Spongy tachometer
Thread Starter
Melting Slicks
Joined: Nov 2001
Posts: 2,659
Likes: 7
From: Katy (Houston) TX
CI 7-8 Veteran
Spongy tachometer
I haven't had my tachometer working in a very long time and finally got around to replacing it. I replaced the tachometer cable and got one of those 90 degree bend adapters for the distributor. Well now the needle seems very spongy. It bounces around a bit when I rev the motor.
Is this normal or is there something that fixes this?
Is this normal or is there something that fixes this?
Team Owner
Joined: Jul 1999
Posts: 65,492
Likes: 230
From: Orange Park Florida
Re: Spongy tachometer (tshort)
Cable lube is a good easy place to start, a bit of graphite and maybe WD40 to see if that helps...if not...
time to remove dash, ouch, and take tach apart on kitchen table, this is delicate surgery, not a garage thing....
pull pointer off with finger tips, it's hard.....
then remove everything carefully, down to an aluminum C shaped strap with ears and two screws over the casting....carefully remove this piece to get at the final bearing...it's a needle arrangement in front and get dry...
same setup at a speedo....when they start varrying all over the scale, the spinning magnet tight bearing gets the aluminum cup to grabbing....
you can see that when it's apart....
careful of that stove top calrod looking spring, it's super fragile....
GENE
time to remove dash, ouch, and take tach apart on kitchen table, this is delicate surgery, not a garage thing....
pull pointer off with finger tips, it's hard.....
then remove everything carefully, down to an aluminum C shaped strap with ears and two screws over the casting....carefully remove this piece to get at the final bearing...it's a needle arrangement in front and get dry...
same setup at a speedo....when they start varrying all over the scale, the spinning magnet tight bearing gets the aluminum cup to grabbing....
you can see that when it's apart....
careful of that stove top calrod looking spring, it's super fragile....
GENE
Thread Starter
Melting Slicks
Joined: Nov 2001
Posts: 2,659
Likes: 7
From: Katy (Houston) TX
CI 7-8 Veteran
Re: Spongy tachometer (mrvette)
Thanks for advice Gene. I think I'll just try to lube it for now. I just finished putting my dash back in and it's a real bitch. :smash: Don't feel like doing that again. At least not for a while.
Team Owner
Joined: Jul 1999
Posts: 65,492
Likes: 230
From: Orange Park Florida
Re: Spongy tachometer (tshort)
tshort, you too???
snicker....
speedo made me do it twice, I got lazy first time and just did the easy bearing where cable plugs in....
it's allways the tiney small bearing you need take it apart to see...in MY case anyway....
GENE
snicker....
speedo made me do it twice, I got lazy first time and just did the easy bearing where cable plugs in....
it's allways the tiney small bearing you need take it apart to see...in MY case anyway....
GENE
Team Owner
Joined: Jul 2001
Posts: 182,997
Likes: 88
From: Lakeland, FL
Cruise-In IV-V-VI-VII-VIII Veteran
St. Jude Donor '03, '06, '17
Re: Spongy tachometer (tshort)
I hope that the only problem you have is with the cable... Sometimes the transmission on the tachometer gets stuck and can mess up your cable and your tachometer drive gear on the distributor (and even the main shaft...)
You can check if the transmission is stuck very easy. Try to turn the part of the tach where the cable plugs in. It should turn without a lot of resistance. If you feel a lot of resistance you should rebuild your tach before damaging other components.
Olivier
You can check if the transmission is stuck very easy. Try to turn the part of the tach where the cable plugs in. It should turn without a lot of resistance. If you feel a lot of resistance you should rebuild your tach before damaging other components.
Olivier
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