speedo needle wobbles when driving over 80 kms per hour
When they assembled the speedometer cable at the factory, they filled the cable with bearing grease and then sealed both ends. This lubricant can leak out, deteriorate, or dry up over long periods of time. Without lubrication, the operation becomes noisy, but this is not the only problem. Since the cable runs from outside the car to up under the dash it takes a few twists and turns along the way. This can cause a binding situation that slows the cable down.
This results in a shaky needle that can make it difficult to read the miles per hour or at least drive you crazy trying to. Replacing the speedometer cable is one option, but there are two methods for lubricating the old cable that’s worth it to try first. For one method, they make a special speedometer cable lubricant that’s installed where the cable attaches to the speedometer head. This specially formulated penetrating oil uses gravity to work its way down through the cable.
The second method attacks the situation from the other end. Lisle tools and the help auto parts brand make a gizmo that connects to the transmission side of the cable. It’s called a speedometer cable lubrication tool. It has a Zerk fitting that connects to any standard grease gun. This allows you to pump fresh lubricant up inside the cable. This can often solve problems but is not always successful.
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Thanks this is very helpful
If the truck has cruise control there will be 2 cables. One from the transmission to the CC servo and the other from the servo to the gauge. Both need the grease and the problem may be in the servo.
thanks I did not consider the criuse control as a concern