Pilot Dan

This past winter, I pulled the Tach in my 59 for rebuild to correct several problems. I reinstalled it along with a reproduction tach cable and it's still noisy. I test ran the tach with another short length of speedo cable and a drill and it runs quiet as it should. After much time and effort troubleshooting, I determined the Reproduction cable is causing the problem. It appears to be "floating" in the sleeve as the base of the tip is not in positive contact with the housing and the noise is coming from the base of the tip moving around. Also confirmed by the fact that the noise can be influenced by moving the back of the cable housing while the car is running with the thumb screw fully tightened.

SO, I went down to my local FLAPS and bought a generic replacement cable inner core and fitted it to my original old housing. That one tightens up OK, but the replacement cable tip is binding and won't turn when fully tightened. I could maybe flip the cable and have the hard tip in the generator end (backwards from how it is supposed to be). See photos below.

Here are the questions:

1. Has anyone with 58-61 Generator driven Tach experienced a noise problem relating to the reproduction cables??

2. Has anyone had any luck finding a replacement inner cable with a tip that fits the tach without binding? If so, where can I get one??

3. Should I try to reverse the ends of the replacement cable so the tip is in the Generator to get it to work?? Keep in mind the bottom of the tip has a shoulder which also shields the tach from grease (Not my first choice).

Here are photos of both:


REPRO CABLE ON LEFT, ORIGINAL W/ REPLACEMENT CORE ON RIGHT (NOTICE THE DIFFERENCE ON THE CABLE TIPS)


ORIG CABLE LEFT, REPRO RIGHT NOTICE THAT WHEN BOTH ARE FULLY SEATED, THE REPRO IS ABOUT 1/4 IN SHY OF BEING FLUSH WITH THE THUMB SCREW END, WHILE THE OTHER IS EXACTLY FLUSH.

Any thoughts, or information of where to go from here would be appreciated. TIA Pilot Dan

Frankie the Fink

Its been a few years but I'm pretty sure I got my repro tach cable from Corvette Central and (with careful routing) its been working fine for at least two years. My car did not have an original cable when I got it so I had nothing to compare the new one with so I just put it in and it works fine...

You may not know but there is a service bulletin about rotating the generator-mounted tach drive 180* if operation is erratic --something to do with cable slack. Anyway I can't say if this would help or not but might be worth trying.

Pilot Dan

Frankie I had rotated the Tach unit on my own some time ago (did not know there was an actual service bulletin for that) to better improve the angle of the cable at the Generator. Nice to know the factory agreed with me on that decision .

Frankie the Fink

I'm about 99% positive this is what I'm running: http://www.parts123.com/parts123/yb....Z5Z5Z50000050x

Pilot Dan

That's the replacement cable and they actually work better than the so called correct one I bought.

I was able to locate another replacement inner cable with the correct length tip this afternoon, fitted it to the original housing pictured, reinstalled it in the car, and now she is quiet as can be. Well, yet another crappy repo part that I wasted my money on. At least it's GONE now, and my Tach works smoothly.

1snake

I still have the original cable with the drive in its original position (down low) with no noise. If they are lubed occasionally, they will virtually last forever. The service bulletin addressed those that weren't serviced and was a quick fix vs. replacing the cable. Maybe that's why it didn't come out until after several years of production.

Jim

Pilot Dan

According to Frankie's post the SB came out early in 1960. I personally think that anything that can reduce the angles and bends in these cables is a plus. Rotating the housing did not solve the bad repo cable noise, but it did reduce the angle of the cable at the generator which makes for smoother operation in my book.

Stewart Allison

I also have the original inner and outer cable no noise but it's getting plenty of bounce. I will need to fix that eventually. I guess it's from the tacho rather than the cable ?
Dan glad to here all is well repo stuff can be horrific I always try to se original where it will let me. GM certainly made better stuff than China.