[C2] Tachometer bouncing

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Apr 20, 2022 | 09:18 PM

mikes1966

Thread Starter

Racer

Joined: Feb 2020

Posts: 271

Likes: 76

From: long island NY

Tachometer bouncing

On my 66 l 72 the tac was bouncing .I changed the cross gear and cable and it still bounces . any ideas ?
thanks mike

Apr 20, 2022 | 09:34 PM

Avispa

Safety Car

Joined: Mar 2009

Posts: 4,191

Likes: 951

From: Corpus Christi, TX

Probably time to pull the tach and give the gauge mechanism a good cleaning, or send it out for a rebuild. They get bouncy when worn and dirty.

Apr 20, 2022 | 10:19 PM

jim lockwood

Race Director

Joined: Feb 2007

Posts: 15,415

Likes: 8,864

From: northern california

C2 of Year Finalist (track prepared) 2019

I vote for rebuilding/replacing the tach mechanism. Every single time I've had a bouncing tach or speedometer, the mechanism itself was simply worn out.

Apr 20, 2022 | 10:25 PM

LouieM

Race Director

Joined: Mar 2002

Posts: 13,633

Likes: 3,579

From: NorCal

At times in the past I've cured a bouncing tach needle by lubing it with Kable-Ease.

Apr 21, 2022 | 08:22 PM

mikes1966

Thread Starter

Racer

Joined: Feb 2020

Posts: 271

Likes: 76

From: long island NY

Ok thanks I look into getting it rebuilt

Apr 21, 2022 | 09:07 PM

joewill

Safety Car

Joined: Sep 2007

Posts: 4,458

Likes: 331

From: Indy Indiana

lube the cable, make sure there are no tight 90 degree turns in the cable housing that might be binding
check the tach gear in the distributor.
.
if this doesn't work then yes, rebuild tach..

Apr 21, 2022 | 09:45 PM

lutronjim

Heel & Toe

Joined: Sep 2016

Posts: 17

Likes: 2

From: Dunwoody Georgia

Might want to remove inter drive cable - let it hang in a U and twist ends between thumb and finger. Some times a cable like this can take a 'set' - if it has you will feel it.

Apr 21, 2022 | 10:05 PM

barkingrats

1967 Pedal Car Champion

Joined: Mar 2020

Posts: 9,062

Likes: 4,196

From: US-PNW

Too much lube traveling down the cable and into the tach head can cause bouncing too. Only remedy is to pull the unit and clean out the excess.

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Apr 21, 2022 | 11:50 PM

ghostrider20

Le Mans Master

Joined: Jan 2002

Posts: 8,913

Likes: 283

There is suppose to be thrust washer on the drive shaft of the gear, and a spec in the service manual for play. If this thrust washer is missing, or too much clearance, the gear will walk in and out as the distributor accelerates and decelerates.

Time to pull the dist. and do an inspection and lubrication.

Last edited by ghostrider20; Apr 22, 2022 at 05:06 PM.