62 Tach Drive Cable Bind

[Tom C.]

Does anyone know how I might reduce the stress on my tach drive cable on my 62 where it attaches to the distributor(without reeming out my firewall port with a rasp)? The cable has to bend at a 45 degree angle to attach to the distributor, thanks to the factory's location of the port on the firewall. I need to re orient my distributor so that the tach drive is more 90 degrees to the firewall. Could this be done by rotating the distributor to a different gear and also rotating the cap so that the firing order remains correct. Seems like a tricky deal so any tips from someone who has done it will help.

My new tach drive cable from paragon installed yesterday failed today thanks to the bend and stress I suppose..

Thanks, Tom Cheairs

[Paul J.]

62 Tach Drive Cable Bind

Tom, Corvette Central has a 90 degree cable drive adapter #272110 for $40.

[Greg S.]

Re: 62 Tach Drive Cable Bind

You are on the right track reorienting your distributor. There should not be excessive bind in the cable if the distributor is in correctly. The rotor should point slightly to the passenger side of straight ahead with the number one piston set to TDC. If it is not, your distributor is off. The distributor gear drive may be installed 180 degrees off or you have the distributor installed incorrectly on the wrong tooth. 14000 plus 62 corvettes had tach drive distributors installed without tach cables breaking so you must have the distributor pointing the wrong way..

[Tom C.]

Re: How about rotating the Distributor

Would it not just be a matter of lifting out the distributor and rotating it a few teeth counterclockwise (also turning the oil pump drive with a screwdriver), being careful of course that the rotor remains in the same firing position? Drive teeth are drive teeth I suppose...

Anyone see any problems with this solution?

[Alan Drake]

Re: 62 Tach Drive Cable Bind

I must agree with Greg - first find out why it is breaking (wrong position??)
Another thing to check is the lenght of the cable (not the cover)Cable will be a little longer! these are in inches;

For 62 their was a 1st design (5656347) L=37 1/8

2nd design (6478121) L= 40 1/4 and finally one listed as

62 all (?????) L=40 1/4

Have also foung a 62 ex FI w/HL cam (6478128) at L=62, howver that must be wrong!

Over the past few years it seems people do have problems with the cable fitting correctly. I believe the correct lenght must be used to avoid these problems, however that is only my guess (not fact).

[Larry P.]

Re: How about rotating the Distributor

Wouldn't you need to move the plug wires on the cap?
LP

[Norris W.]

Re: 62 Tach Drive Cable Bind

All you need to do is pull the distributor up and re-position it so that you can get the timing right with the distributor in the proper location to un stress the cable. When you get it where you want it, you can either trial and error rotate the oil pump shaft so it'll drop all the way in, or bump the starter which'll let it drop also. Keep in mind that if it's sitting on the oil pump shaft, as it drops it'll rotate slightly which'll change the position slightly also. It may take several trial and error attempts if you're not familiar with it, but it'll come to you after a time or 2.

[Tom C.]

Re: Repositioning the Distributor

Seems to me that the distributor doesn't care which camshaft gear it is engaged in. The only thing that matters is that the rotor is still pointed to the cylinder where the engine was last shut down and the oil pump is engaged allowing the distributor to seat into the manifold. I realize that the shaft must be rotated slightly to be removed and the same goes for reinserting it.

Someone please correct me if I am wrong. My dwell adjustment window now points to the 2 oclock position with 10 degrees of advance at 800rpm. Shouldn't the window pretty much face the carburetor?

[Dennis C.]

Yes *NM*

[Greg S.]

Re: How about rotating the Distributor

Once you move the distributor gear to reorient the rotor to point in the right direction you must move the spark plug wires to the correct towers. The number one cylinder plug wire must connect to the tower where the rotor is pointing. All others should follow in firing order. In theory the distributor rotor can point anywhere and the engine will run as long as all wires are placed in firing order. The downside is that the adjustment window or vaccuum advance will be in the wrong orientation and the timing mark on the balancer will not be useable.