check and service the drive gear and cable first. You should do this just as a matter of routine service, anyway, so you won't have lost anything if it does not cure the problem.In Appreciation of John HinckleyComment
Comment