dismantling 73 tachometer

[2Forty]

The tach in my 73 was dead. Found another 3 wire tach but the housing has a bracket spot welded to it. My old one has 2 studs on the back and was held in place with wing nuts. I want to remove the guts and swap housings. I removed all the nuts and screws and it won't come apart. I haven't applied brute strength yet for fear of breaking something. Anyone take a tach apart?

[beermanpete]

Yes. I have had mine apart. There are 3 (4?) small screws around the perimeter of the black plastic housing that hold the front and rear halves together. These install radially, near the intersection of the plastic and metal parts. Remove these screws and the front will (should) come off leaving the tach in the rear housing. I do not recall needing to use any significant force to separate the two halves.

[2Forty]

I have the black hood off. I need to get the tach out of the metal housing.

[EScanlon]

Look at the wiring connection screws.

IIRC they hold the exterior connections to the interior chassis.

E

[tlorber]

You might want to look into having the guts replaced with new electronics. I wasn't crazy about dropping $170.00 into it, but the new parts are much more accurate, there is no needle bouncing, and they accept wave form signals from all different forms of ignition/distributors.

Prior to having mine rebuilt I had opened it up to verify functionality of all the resistors (13 or so IIRC) and still couldn't get it accurate. Since tach temp and oil are the most crucial gauges to preserving the motor it is money well spent.

Edited February 4, 2012 by tlorber

[2Forty]

Where did you send it for the rebuild?

[beermanpete]

I have the black hood off. I need to get the tach out of the metal housing.

Make sure to remove the terminal block for the wiring. Also, there is a foam piece between the housing and the electronics. It will require a bit of force to break the bond between the foam and the hard parts.

[tlorber]

http://www.nhspeedometer.com/