Another tach failure! Arrrrg!
Thread Starter
Drifting
Joined: May 2002
Posts: 1,546
Likes: 282
From: Back in Nebraska
Another tach failure! Arrrrg!
I am tired of replacing mechanical tachometer parts on my 1970. Thinking of getting an electronic tach from a 1975 or 1976 and installing it in place of my original. Has anyone else done this? What do I need besides the tach to make it work? 
Race Director
Joined: Dec 1999
Posts: 19,610
Likes: 778
From: Forked River NJ
I just had this done. A forum member here did it for 135. Used my old tach face with all new guts. He sent me a picture of it all done and it looks great. It will be back in my hands Tuesday or Wednesday. I got tired of the bouncy cable driven tach. Took about 2 weeks total from the time I shipped it out until he sent it back.
Race Director
Joined: Dec 1999
Posts: 19,610
Likes: 778
From: Forked River NJ
I would think so but I can't say for sure. The face should be the same size so that would not be an issue.The speedo will look different as the numbers are slightly different from 70 to 75
Racer
Joined: Jul 2005
Posts: 499
Likes: 1
From: Winnipeg Manitoba
Race Director
Joined: Dec 1999
Posts: 19,610
Likes: 778
From: Forked River NJ
I have a Crane HI6 box on mine and it definitly says not to use the tach filter. I talked to Crane about this and they confirmed this. Iwill not be running a tach filter on mine. I think they are about 15 bucks for the filter. If you are running a MSD or Crane box a filter is not needed. I don't worry about radio noise as the pipes and engine make more noise than my radio will ever put out. 
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Drifting
Joined: Dec 2004
Posts: 1,345
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I have had only ONE series of failures on the mechanical tach on my '69 over 145,000 miles and 31 years of driving.
The problem was the driving gear on the distributor shaft was worn causing the driven gear to wear out quickly. Once that was discovered, the tach has worked without interruptions over the past 120,000 miles.
Do you really drive that much more that you are seeing problems?
The problem was the driving gear on the distributor shaft was worn causing the driven gear to wear out quickly. Once that was discovered, the tach has worked without interruptions over the past 120,000 miles.
Do you really drive that much more that you are seeing problems?
Thread Starter
Drifting
Joined: May 2002
Posts: 1,546
Likes: 282
From: Back in Nebraska
No, I don't drive that much at all. I am not really sure why I keep having failures. I have had to replace the cable twice and the worm gear once. I just thought that by putting in an electronic tach I could just drive and forget the tach. As it is now, every time I drive I'm watching and listening for a failure. I plan on saving all of my original equipment in case I sell the car.
Race Director
Joined: Dec 1999
Posts: 19,610
Likes: 778
From: Forked River NJ
I have had only ONE series of failures on the mechanical tach on my '69 over 145,000 miles and 31 years of driving.
The problem was the driving gear on the distributor shaft was worn causing the driven gear to wear out quickly. Once that was discovered, the tach has worked without interruptions over the past 120,000 miles.
Do you really drive that much more that you are seeing problems?
The problem was the driving gear on the distributor shaft was worn causing the driven gear to wear out quickly. Once that was discovered, the tach has worked without interruptions over the past 120,000 miles.
Do you really drive that much more that you are seeing problems?
My biggest problem was the way the tach bounces up and down when the rpm climbs real fast. I have all new components in mine and it works fine on normal driving. When you jump on it and start going through the gears fast it moves around quite a bit. This is why I have a shift light. To try and determine 6500 rpm while it is bouncing around is almost impossible. Plus with the shift light you don't have to look down. Just a flash of light and shift. For normal driving the tach drive is fine.
Team Owner
Joined: Apr 2001
Posts: 54,204
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From: S.W. Ohio. . . . . . NRA Life Member
yes, a 1975 thru 1977 tach assembly will bolt right in place of your earlier mechanical tach.
Although, the dial face and pointer probably won't be perfect matches with your speedometer dial (and their may be differences in the way both have faded).
If you want a totally stealthy conversion that uses your existing dial face and pointer, I do this type of conversion. Email me for more information:
tim-yvonne@juno.com
Although, the dial face and pointer probably won't be perfect matches with your speedometer dial (and their may be differences in the way both have faded).
If you want a totally stealthy conversion that uses your existing dial face and pointer, I do this type of conversion. Email me for more information:
tim-yvonne@juno.com
