I've been trying to fix the bouncing needle syndrome and have not had any success. Last Saturday, I removed all parts except the speedometer. I cleaned and put new lubrication on the cable and the sending unit in the transmission. While putting everything back in place, I used a drill to make sure the speedo was OK and it bounced until around 15 mph and then the bouncing stopped.

Driving the car that night, the speedometer worked like a champ. Not a single bounce over 15 mph. I drove the car today and the bounce returned until the car warmed up.

What is the problem with the bounce? The parts are fine and cleaning them worked for a while, but not long term.

Here is a thought. While installing the sending unit, I noticed that the spindle (for lack of a better term) could move back and forth in the retainer. If the cable and the spindle moved farther back in the transmission, would this cause the slipping between the cable and spindle, which would cause the bouncing?

I am at a loss. Any help would be appreciated!!

 

if you have cruise control the module on the left fender where the cable goes is usally the problem, its about a $100 fix

 

Thanks, but I forgot to add that I do not have cruise control. It is just one cable running from the trans to the speedo.

 

How did you lube up the cable? I've seen the bit that allows you to attach a grease gun, but it runs almost the same price as a new cable. I've got a bad bounce from 60mph up. I've been debating on just putting a new cable in my '80.

Nice to see another person from JC on here. So far it is just you a JDs00pewtercoupe. I moved to KC from there in '98. Still have family and a few friends there.

 

If the cable is old, might as well try a new one as they're only like $9. I had to order my cruise control transducer, it was like $70 at kragen.

 

...replaced the speedometer cable on my non-cruise control 4spd '80 I used to own and that's all it was-a worn speedometer cable.

 

Wow must be something other than the cable causing it because I have this problem and thought a new Keisler TKO tranny and new speedo cable would solve it but it is still there

 

AK. Mal - There are very few C-3 or older Vette's in this part of the country. I have seen JD's C5 and it is a nice Vette.

Thanks for all of the advice!! I'll try a new cable and see if that is the problem. I'll update ya'll when I get everything installed.

 

Andrew
My speedo on my 79 was doing the same thing, changed cable and works great now.
Are you aware of the Mid Mo Corvette club? I think it is in Columbia. They have a great car show for vettes on the 1st weekend in April. Been going up there for the last 6 years......LT

 

ha... if you think it bounces bad at 60ish... u should see her go at 130

 

Sometimes the bounce is from the cable but alot of times its from the speedo itself.Theres a few different things that can cause this trash in the speed cup,spring binding and main frame wear can all cause these to bounce.It seems that the 78-82 Corvettes bounce worse than others mainly due to the needle itself...the light weight plastic needle doesn't have much of a dampening factor to it at all.
You might want to have your speedo checked out.

Someone mentioned one of those "cable lube attachments" I would STRONGLY not recommend using one of those.Its a piece that goes inline and you pump grease from a grease gun up through the cable...The problem is that all that grease that you pressure through the cable will also sqeeze into the internals of the speedometer itself and it unbalances the speed cup...no telling how many of these I've seen.

Jason
VetteInstruments@aol.com

 

IF not the cable and any graphite or light oil like WD40 dont fix it, you must take the speedo head apart.....complete disassy....get it outta the car, that't the hard part, then on a clean kitchen table with lotsa light, sit down and carefully take the instrument apart, the spot you are going for is internal to the unit itself, and it's a needle bearing that sort of floats in the middle of things....inside the magnetic cup spinning over top of the rotating magnet...yout will see wht I mean when you take the needle off by pulling straight out they get stuck there pretty good over time, then the compass card off, then you see two screws holding a U shaped frame part of the zinc castings...
you take them out and carefully pull the assy apart, you will see a needle fitting into a little cup type thingy that centers the two assy's....that is what needs a dap of carb cleaner, and a q tip worth of WD, then put it all back together while lubing the input shaft with some WD/lightest machine oil you can...

jack the car up properly and do a test run before installing permanently in place....

GENE (who has fixed many of these speedo movements in various old cars)

 

I had the same problem on my 78 non cruise control unit. I tinkered with the cable and gear in the trans for I don't know how many times. It drove me nuts at Ocean City Cruisin one year and I pulled over on Ocean Highway jacked up the car with the ole sissors jack and disconnected it at the trans. When I crawed from under the car and stood up the car rolled off the jack. A couple of seconds and I would have been history. I finally took out the entire speedo assy and sent it off for a complete rebuild and new face. It's been working great ever since. Plan on sending out the Tach for the same thing within the next two weeks.

 

I used powdered graphite and a light machine oil on mine. made kinda of a tape funnel, sprinkled graphite in, worked the the cable itself back in forth inside the cable jacket, it takes awhile but I got some of the graphite in, and then I put the light machine oil in.

 

I took the expensive fix route, just ordered the complete digital dash setup from nordskog performance/ Now I'll probably have bouncing digital LEDs.
ESU

 

Try lubing the speedo cable again. The first time I lubed mine, it lasted three days then started bouncing again. Pulled the cable out and added more lube and that did the trick. No bounce for six months now.

Peter

 

I know of a 3x,xxx mile '69 in Taos. I believe the fellow who owns it has another low mileage chrome bumper shark as well as a '69 Camaro.

 

Sometimes you can put 10 cables in and it wont cure the problems.

The cable housing along with a new cable has to be replaced.
They are both "wear over time" items.
Do not pump grease...a hand job with light grease is ok (not that kind of hand job ) on the new cable itself and then installed in the new housing....then back on the car.

If that dont work; then its time to tear into the speed-0 itself for a cleaning and parts check.

If your car has the original mileage showing...do your best when you tear into the speed-0 not to tamper with the odometer...mis-alignemnt of the numbers is usually an indication the the odometer has been tampered with.


My .02 sensor,
Jim

 

I have a replacement cable/housing ready to install. My lube gun has Amsoil synthetic grease already loaded. Any issues coating the cable with this?

 

Hmmmm... I didn't have the problem until I put the new Keisler 5 speed and new cable on... now bounces from about 5 mph to about 40. Keisler just sent a new shorter cable... It's in...but Have a small problem testing right now...