good morning,

I have to replace the pointer tach in my instrument.



can any of you kindly tell me how to open the gauge to reach and replace the pointer?
thank you in advance

 

The hardest part is getting it out of the car. Plenty of threads on how to remove left dash assembly.
some pull the column, some just lower it. Once you have the left dash assembly out, disassembly of the tach is pretty straight forward.

 

yes, my english's fault :-)

my question is about how to remove left dash. ok, i will looking for old discussion

 

To prevent breaking/cracking the left dash pad, you really need to remove the steering column. This is no small task, but it is the only way to access the rear of that dash to remove the screws holding the tach in place. And, you need to remove the tach to access the needle. Easy to change the needle...BUT you have to make sure that you put it back at the correct location. The BEST way to do that (IMO) is to use a battery operated hand drill on LOW SPEED setting to drive the tach and read the rpm's at that speed. THEN remove that broken needle and loosely install (without locking it down) the new needle. Now use the drill again to obtain that same rpm. If the needle is off-position, just push it to the right place while the tach is being driven by the drill. When it reads correctly, turn off the drill and push the needle down to lock it in position.

P.S. If you know what speed your portable drill runs on LOW SPEED setting, you can calculate EXACTLY what the tach should read at that input speed. If your tach was in error prior to your repair, NOW is the time to set it properly. It would be best to check the accuracy somewhere around 2000-2500 rpm AND at 3500-4000 rpm on the dial. If you want the best accuracy at the high end of the rpm scale, just set it precisely at that high rpm setting (5500-6000) and let the accuracy below that rpm fall where it may. You have options on how you position that needle based on how you intend to use that tachometer.

 

thank you for your detailed reply.

in your opinion, do you thing is better change the entire instrument?
or the tuning after installation of the new pointer installation is easy?

 

If the tach has never given you any problems, I would just put a new needle on it and calibrate it (as you need). Sometimes, new replacements can cause more problems than a well-functioning 'old' one.

 

ok, thank you