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Jakes-66-K10 · 11-10-2005, 02:12 PM

*UPDATE* My truck has been in the shop for rear shock mount issues, now that I have it back I took it in today to have the tach tested for accuracy. Here is what they found:

At 1000 RPM Reading on Tach: 780 Actual
At 2000 RPM Reading on Tach: 1340 Actual
At 3000 RPM Reading on Tach: 1860 Actual
At 4700 RPM Reading on Tach: 3000 Actual

So this is a step towards solving my issue. Problem now is how to fix it... I remember seeing a hole in the back of the tachometer which seems to be where you can put a philips screwdriver in to help calibrate the tach. Has anyone ever done this though?

Since my RPMs are only 200 near idle, but nearly 1700 rpms off at high speed I'm wondering if the adjustment screw will even be able to help. What would cause a tach to be off like this? It really sucks because I bought it for a hefty price all nicely restored in a complete cluster from a board member.

11-10-2005, 02:12 PM	#24
Jakes-66-K10 Registered User Join Date: Aug 2004 Location: Idaho Posts: 640	Re: My motor RPMs don't seem right UPDATE My truck has been in the shop for rear shock mount issues, now that I have it back I took it in today to have the tach tested for accuracy. Here is what they found: At 1000 RPM Reading on Tach: 780 Actual At 2000 RPM Reading on Tach: 1340 Actual At 3000 RPM Reading on Tach: 1860 Actual At 4700 RPM Reading on Tach: 3000 Actual So this is a step towards solving my issue. Problem now is how to fix it... I remember seeing a hole in the back of the tachometer which seems to be where you can put a philips screwdriver in to help calibrate the tach. Has anyone ever done this though? Since my RPMs are only 200 near idle, but nearly 1700 rpms off at high speed I'm wondering if the adjustment screw will even be able to help. What would cause a tach to be off like this? It really sucks because I bought it for a hefty price all nicely restored in a complete cluster from a board member.