Topic: Distributor Tach Gear
in Forum: C3 Engines
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Hi, back again. I am having a problem with the tach needle jumping.
took out the tach gear and there is only one piece, the gear itself.
So I look to purchase a new gear and see a washer in addition to a button.
when you pull the old gear out should the button come out also.
Appreciate the help.
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Lifetime MemberModerator
Duncanville, TX - USA
Joined: 11/8/2003
Posts: 20214
Vette(s): #1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/
Am-Fm/map light National/Regional/Chapter NCRS "Top Flight"
#2-1985 Bright Red/Carmine Cp.L-98/auto
Member: NCRS, NCRS Texas, Corvette Legends of Texas
The "button" is a nylon insert that goes in the end of the hole on the distributor, where the drive gear rides. It gives the gear a soft, non-metallic surface to ride against. It rarely wears out, but it wouldn't hurt to replace it since you're already in there. Also, make sure to look at the gear surface of the distributor shaft itself, to see if there is any abnormal wear on it. If the driven gear you are replacing is worn, there is a chance that the shaft gear surface is also worn, tho the driven gear is usually a softer metal.
hth
hth
Joel Adams
C3VR Lifetime Member #56 
My Link 
(click for Texas-sized view!) NCRS
"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"
I only pulled the drive gear out.
I did not take out the distributor as I am just getting the dash back together.
when you take off the cable then the gear coupler and gear that is all that came out.
did something drop inside the distributor?
Lifetime MemberModerator
Duncanville, TX - USA
Joined: 11/8/2003
Posts: 20214
Vette(s): #1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/
Am-Fm/map light National/Regional/Chapter NCRS "Top Flight"
#2-1985 Bright Red/Carmine Cp.L-98/auto
Member: NCRS, NCRS Texas, Corvette Legends of Texas
The "button" I referred to is in the dist housing itself. It should not come out with the gear. If you look at the opposite side of the hole that the gear fits into, you'll see a tiny hole, with a little tab of nylon sticking out....this is the button.
I'm looking for a pic....
Here ya go....# X2557
I'm looking for a pic....
Here ya go....# X2557
Joel Adams
C3VR Lifetime Member #56
My Link
(click for Texas-sized view!) NCRS
"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"
Hello All, I had the same "bounce" of the TACH as well in my '71 Vette and had to take out the distributor shaft and in the housing,where the shaft runs is a bronze bushing to keep the shaft straight.After years of running,the bushing lays a path in the bushing and then the TACH will bounce especially at idle,however will also at elevated RPM's as well..The bushing has to be pressed out and then pressed in,however finding the bushing is also very difficult,hence I did a friends and had him buy just the housing instead of trying to get the bushing.Most of the parts people and Vette drivers knew there was a bushing to wear out.. Hope this help and that is a great diagram that was included in this message.. Take care all...Sal C
Sal and Joel
Joel thanks for that breakdown. I am missing a washer and need to purchase a new gear.
I really do not want to pull the distributor to replace the button.
I am going to try the gear and washer first.
thanks for the help.
I will try that and let you know if it works.
Is keeping the original distributor mandatory? Could switch over to HEI.
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DanT
in Forum: C3 Engines
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