Tach problem!!!
Thread Starter
Burning Brakes
Joined: Jun 2007
Posts: 945
Likes: 8
From: Miami FL
Tach problem!!!
Okay, here I am now having put my dash back together and my tach started making little tick-tick-tick and then squealing noises. Got under the dash and saw the cable was loose attaching to the back of the tach. No problem. Not easy to tighten all assembled but I did my best. Lasted for about a week. Noise starts to come back. Again I get under the dash and I was able to use some long bent nose pliers and gave it a bit of a turn. All good.
Today I driving and the tach dies. It goes to zero and that’s all she wrote.
I decide to look at the cable attached to the distributor and I’m surprised to see the black casing has almost separated from the chrome part attaching to the distributor (I even see some wire frays from the cable). I attempted to remove it from the distributor and that sucker is stuck tight. Came out after a lot of coaching. The cable is all frayed as if the tach side stop and the distributor side continued to spin for a while.
Tomorrow I’ll try to get under the dash to disconnect the cable from the tach and see what I’ve got.
What’s going on here???
Oh.. Of course I had replaced perfectly good cables for the Tach and speedo when I did all the work. Seemed like a good idea at the time.
Joe
Today I driving and the tach dies. It goes to zero and that’s all she wrote.
I decide to look at the cable attached to the distributor and I’m surprised to see the black casing has almost separated from the chrome part attaching to the distributor (I even see some wire frays from the cable). I attempted to remove it from the distributor and that sucker is stuck tight. Came out after a lot of coaching. The cable is all frayed as if the tach side stop and the distributor side continued to spin for a while.
Tomorrow I’ll try to get under the dash to disconnect the cable from the tach and see what I’ve got.
What’s going on here???
Oh.. Of course I had replaced perfectly good cables for the Tach and speedo when I did all the work. Seemed like a good idea at the time.
Joe
Tech Contributor
Joined: May 2005
Posts: 15,576
Likes: 118
From: Conroe Texas
Thread Starter
Burning Brakes
Joined: Jun 2007
Posts: 945
Likes: 8
From: Miami FL
The cable to the dist is a slight curve (very little). I left the excess cable neatly tucked under the dash. ...maybe that's my problem.
...good question.
I had hand tightened the cables to the back of the cluster but maybe it wasn't enough.
...good question.
I had hand tightened the cables to the back of the cluster but maybe it wasn't enough.
Thread Starter
Burning Brakes
Joined: Jun 2007
Posts: 945
Likes: 8
From: Miami FL
Thanks Jeff. I do remember the new cable being a bit longer than the old one. Didn't think much of it at the time...... Hmmmmm
It's late and I don't want to think about what I have to do to replace the d@mn cable.....
Joe
It's late and I don't want to think about what I have to do to replace the d@mn cable.....
Joe
Tech Contributor
Joined: May 2005
Posts: 15,576
Likes: 118
From: Conroe Texas
I mis-spoke, I meant to say I could imagine it getting twisted up at the distributor (not the tach).
In any event, think about the cable path when you replace it, in case that was the root cause.
In any event, think about the cable path when you replace it, in case that was the root cause.
Thread Starter
Burning Brakes
Joined: Jun 2007
Posts: 945
Likes: 8
From: Miami FL
I'm typing with one hand since my right arm still doesn't have any feeling... I replaced my tach cable without pulling the cluster, just did it in place.
Used a pair of long, bent needle nose pliers. I don't want to do this again any time soon but it was definitely worth it. Tach is working again. The first cable I installed I was a little too 'creative' with the way I routed it. Worked for less than two weeks then seized up. All is good!!
Thanks for the help Jeff…
Joe
Used a pair of long, bent needle nose pliers. I don't want to do this again any time soon but it was definitely worth it. Tach is working again. The first cable I installed I was a little too 'creative' with the way I routed it. Worked for less than two weeks then seized up. All is good!!Thanks for the help Jeff…
Joe
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Thread Starter
Burning Brakes
Joined: Jun 2007
Posts: 945
Likes: 8
From: Miami FL
The cable came from Paragon (I thought they would have the right parts). It's a 27" long cable but it is longer than the one I threw away (so I don't know the length of what I had). I did have to do a bit of an 'S' bend at the dist. I do see a bounce at < 1500 RPM. We'll see. Last time it lasted <2 weeks. so far so good.
Where did you get the correct cable?
(so I don't know the length of what I had). I did have to do a bit of an 'S' bend at the dist. I do see a bounce at < 1500 RPM. We'll see. Last time it lasted <2 weeks. so far so good.Where did you get the correct cable?
Le Mans Master
Joined: Jan 2002
Posts: 8,913
Likes: 283
Is the drive cable plastic? I was sent a new tach cable and the drive cable was plastic. It was horrible, bounced all over. I was going to use it until I got my original cable restored. Just went without for a week or two until my original was good to go.
Mark
Mark
Thread Starter
Burning Brakes
Joined: Jun 2007
Posts: 945
Likes: 8
From: Miami FL
Its nice. The cable is steel and the casing is black and looks well made. It just may be a bit too long. Now, I do have a Mallory dist. The connection is on the left, front side and its aimed almost towards the cable firewall hole. I had to snake the cable towards the wiper/washer and back to the dist. Is the cable connection for my Mallory different than stock?
Le Mans Master
Joined: Mar 1999
Posts: 5,401
Likes: 986
From: Itasca IL
The 27" cable from Paragon does seem excessively long, but it works well in my car. The cable from ZIP is quite a bit shorter, and i elected not to use it. The added length allows some flexiblity in the routing, make sure it has no sharp bends and curves smoothly all the way.
Former Vendor
Joined: Aug 2006
Posts: 76,656
Likes: 1,853
From: Jeffersonville Indiana 812-288-7103
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15
Joe,
The original cable was GM p/n 3866126; this cable was 24 1/8" long. It was replaced sometime around 68 (I can’t read my notes on this) with part number 6476986 which also carried the exact same measurements. 6478117 was the next number then followed by 6470367 which was made to accommodate both the mid year cars as well as the 1968 (which had a screw on cable like the mid years). Next new number for this cable was 88959456 which was listed at 24.61 in length.
So there you have some cable history! We carry the 88959456 cable it’s not on our web site and higher than the reproduction cable. It is a workable GM replacement of the original cable and you may be able to find this cable at a local parts house if you check.
Now this is a bit of an irony here: for years we sold and installed the 6470367 cable and it worked fine. However, from time to time we would have people call us and tell us the cable was to short. I’m not really sure the cable was short but it was a close tight fit. I have installed the old 6470367 repeated times with no problems. I could only assume the 88959456 would do just fine except for the look.
Another product that is not factory that you may want to consider is the 90 degree adapter. http://willcoxcorvette.com/product_i...ducts_id=24713
Good luck,
Willcox
The original cable was GM p/n 3866126; this cable was 24 1/8" long. It was replaced sometime around 68 (I can’t read my notes on this) with part number 6476986 which also carried the exact same measurements. 6478117 was the next number then followed by 6470367 which was made to accommodate both the mid year cars as well as the 1968 (which had a screw on cable like the mid years). Next new number for this cable was 88959456 which was listed at 24.61 in length.
So there you have some cable history! We carry the 88959456 cable it’s not on our web site and higher than the reproduction cable. It is a workable GM replacement of the original cable and you may be able to find this cable at a local parts house if you check.
Now this is a bit of an irony here: for years we sold and installed the 6470367 cable and it worked fine. However, from time to time we would have people call us and tell us the cable was to short. I’m not really sure the cable was short but it was a close tight fit. I have installed the old 6470367 repeated times with no problems. I could only assume the 88959456 would do just fine except for the look.
Another product that is not factory that you may want to consider is the 90 degree adapter. http://willcoxcorvette.com/product_i...ducts_id=24713
Good luck,
Willcox
Melting Slicks
Joined: Oct 2001
Posts: 2,740
Likes: 4
From: Marblehead MA
A little trick to help ease the installation of either the tach or speedometer cable is to go to the hardware store and get two 1/4 x 20 by 8 to 10 in long bolts. Take the screws out of each end of the dash and install the 'long ones' in their place. Next take out the rest of the screws. Once you have done that your dash will now 'slide out' enough to get your paws up behind the dash and get a good grip on those cable ends...
