Speedometer Needle Bouncing?

(2011-08-10 14:20:17)

1. Bryan Werling Says: I have a 89 Ford Ranger. The speedometer needle keeps bouncing when i drive. Not like all over the place but when im going like 15 miles an hour it'll be bumping just above 15 to about 22. if im doing 35 itll be just above 35 and going to about 42. (i tested via gps). so what could the problem be. could it be the cable. idk. i can keep it like this but would rather have it fixed but don't want to take it to a shop. i'm very mechanically inclined i just don't know about this part. yet.

2. Treva Says: all of those old type speedos bounce like that until you get to around 40. It's normal don't worry about it.

3. norski Says: It is your speedometer cable. You can get a cable kit at your local parts store or you can see if your parts store knows who can make you up an entirely new cable and housing assembly.

4. Chris Says: if you pull the cable off at instrument panel you put white grease on it and slide it back in

5. BI-POLAR ANGLE Says: speedo cable is bad

6. Ash Purady Says: There are three common reasons for this in cars equiped with electronic speedo gauges.
#1- A dirty or faulty ground connection on the instument cluster harness. Finding the harness and a wire that grounds to the firewall is a starting point. You may have to improvise a new ground from a point where the ground wire is accessible for troubleshooting purposes if the actual firewall connection is behind the dash or console.
#2- A dirty speed sensor or connector. This is usually mounted on the transmission or 4WD transfer case. Try removing and cleaning the sensor and/or connector. This part is usually cheaper to replace than a gauge cluster
#3- Poor gauge cluster connections or gauge failure: Try just removing the cluster and cleaning the contacts at the back of the cluster with contact cleaner making sure no cleaner gets on the plastic or in the gauge(s). If this doesn't fix the issue, replacing the cluster may be necessary. To save money, You can sometimes use an old working cluster's parts to just fix yours if you are handy with electronics. Replacing the entire cluster means your odometer mileage will be different and this would need to be reported to the local DMV or DOL before doing the swap. It may actually be illegal to swap clusters in some jurisdictions. especially if the odo mileage is lower in the new cluster)
Hope this helps !
*** On much older cars equipped with mechanical cables the cable often got bent and the wire broke or froze in the cable sheath.

7. roger Says: this is common for a lot of vehicles , especially older ones with the mechanical cable, I have a van now that does this while speedometer is cold, once it gets above 40 its not a problem, I personally don't think its worth the hassle of figuring out which cable ends to buy, disassembling the dash board in some cases to gain access then going into the transmission end, if any of the plastic gears in the transmission get damage in the process it gets more complicated. I leave it alone unless the speedometer is broken or gets stuck.
I have driven for years with no speedometer, I found one of those radar trailers on the side of the road figured out where 25 miles per hour was using the engine rpm and could adjust speed up or down accordingly, On the freeway, I knew what the rpm was before the cable broke so I would just keep the rpm right like that, and keep an eye on the truckers. If they were all at 55 it was reasonable to find a cop somewhere nearby, and if all the truckers were high ballin at 60 plus we had a nice cruise.