Jumping speedometer needle
Thread Starter
Pro
Joined: Mar 2002
Posts: 610
Likes: 1
From: Bluffton SC
Jumping speedometer needle
My speedometer needle has started jumping below 20mph. Once the car hits 20mph it work great but below this speed it jumps from the needle seat up to any speed up to 50mph and back to the needle seat. Any ideas...bad cable, cable needs lubed??? How much of a PITA is it to just put on a new speedo cable?
Le Mans Master
Joined: Mar 2002
Posts: 7,456
Likes: 2
From: Coming home from Luckenbach Texas
Re: Jumping speedometer needle (914eener)
Most likely it's your cruise control transducer. A speedo cable runs from the tranny to the transducer, then another cable from the transducer to the speedo. All the catalogs list 'em, but you'll probably replace the stupid thing again in a few years!
Melting Slicks
Joined: Oct 2000
Posts: 2,143
Likes: 195
From: Englewood FL
Re: Jumping speedometer needle (914eener)
To test if the problem is from the cruise control transducer. Remove
the speedometer cable at the transducer which goes to the transmission.
Try turning the end of the fitting on the transducer that the cable was
attached to. If there is a lot of resistance, then the transducer is
binding up. Rebuilt transducers can be purchased from Napa auto
parts and Parts Advance. Test the new one by turning the same
fitting. I have purchased some transducers that are defective.
the speedometer cable at the transducer which goes to the transmission.
Try turning the end of the fitting on the transducer that the cable was
attached to. If there is a lot of resistance, then the transducer is
binding up. Rebuilt transducers can be purchased from Napa auto
parts and Parts Advance. Test the new one by turning the same
fitting. I have purchased some transducers that are defective.
Team Owner
Joined: Aug 2000
Posts: 21,457
Likes: 463
From: Massillon,Ohio USA
2020 C3 of the Year Finalist - Unmodified
Cruise-In VI Veteran
St. Jude Donor '08-'09-'10-'11-'12
Re: Jumping speedometer needle (mark79,80)
My Yellow L-48 4spd '80 also used to do this and it does not have cruise control. I replaced the speedo cable in about an hour and that took care of my "jumping" needle.
Cruising
Joined: Sep 2001
Posts: 12
Likes: 0
From: Lawrenceville NJ
Re: Jumping speedometer needle (914eener)
Take my advice and replace what ever it is ASAP. My 1969 started doing that and I let it go toooo long. The cable broke of on the back of the speedo and now I have to take the dash apart. I already put the new cable in place and that only took about 30 min. I wish I had done that before it broke. Good luck
Melting Slicks
Joined: Feb 1999
Posts: 3,078
Likes: 1
Re: Jumping speedometer needle (mroberts)
Taking the dash apart is not really that big of a deal. You have a 69, I have a 68, so I know it's similar. Yours is easier because you don't have an ignition switch in your dash. Just remove all the screws around the driver's side dash and remove the couple of bolts that hold the steering wheel up. That'll give you a much needed extra inch. Then pull the lower dash out from under the dash pad. Now you can reach the speedo, tach, the bolts that hold them on, and more easily get your hand back behind there.
Also, do not forget to pull the inner cable out of the speedo cable and lube it up good. You can use either siliglide (a silicon based lubricant for hoses) or white lithium grease.
[Modified by MoMo, 8:41 PM 9/15/2002]
Also, do not forget to pull the inner cable out of the speedo cable and lube it up good. You can use either siliglide (a silicon based lubricant for hoses) or white lithium grease.
[Modified by MoMo, 8:41 PM 9/15/2002]
Racer
Joined: Sep 2002
Posts: 252
Likes: 0
From: wellington N Zealand
Re: Jumping speedometer needle (914eener)
For a quick fix...check where it kinks into the box. put some lube in there and see if it helps.
I had a screwed cruise control so after many attempts to fix just bypassed it. :cool:
I had a screwed cruise control so after many attempts to fix just bypassed it. :cool:
