[tony maddox]

i just bought a used tach from another member here it works but it dont go to zero . when the key is on and engine not running the needle is on 2000 . with engine running it shows it idleing around 3000 but engine is only idleing around 800 to 1000 rpms is there anyway to adjust them or anything i can do without replaceing it. thanks, tony

["QUICK-SILVER"]

Without thinking I pulled the needle off a tach one time without indexing the movement on the back. Was doing a repaint for a dash light color change. Needless to say I saw it was going to be off when it came time to put it back on. I ended up hooking up a second tach, then sticking the original back on in sync with the added tach. It worked good, both tachs read the same from idle to shift point.

This tach did read right, it just would've been off some number of RPM's. So if yours is off but working right you might want to give it a try. The tach had to be stripped so you could support the movement while pushing the needle on tight. They've got some pretty fragile small parts.

If your needles NOT moving right with RPM's, this wont help.
So I guess that makes this one of them FWIW's

George K recently walked a guy through a near complete rebuild on a tach. So if this tach is a 'keeper' you might want to shoot him a PM.

[tony maddox]

thanks for reply but on my 74 ta tach it doesent look like the needle comes off. looks like the needle is part of the stem that goes inside the tach. it seems to work right its just off 2000 rpms. anyone have any ideas or know anyone that can fix it . thanks tony

[Peter Serio]

The meter is bad, it cannot be repaired. Those did not have a traditional zero, like a normal tach would have, say in a GTO. Zero for a trans am tach is more like 4:30-5PM on a clock dial. The springs that balance the meter get weak, bent, broken and/or stretched out over time. They are non removable as they are both soldered and wound in when the meter is made. The only cure is to get another tach or find an NOS meter assembly. Those trans am tachs are very old and they go bad all the time, if one gets dropped, or shaken (out of the car) even that can ruin the meter!