Need help reclocking tach drive distributor
Thread Starter
Intermediate
Joined: Jul 2007
Posts: 40
Likes: 0
From: Brownstown Michigan
Need help reclocking tach drive distributor
I installed a 90% tach cable adapter to my distributor and it worked well for about 100 miles then my tach gauge stopped working. I suspect the tach cable went because my distributor tach thread is pointed so close to the firewall causing the cable to bend. Anyway, I wanted to reclock my distributor so it angles a certain way and hopefully restores the bend on my tach cable. Any suggestions on reclocking my distributor is greatly appreciated. Thanks.
Tony
Tony
Melting Slicks
Joined: Apr 2006
Posts: 2,084
Likes: 14
From: Airdrie Alberta
There was a paper Lars did on Installing Chevy Distributers. Basically on the Corvette to clear the ignition shielding with the vacume advance you shifted the plug wires 1 position to the left.
I fried my tach cable the first time because there was too sharp of an angle on it. Lars saved me
I fried my tach cable the first time because there was too sharp of an angle on it. Lars saved me
Last edited by hwcoop; Sep 12, 2008 at 08:17 AM.
Drifting
Joined: Dec 2007
Posts: 1,634
Likes: 1
From: aurora
Thread Starter
Intermediate
Joined: Jul 2007
Posts: 40
Likes: 0
From: Brownstown Michigan
That is what I have and I believed what caused my problem. When I installed it, it was not sitting properly as it should. In other words, it was very tight mounted to the distributor thread, however the 90% adapter was still wobbling. I'm afraid If I over tighten it to eliminate the wobble, I might break or destroy something.
Drifting
Joined: Dec 2007
Posts: 1,634
Likes: 1
From: aurora
That is what I have and I believed what caused my problem. When I installed it, it was not sitting properly as it should. In other words, it was very tight mounted to the distributor thread, however the 90% adapter was still wobbling. I'm afraid If I over tighten it to eliminate the wobble, I might break or destroy something.
cant help ya sorry
Safety Car
Joined: Oct 2007
Posts: 3,729
Likes: 267
From: Austin Texas
Corvette of the Year Winner 2017
2016 C3 of Year Finalist
Bump the Engine to #1-TDC
Verify and mark Dist. #1 location.
unclamp Dist., pull the dist up carefully both hands until,
the Dist. gear --just becomes disengaged, rotate Dist 1 tooth over.
now drop back down into clamp position.
Repeat until you have rotated Dist. to desired rotation.
Line up #1, put it to together. 69VETT
Verify and mark Dist. #1 location.
unclamp Dist., pull the dist up carefully both hands until,
the Dist. gear --just becomes disengaged, rotate Dist 1 tooth over.
now drop back down into clamp position.
Repeat until you have rotated Dist. to desired rotation.
Line up #1, put it to together. 69VETT
Le Mans Master
Joined: Jun 2008
Posts: 5,284
Likes: 235
From: Rockledge FL
There was a paper Lars did on Installing Chevy Distributers. Basically on the Corvette to clear the ignition shielding with the vacume advance you shifted the plug wires 1 position to the left.
I fried my tach cable the first time because there was too sharp of an angle on it. Lars save me
I fried my tach cable the first time because there was too sharp of an angle on it. Lars save me
i thought that the distributer had been installed wrong.
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Advanced
Joined: Jun 2008
Posts: 67
Likes: 0
Tony,
My experience has been once the outer sheath of the cable has taken a set any changes in anlgle and/or position will cause the cable to chaffe the inner housing of the assembly. With a new cable you should have no issues using the adapter.
Stormin
My experience has been once the outer sheath of the cable has taken a set any changes in anlgle and/or position will cause the cable to chaffe the inner housing of the assembly. With a new cable you should have no issues using the adapter.
Stormin
Melting Slicks
Joined: Mar 2005
Posts: 2,838
Likes: 10
From: Austin TX
Finding TDC for #1 is a start, but you need to find TDC after the compression stroke, not after the exhaust stroke. This requires removing the driver's side valve cover and watching the valves on over the # 1.
Once you've found this TDC, drop the distributor housing in where you want it with the rotor pointing toward the number one terminal of the distributor cap.
For accuracy, attach the # 1 plug wire to an old spark plug. With the igntion on (don't start the car), ground the old plug while you rotate the cap back and forth and you'll see sparks at the plug when you pass over the # 1 terminal on the cap.
(Don't ground the plug near carb for obvious reasons).
Reattach the # 1 plug wire and then car will then start and you can set you timing to specs.
Good luck!
Once you've found this TDC, drop the distributor housing in where you want it with the rotor pointing toward the number one terminal of the distributor cap.
For accuracy, attach the # 1 plug wire to an old spark plug. With the igntion on (don't start the car), ground the old plug while you rotate the cap back and forth and you'll see sparks at the plug when you pass over the # 1 terminal on the cap.
(Don't ground the plug near carb for obvious reasons).
Reattach the # 1 plug wire and then car will then start and you can set you timing to specs.
Good luck!
Thread Starter
Intermediate
Joined: Jul 2007
Posts: 40
Likes: 0
From: Brownstown Michigan
Stormin,
I have a brand new tach cable and tach gauge installed at the same time. I believed the 90% adapter caused the cable to break at high RPM due to excessive wobbling of the adapter. I believed had the adapter were tight and weren't moving, this would not been an issue. Could it be because my distributor is new and the 90% adapter did not screw in far enough? What do you think?
I have a brand new tach cable and tach gauge installed at the same time. I believed the 90% adapter caused the cable to break at high RPM due to excessive wobbling of the adapter. I believed had the adapter were tight and weren't moving, this would not been an issue. Could it be because my distributor is new and the 90% adapter did not screw in far enough? What do you think?
Thread Starter
Intermediate
Joined: Jul 2007
Posts: 40
Likes: 0
From: Brownstown Michigan
Finding TDC for #1 is a start, but you need to find TDC after the compression stroke, not after the exhaust stroke. This requires removing the driver's side valve cover and watching the valves on over the # 1.
Once you've found this TDC, drop the distributor housing in where you want it with the rotor pointing toward the number one terminal of the distributor cap.
For accuracy, attach the # 1 plug wire to an old spark plug. With the igntion on (don't start the car), ground the old plug while you rotate the cap back and forth and you'll see sparks at the plug when you pass over the # 1 terminal on the cap.
(Don't ground the plug near carb for obvious reasons).
Reattach the # 1 plug wire and then car will then start and you can set you timing to specs.
Good luck!
Once you've found this TDC, drop the distributor housing in where you want it with the rotor pointing toward the number one terminal of the distributor cap.
For accuracy, attach the # 1 plug wire to an old spark plug. With the igntion on (don't start the car), ground the old plug while you rotate the cap back and forth and you'll see sparks at the plug when you pass over the # 1 terminal on the cap.
(Don't ground the plug near carb for obvious reasons).
Reattach the # 1 plug wire and then car will then start and you can set you timing to specs.
Good luck!
Drifting
Joined: Dec 2004
Posts: 1,345
Likes: 3
In the end you may find the gear on the distributor shaft is worn causing the mating gear to wear out prematurely.
It is easy to reclock the distributor and you should NEVER need an angle adapter to get the tach cable to exit towards the firewall in a smooth arc.
It is easy to reclock the distributor and you should NEVER need an angle adapter to get the tach cable to exit towards the firewall in a smooth arc.
Drifting
Joined: Apr 2007
Posts: 1,970
Likes: 45
From: Cameron Park CA
There seems to be a lot of confusion about the correct alignment of the distributor in Corvettes. Unlike most Chevrolet products that have the vacuum can pointing sort of toward the right front wheel, ours need to be pointing slightly back, kinda toward the heater motor. Here is the correct alignment per the 1969 AIM.
When you install the distributor per the drawing, the tach cable will line up perfectly and you won't need to put a kink in it or buy one of those crazy 90° things that just cost money and don't really fix the problem.
Hope this helps,
Pete
When you install the distributor per the drawing, the tach cable will line up perfectly and you won't need to put a kink in it or buy one of those crazy 90° things that just cost money and don't really fix the problem.
Hope this helps,
Pete
Tech Contributor
Joined: Aug 1999
Posts: 14,377
Likes: 6,377
From: At my Bar drinking and wrenching in Lafayette Colorado
E-mail me for my distributor installation paper - it shows the correct installation so the cable won't break.
You don't have to pull the distributor up out of the block to re-clock it, and you don't have to determine TDC. You just shift the wires over 1 post and twist the distributor - then re-time the engine.
Lars
V8FastCars@msn.com
You don't have to pull the distributor up out of the block to re-clock it, and you don't have to determine TDC. You just shift the wires over 1 post and twist the distributor - then re-time the engine.
Lars
V8FastCars@msn.com
Burning Brakes
Joined: Dec 2007
Posts: 952
Likes: 0
E-mail me for my distributor installation paper - it shows the correct installation so the cable won't break.
You don't have to pull the distributor up out of the block to re-clock it, and you don't have to determine TDC. You just shift the wires over 1 post and twist the distributor - then re-time the engine.
Lars
V8FastCars@msn.com
You don't have to pull the distributor up out of the block to re-clock it, and you don't have to determine TDC. You just shift the wires over 1 post and twist the distributor - then re-time the engine.
Lars
V8FastCars@msn.com
