62 Tach Cable Routing
Thread Starter
Racer
Joined: Feb 2004
Posts: 264
Likes: 0
From: Central WI
62 Tach Cable Routing
So I installed my new tach cable on my 62 last night. After a bunch of fiddling I finally got it on the tach. I routed it through the hole in the fiberglass that is slightly above the steering column where the speedo cable goes through. Only problem is I can't get it to hook up to the distributor. It seems like either I don’t have enough length or my distributor is off a tooth as the angle of the tach drive compared to the firewall is pretty extreme and requires quite a bit of force on the cable to get it to even come close to going on. It looks like I could pick up a few inches of play if I routed the cable from the side of the steering column behind the oil pressure and amp meter instead of going through the hole in the fiberglass. But looking at the paragon catalog it looks like I routed it the right way. Can anybody give me verification on this?
Thanks,
Scott
Thanks,
Scott
Team Owner
Joined: Oct 2000
Posts: 38,897
Likes: 1,926
From: Washington Michigan
As I recall, the '62 tach cable goes through its own hole in the dash, directly behind the distributor, slightly toward the passenger side from car centerline; it doesn't go through the same hole as the speedo cable. This is shown in the Assembly Manual. Maybe "62Corvette" (Mike) can confirm - he's had 28 of them. 
Burning Brakes
Joined: Mar 2004
Posts: 1,108
Likes: 4
From: Plano Texas
Scott, I just had to replace my 62 tach cable last weekend because it broke and failed. My car was originally a fuelie with a hole in the firewall to the left of the centerline of the vehicle and behind the distributor. However, my car is currently set up as a 340 HP carburetor engine with a vacuum advance single-point distributor. When I routed my cable originally (about 3 years ago), it had a severe bend where the cable attached to the distributor. The severe bend was created to be able to access the firewall hole for the fuelie distributor cable entrance. Unfortunately, the cable broke and I have had to replace it. To keep from having the same bend in the cable, I had to use an X-Acto hobby saw to elongate the existing hole to the centerline of the vehicle to allow the tach cable to pass thru the firewall with no bend. You should have a factory hole in the firewall behind the distributor for the tach cable, even if it was an original carburetor car. If not, you could drill a small hole with a hole saw (for residential door latchsets) and route the cable through. Good luck.
Mark
Mark
Melting Slicks
Joined: Jul 2000
Posts: 2,097
Likes: 99
From: Boston MA
JohnZ's right. The cable goes through the firewall at a hole directly behind the distributor. If the distributor is installed correctly. the fitting for the tach cable directly faces the hole. That is, the fitting faces the centerline of the car. On FI models, the hole is a little to the LH (driver's) side. But not by much. Not enough to make any difference in how the cable goes.
There's a rubber bellows that goes around the cable and mounts to the hole to seal off the hole. Paragon Corvette thinks that there's also a chrome mounting ring that goes around the bellows and the hole. But the AIM doesn't show the ring. I've got 2 of them, bought many years apart, and both of them are way too big to fit the hole.
There's a rubber bellows that goes around the cable and mounts to the hole to seal off the hole. Paragon Corvette thinks that there's also a chrome mounting ring that goes around the bellows and the hole. But the AIM doesn't show the ring. I've got 2 of them, bought many years apart, and both of them are way too big to fit the hole.
Thread Starter
Racer
Joined: Feb 2004
Posts: 264
Likes: 0
From: Central WI
Thanks for the replies guys. I guess I didn’t describe my routing well enough. The cable comes out of the hole right behind the distributor in the firewall. Where I routed it with the speedo cable is under the dash. There is a hole between the gauge cluster and the firewall under the dash that is above the steering column maybe four inches. The hole is about a inch and a half in diameter judging by feel. It sounds like my distributor is off a tooth or two since the tach drive is at a 45 degree angle towards the drivers side instead of tangential to the firewall. My vacuum advance was disabled on the car I think back in it’s race days so that might be why the angle is a little greater as well. I should probably unblock the vacuum port and get the vacuum advance working again. It might give me a bit better gas mileage than the 16 mpg I’m seeing now.
