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> Tachometer Replacement, Any aftermarket tachs out there?
SteveNMaine
post Aug 19 2025, 12:55 PM
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My original tach did not work so I swapped it out with the parts car tach, it worked for a few days and it died. Did my 123Ignition kill my tach?

Are there any aftermarket 4.5in / 144mm replacements out there that don't cost $500?
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T.Rick6
post Aug 19 2025, 03:23 PM
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I’d get in touch with John Bell and have your original looked at, he’s reasonable and does a fantastic job. (IMG:style_emoticons/default/beerchug.gif)

Todd
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GregAmy
post Aug 19 2025, 05:22 PM
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https://speedhut.com/gauge-applications/rev...pm-shift-light/

3D printed a thin 1/4" wider plastic washer to put between the tach and the stock rubber grommet to capture it to the correct size so it would not fall in.

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76-914
post Aug 19 2025, 07:29 PM
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QUOTE(GregAmy @ Aug 19 2025, 04:22 PM) *

https://speedhut.com/gauge-applications/rev...pm-shift-light/

3D printed a thin 1/4" wider plastic washer to put between the tach and the stock rubber grommet to capture it to the correct size so it would not fall in.

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I'll 2nd that! Good people and they'll work with you.
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digit3
post Aug 22 2025, 07:31 AM
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QUOTE(T.Rick6 @ Aug 19 2025, 04:23 PM) *

I’d get in touch with John Bell and have your original looked at, he’s reasonable and does a fantastic job. (IMG:style_emoticons/default/beerchug.gif)

Todd


+1

John does nice work and is pleasant to do business with.
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SteveNMaine
post Aug 22 2025, 08:03 AM
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How do I reach John Bell?
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rick 918-S
post Aug 23 2025, 11:23 AM
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T.Rick6
post Aug 23 2025, 12:55 PM
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Jbellshome@yahoo.com
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porschetub
post Aug 23 2025, 05:26 PM
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If you are good @ DIY and can open the gauge up you can fit an upgraded (modern ) replacement driver board for these tachs from Ashlocktech , not expensive and I had one fitted to my 73 911 tach and they work fantastic ,even when this tach worked previously it was never as good as with upgrade driver board.
Payed a specialist guy locally in my country to fit the board and test operation..best 75nzd I ever spent .
Used ones aren't a reliable option IMO as I found out (IMG:style_emoticons/default/sad.gif) .
Cheers.

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Dave_Darling
post Aug 23 2025, 05:40 PM
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A popular option used to be one of the tachs from "Monster Tach". You will want to measure the hole in the panel and the hole in the grommet to be sure, but one of them allegedly fit without mods.

Sorry, I don't remember which one. I never really liked the look so the model didn't stick in my head.

--DD
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MAD914
post Aug 25 2025, 01:03 PM
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QUOTE(SteveNMaine @ Aug 19 2025, 11:55 AM) *

My original tach did not work so I swapped it out with the parts car tach, it worked for a few days and it died. Did my 123Ignition kill my tach?

Are there any aftermarket 4.5in / 144mm replacements out there that don't cost $500?


The "Datsun Z" tachs at Speed Hut are 4.5 inches - I'm looking into them too.
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MAD914
post Aug 26 2025, 05:32 PM
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QUOTE(SteveNMaine @ Aug 19 2025, 11:55 AM) *

My original tach did not work so I swapped it out with the parts car tach, it worked for a few days and it died. Did my 123Ignition kill my tach?

Are there any aftermarket 4.5in / 144mm replacements out there that don't cost $500?



@SteveNMaine

UPDATE: I called Speedhut. The woman I spoke to did not know who John Bell was. However, she directed me to the "Gauge Application" tab of their website, where they have a 4.5" "drop-in" Porsche tach replacement for $226. For another $30, they'll add turn signal and high-beam indicators to the gauge face. You'll need the adapter rings too, I think.
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robkammer
post Aug 28 2025, 02:00 PM
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Sort of on the subject, my tach was acting up t a vintage event last Fall and then quit. Turns out the connector at the coil was failing and then failed completely. Easy fix but ever since the tach has been wonky at low rpm's and idle. Is that wire the only signal source for the tach? And could the weak signal from the coil as the connector was failing caused some damage? All connections on the tach are solid.
Robbo
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robkammer
post Aug 28 2025, 02:00 PM
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Sort of on the subject, my tach was acting up t a vintage event last Fall and then quit. Turns out the connector at the coil was failing and then failed completely. Easy fix but ever since the tach has been wonky at low rpm's and idle. Is that wire the only signal source for the tach? And could the weak signal from the coil as the connector was failing caused some damage? All connections on the tach are solid.
Robbo
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Dave_Darling
post Aug 29 2025, 01:06 AM
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The black/purple wire is the only source of RPM information for the tach.

It is unlikely that a bad connection would kill the internals of the stock tach, but with old electronics, who knows?

--DD
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VaccaRabite
post Aug 29 2025, 06:28 AM
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QUOTE(Dave_Darling @ Aug 29 2025, 03:06 AM) *

The black/purple wire is the only source of RPM information for the tach.

It is unlikely that a bad connection would kill the internals of the stock tach, but with old electronics, who knows?

--DD


Also, if the purple and black tach wire grounds out, not only will it kill the tach, but it will also kill the engine.

If the engine runs after the tach fails, its probably not a bad wire.

Zach
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SteveNMaine
post Sep 12 2025, 09:03 AM
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QUOTE(porschetub @ Aug 23 2025, 05:26 PM) *

If you are good @ DIY and can open the gauge up you can fit an upgraded (modern ) replacement driver board for these tachs from Ashlocktech , not expensive and I had one fitted to my 73 911 tach and they work fantastic ,even when this tach worked previously it was never as good as with upgrade driver board.
Payed a specialist guy locally in my country to fit the board and test operation..best 75nzd I ever spent .
Used ones aren't a reliable option IMO as I found out (IMG:style_emoticons/default/sad.gif) .
Cheers.

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Are there any instructions anywhere? I see you removed the original circuit board. How do you take the needle off to remove the works from the face of the gauge?
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Cairo94507
post Sep 12 2025, 09:12 AM
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I second John Bell; great guy who does great work. (IMG:style_emoticons/default/beerchug.gif)
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SteveNMaine
post Sep 12 2025, 11:38 AM
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QUOTE(SteveNMaine @ Sep 12 2025, 09:03 AM) *

QUOTE(porschetub @ Aug 23 2025, 05:26 PM) *

If you are good @ DIY and can open the gauge up you can fit an upgraded (modern ) replacement driver board for these tachs from Ashlocktech , not expensive and I had one fitted to my 73 911 tach and they work fantastic ,even when this tach worked previously it was never as good as with upgrade driver board.
Payed a specialist guy locally in my country to fit the board and test operation..best 75nzd I ever spent .
Used ones aren't a reliable option IMO as I found out (IMG:style_emoticons/default/sad.gif) .
Cheers.

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Are there any instructions anywhere? I see you removed the original circuit board. How do you take the needle off to remove the works from the face of the gauge?

What gauge wire is used to connect circuit board to chip?
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