Tach Cable Failure
Thread Starter
Pro
Joined: Jul 2013
Posts: 587
Likes: 351
From: Plymouth MA
C2 of the Year Finalist - Unmodified 2020
Tach Cable Failure
My tach cable failed after 1,000 miles.
The tach had been professionally rebuilt by Instrument Specialties of R.I.
Cable is grey in color, believe it came from Zip.
Who offers the most accurate length tach cable, as I believe the failed one may have been a bit too long, resulting in stress?
As usual, thanks for your thoughts...
The tach had been professionally rebuilt by Instrument Specialties of R.I.
Cable is grey in color, believe it came from Zip.
Who offers the most accurate length tach cable, as I believe the failed one may have been a bit too long, resulting in stress?
As usual, thanks for your thoughts...
Melting Slicks
Joined: May 2001
Posts: 2,749
Likes: 776
From: Dadeville AL
I can't help with your question, but FWIW, way back when I had a cable driven tach, cable failure was a routine occurance for me. Maybe not 1,000 miles, but 10,000 miles. But then, maybe mine wasn't set up right.
Safety Car
Joined: Jan 2004
Posts: 4,270
Likes: 561
From: Macedonia Ohio
I had the same issue when I had a cable drive tach. You are absolutely right, if the cable is to long it will fail. I would check with Long Island Corvette and specifically ask them if it is the same length as the original.
Le Mans Master
Joined: Feb 2008
Posts: 5,214
Likes: 447
From: NJ Hockey beer league
I had one of those gray cables (from another source) a while back that right out of the box turned very tightly and the tip was too long. I had to remove the core and rework the casing ends and shorten the tip to get good smooth resistance free operation. There was also no detectable lube on it. You don't ever want to run a tight cable, worse than it failing is ruining the bearings in the tach (or speedo). That being said, it's been working fine for over 5 years now. I think all the vendors source their cables from the same place. Maybe a different batch would be better.
Another option if you have a good original casing is to install a new cable core, They are readily available and you end up with the exact length you want.
Another option if you have a good original casing is to install a new cable core, They are readily available and you end up with the exact length you want.
Race Director
Joined: Oct 2005
Posts: 12,468
Likes: 1,548
From: Camp Verde AZ
C1 of Year Finalist (performance mods) 2019
2017 C1 of Year Finalist
I always take the cable out and grease it up well with clear Superlube grease prior to installing it. I once made mix out of dry graphite powder, dry moly powder and superlube grease I put on the speedo cable, which should last forever.
Doug
Doug
Burning Brakes
Joined: Mar 2012
Posts: 987
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From: Kingwood Texas
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Brett Foote
Intermediate
Joined: Nov 2005
Posts: 45
Likes: 7
I use Deluxe professionally and send all my gauges and cables to them. He won't warranty gauge work without looking at the cable because of the fitment issues. The tach cables will last a very long time if they are correct.
Thread Starter
Pro
Joined: Jul 2013
Posts: 587
Likes: 351
From: Plymouth MA
C2 of the Year Finalist - Unmodified 2020
Appreciate the advice received.
Am awaiting response from Deluxe Speedo, and am strongly considering the 90 degree cable adapter.
Whatever choice I make, I will most certainly lube the cable before installation.
Of course, won't get to it until my recently replaced right knee allows me to do so.
Am awaiting response from Deluxe Speedo, and am strongly considering the 90 degree cable adapter.
Whatever choice I make, I will most certainly lube the cable before installation.
Of course, won't get to it until my recently replaced right knee allows me to do so.
Safety Car
Joined: Aug 2006
Posts: 3,881
Likes: 1,283
From: Horsham Pa
C2 of Year Finalist (appearance mods) 2019
63 and 64 are longer then 65 to 67. If the cable is not run in the proper location and the distributor is not in the proper location it will fail prematurely.
Race Director
Joined: May 2000
Posts: 12,712
Likes: 2,270
… could be an improperly assembled and/or installed distributor. If the wires are indexed properly on the cap, the distributor assembled and installed correctly, and the initial timing is in the proper range, the window should be very close to perpendicular to engine centerline, and the VAC about halfway between the manifold and coil bracket interference points
If not something is screwed up, and it will be nothing but trouble until the improper installation issues are corrected, like too great an angle on the tach cable and the VAC hitting the manifold or coil bracket.
Duke
If not something is screwed up, and it will be nothing but trouble until the improper installation issues are corrected, like too great an angle on the tach cable and the VAC hitting the manifold or coil bracket.
Duke
Instructor
Joined: Mar 2010
Posts: 119
Likes: 53
From: Media, Delaware County, Penna (Next door to Philly)
Ive been following this thread.. Does Deluxe speedo sell just the inner cable for both the tach AND speedo??
I have original housings in my 66 Coupe. Speed o is not working nor is the tach.
Going to pull the cable from the trans end and check that first.. Can the inner speedo cable be pulled from the housing at the trans end and a new one installed or does it have to come from the head side???
I have original housings in my 66 Coupe. Speed o is not working nor is the tach.
Going to pull the cable from the trans end and check that first.. Can the inner speedo cable be pulled from the housing at the trans end and a new one installed or does it have to come from the head side???
Le Mans Master
Joined: Feb 2008
Posts: 5,214
Likes: 447
From: NJ Hockey beer league
Ive been following this thread.. Does Deluxe speedo sell just the inner cable for both the tach AND speedo??
I have original housings in my 66 Coupe. Speed o is not working nor is the tach.
Going to pull the cable from the trans end and check that first.. Can the inner speedo cable be pulled from the housing at the trans end and a new one installed or does it have to come from the head side???
I have original housings in my 66 Coupe. Speed o is not working nor is the tach.
Going to pull the cable from the trans end and check that first.. Can the inner speedo cable be pulled from the housing at the trans end and a new one installed or does it have to come from the head side???
Race Director
Joined: Apr 1999
Posts: 10,866
Likes: 717
From: Beverly Hills/Pine Ridge Florida
Intermediate
Joined: Nov 2005
Posts: 45
Likes: 7
Ive been following this thread.. Does Deluxe speedo sell just the inner cable for both the tach AND speedo??
I have original housings in my 66 Coupe. Speed o is not working nor is the tach.
Going to pull the cable from the trans end and check that first.. Can the inner speedo cable be pulled from the housing at the trans end and a new one installed or does it have to come from the head side???
I have original housings in my 66 Coupe. Speed o is not working nor is the tach.
Going to pull the cable from the trans end and check that first.. Can the inner speedo cable be pulled from the housing at the trans end and a new one installed or does it have to come from the head side???
Last edited by jason_marshall1; Jan 15, 2020 at 03:30 PM.