Home page
SPONSOR AD

Topic: tach and speedo cbl problem

in Forum: C3 Engines


tach and speedo cbl problem

Posted: 10/2/03 10:41am Message 1 of 5
Lifetime MemberLifetime Member
Send PM
MENTOR, OH - USA
Joined: 9/15/2003
Posts: 577
Vette(s): 1979 L-82, dark blue
I have an annoying problem with my lower speedometer cable on my 79 L82, auto. I just broke the 3rd one in a year. Anybody experiencing the same thing? Any ideas? Solutions? (besides diconnecting it).
Also, my tach only works above 3250, approx, rpms. When at idle it will register 4200 and when driving, it will register 3250 until the rpm's exceed the 3250. Under acceleration gears shift at approx 5500 rpms.
I have seen new pc boards for sale that advertise they will fix 99% of tach problems. Is this the route to go?
Any input is appreciated.
Hank


SPONSOR AD:: (Our Sponsors help support C3VR)

tach and speedo cbl problem

Posted: 10/2/03 3:06pm Message 2 of 5
Profile Pic
Former Member
Send PM
Frederick, MD - USA
Joined: 9/8/2003
Posts: 3398
Vette(s): 1969 convertible L71 427/435 4-speed black interior
My '78 lower cable broke several months ago. It was the plastic gear where it goes in the transmission. An easy fix, but annoying nonetheless. Maybe there's a better gear available than plastic, or maybe it's poor quality manufacture. If you've been buying the cables from the same supplier, maybe buy one from a different vendor. It may make a difference. See if you can buy NOS GM parts.

Gunslinger
Frederick, MD
'78 L82


tach and speedo cbl problem

Posted: 10/3/03 5:00am Message 3 of 5
Lifetime MemberLifetime Member
Send PM
MENTOR, OH - USA
Joined: 9/15/2003
Posts: 577
Vette(s): 1979 L-82, dark blue
Gunslinger,
Thanks for the thoughts. Think I answered my own question on the cable though while I had my head under the hood last night. I think the cruise transducer is causing the problem. Hasn't worked since I got the car. May be binding just enough to cause the wear. Didn't replace it because I thought my budget $'s were better spent elsewhere. Looks like the plan changes once again. Do you know a good source for one?
Hank


tach and speedo cbl problem

Posted: 10/3/03 5:23am Message 4 of 5
Profile Pic
Former Member
Send PM
Frederick, MD - USA
Joined: 9/8/2003
Posts: 3398
Vette(s): 1969 convertible L71 427/435 4-speed black interior
I also recently replaced my transducer because I was getting a lot of speedometer needle bounce. This is indicative of either a bad transducer (your speed moves up and down in cruise mode), or a speedometer cable in bad need of lubrication (or both).

I found the best deal on a transducer was M.C. Corvette Services (The Last Detail Corvette Parts). Their website is <www.CorvettePartsDepot.com>. Their price on the transducer was $67.00 plus core, at least $20 below every other vendor I found. The core was about $8.00. They gave great service and the part works fine.

I hope you have small hands...replacing the transducer is not difficult at all...if you have small hands. My big mitts came out a bit bloodied and sore working in such a restricted area. Now, if you remove the master cylinder first, it's a piece of cake!

Best of luck.
Gunslinger


tach and speedo cbl problem

Posted: 10/3/03 8:44am Message 5 of 5
Lifetime MemberLifetime Member
Send PM
MENTOR, OH - USA
Joined: 9/15/2003
Posts: 577
Vette(s): 1979 L-82, dark blue
Thanks again Gunslinger. Will look them up. I've had the transducer out before trying to get the windshield washer fluid resevoir out. You're right. It was tight, but got it out. Had no luck with the resevoir though. Looks like you have to remove the master cylinder for that. Won't do that until necessary.
Hank


in Forum: C3 Engines


SPONSOR AD: (Our Sponsors help support C3VR)