Loud Whining from (cold) Tach

[Jeffrey D.]

Hello all!
A very strange thing happened yesterday.
I've got a '63 SWC that sits most of the year here in Southern New Jersey. Yesterday's temp was in the low 20's, and I started the car to let it run/idle for a bit. Within about a minute of starting it, the tach needle raced up into the red line area and emitted a very loud, continuous, screetching whine,...but the motor was spining near idle speed. This has never happened before, and a tap or two on the accelerator pedal corrected it once, but resulted in erradic performance in that the needle 'bobbed/floated" off of the current rpm area,..then it once again raced way up to red line and whined loudly once more.

My first thought,..since this was a new cable when the car was restored about 15 yrs ago was that perhaps since it's SO cold, whatever lubrication that WAS there has either congealed or is totally gone.

Has anyone ever had this happen, and/or what is the fix for this?

Thanks to all in advance!
Jeff

[Dick W.]

Re: Loud Whining from (cold) Tach

The cure for that noise/erratic tach is to have it rebuilt. It will eventually lock up and break the cable

[Michael H.]

Re: Loud Whining from (cold) Tach

The cure for that noise/erratic tach is to have it rebuilt. It will eventually lock up and break the cable

Yup, Dick is right. It's not the cable but the tachometer itself. Pretty common problem.
The bushing in tha tach wears and the shaft goes into a speed wobble/shimmy mode when cold and usually won't stop until the engine is shut down/restarted.

[Jeffrey D.]

Re: Loud Whining from (cold) Tach

Michael and Dick,
Thanks SO much for your fast replies! It sounds as though you're both very confident in what is causing the problem and for me that works! ; )
The lousy thing here is that I paid someone (A very well know Tach "restorer") good money to rebuild the tach back some 15 yrs ago when I restored the car. Funny thing though,..when I got it back, the redline area was painted the wrong colors! This is a 327/340 car and although they painted within the correct area (7000 rpm range), the colors they used were red and dark red, instead of the (I think) correct yellow-orange-red that I've seen in original cars. Perhaps that was the first sign that something wasn't "kosher?" I did get 15 good yrs from it though! Now the hastle of rmoving the steerning wheel, dropping the column, and all those wires and bulbs,...yuk!

Thank you again!
Jeff
PS Any recommendations of who I should send the tach to for rebuilding and recoloring of the dial's red line area?

[Michael H.]

Re: Loud Whining from (cold) Tach

Funny thing though,..when I got it back, the redline area was painted the wrong colors! This is a 327/340 car and although they painted within the correct area (7000 rpm range), the colors they used were red and dark red, instead of the (I think) correct yellow-orange-red that I've seen in original cars. Perhaps that was the first sign that something wasn't "kosher?" I did get 15 good yrs from it though! Now the hastle of rmoving the steerning wheel, dropping the column, and all those wires and bulbs,...yuk!

Thank you again!
Jeff
PS Any recommendations of who I should send the tach to for rebuilding and recoloring of the dial's red line area?

There were two very different tachometer red line colors used for solid lifter cars in 63.
Early cars, built until some time around early 63 (January??) had colors of orange/maroon. This particular unit would be refered to as the "buzzer tach".
Later in 63 production, the colors changed to yellow/orange. No buzzer wiring connection.

I'm not aware of any instrument restoration people that supply this choice in colors for early/late 63 but I suppose someone probably does?? Maybe Joe Ray?

It's possible that the magnet and shaft/bushing assembly is still available?

[Jeffrey D.]

Re: Loud Whining from (cold) Tach

Mike,

This is an early 63, produced the 2nd week of Dec 62 AND it's a buzzer tach,..so perhaps the person that rebuilt it recognized that, but he painted the redline a normal red color and a maroon.
I'll do some research before selecting a proper rebuilding service.

Thank you again!!

Jeff

[Michael H.]

Re: Loud Whining from (cold) Tach

Mike,

This is an early 63, produced the 2nd week of Dec 62 AND it's a buzzer tach,..so perhaps the person that rebuilt it recognized that, but he painted the redline a normal red color and a maroon.
I'll do some research before selecting a proper rebuilding service.

Thank you again!!

Jeff

I have a pic of an NOS 63 buzzer tach that shows the correct colors and when I find it, I'll post it.

[Jeffrey D.]

Re: Loud Whining from (cold) Tach

Great, thank you!

[Michael G.]

Re: Loud Whining from (cold) Tach

Here is a picture of an original, unrestored '63 buzzer tach that has seen very little sun.

I hope this helps.

Mike

[Edward B.]

Re: Loud Whining from (cold) Tach

If the tach has not broken yet, it will! Previous posts are correct and a rebuild is in order.

[Jeffrey D.]

Re: Loud Whining from (cold) Tach

The serial # on my car is ...4097 and was produced in mid Dec, '62.
I've been reading a lot of archived posts some of which mention old restorer articles featuring early 63's with the high-rev tach/ color stats and apparently it seems a car as early as mine SHOULD have the red/maroon 6500/7000 "red line."
My car DOES have the buzzer screwed to the "Z" bar frame behind the dash.

I'm going to remove the gauge cluster (argggh!) and pull the tach to have it repaired.

Any suggestions on where to send it?
Many seem to be using Corvette Specialities of Maryland with good results.

Thanks,
Jeff

[William V.]

Re: Loud Whining from (cold) Tach

Jeff

I Had the same problem with my 64. its the tac. As in your situtation, it was very cold when it happened . I pulled over and reached under the dash and disconnected the cable. You said the tack was rebuilt 15 years ago. So figure you have a 15 year old tach that needs work. I suspect the problem is from sitting for a long time and parts drying up. The same thing can happen to the speedometer.

Bill

[Michael H.]

Re: Loud Whining from (cold) Tach

Great, thank you!

Here's an NOS early buzzer tach. Colors are definitely not yellow/orange as seen on later 63's and all of 64. I would describe the colors as orange/maroon. (I hope the link works)

https://www.forums.ncrs.org/attachment.php?attachmentid=14818&d=1229487292&uid=6766

[Jeffrey D.]

Re: Loud Whining from (cold) Tach

Michael, thank you so much for that pic! Actually, i found it here in the archives about an hour ago ; ) Much appreciated though!

Bill, thanks to you for your reply! Good point about the 15 yrs old thing and the car sitting which is all it does

I'm considering pulling the speedo AND tach for rebuild. Come to think of it, the trip meter doesn't reset.

Many thanks!

JD

[Michael G.]

Re: Loud Whining from (cold) Tach

My pic was from a much later car than yours, but the colors are correct and original. Here's a side view.

Mike