Tachometer bounces, erratic

[CidTito]

1969 - My tachometer bounces and is very erratic when running between 1K-4K...but reading other posts it seems electrical? The thing is that I have very fresh alternator and voltage regulator. Does it do any good to pull the tachometer out and grease it? If so.. what kind of grease, and exactly where do I want to grease? Is there other troubleshoot I should consider?

Thanks in advanced.

[uai]

I'd try the tach adapt thing.
http://www.ashlocktech.com/TACH-ADAPT.html

[304065]

The bouncing of the tachometer is most likely related to one of the following:

1) Excessive charging voltage. What alternator and regulator? What is battery voltage with engine running? Does not matter if they are new.

2) Defective "intermediate unit" - silver can on electrical console that says "einbau senkrecht klemmen unten"- this shapes the voltage pulse into something the tach can accept; or

3) Bad capacitors in tach. Without the long explanation (search here for "multivibrator" if you want my long version) the length of time the capacitor charges determines for how long current is sent to the meter movement to push the needle higher. If the capacitor is worn out, it won't hold a charge so the needle bounces. Could be a shorted resistor charging the cap also.

It's not grease-- the meter movement is a delicate mechanism of a needle suspended in a cage with a hairspring to pull it down. Not only will you bugger the bezel edge opening the tach, greasing it will make it read low-- if it needs service send it to North Hollwyood Speedometer and they will make it PERFECT.

Good luck!

[CidTito]

ahh.. fantastic reply.. thank you all!!! yes.. its likely the 3.2 and the old tach.

[CidTito]

ahh yes.. so I swapped out the old tach with a newer tach that matches the engine.. poof the problem is gone. I am thinking of rebuild that new tach to look period correct.

So while I am in there and have access to it... Is it then just the Speedometer that gets greasing? If so.. which kind? where?

Again.. thanks in advanced.

[CidTito]

Haha seems funny.. I can understand that... so I think one lubricates the Speedo, and not the Tach. So.. I am only verifying for a procedure... if there is one. just asking.