i was driving my 327 and powerglide impala wagon... crusing along at 65 when the speedo needle suddenly pegged at 120 and made a screech that belongs in a horror house. I quickly pulled over and disconnected the cable at the back of the speedo head. anybody have any luck spraying some lube into the back of the head and have the speedo actually work again??
If the car had sat a long time sometimes the graphite cakes up I sprayed some WD-40 into the cable housing from the top and let it sit overnight then drove it and it went back to normal and after 6 years it still worked when I sold it.
From the way you described what happened it is past the point of needing lubed. Its gonna have to come out and be repaired.
Yea the cable and not the speedo is usually the culprit. I usually completely remove the cable and spray some sort of lubricant like WD-40 or Liquid wrench down there and let it hang to remove or break loose whatever crap is in there. Then they actually make cable lube that you can squirt in one one and let it flow down to the other end of the housing. put it back and you are golden.
Agreed, you need a full disassembly. Please don't use WD-40 on a speedometer, we use highly specialized avionics greases and oils at various points based on wear forces and metallurgical properties. Side note: speedometers need to be serviced every so often or they dry out and lock up, often costing you a cable or speedometer assembly.
You can buy a lifetime supply of speedometer cable grease at any parts store for $1.79. Detach the cable at the transmission end, pull out the inner cable, wipe it off with a rag, grease it and put it back. Do not grease the top 6" or 1 foot, you don't want grease working its way into the speedo. This should be done every 10 years or so. The speedo still won't work because the problem is not the cable. If the cable freezes the needle will jump around or stop completely. Your speedo is frozen up on the inside.
Usually that happens when it gets cold, and it hasn't been cold in AZ lately. You can try adding a drop of light oil to the back of the speedometer, too, between the threaded housing and the ferrule. But a speedo rebuild is in your immediate future.
been six years now and i wonder if anybody has come across a successful simple way to lube a stock speedometer without removing it from the dash yet. my drive cable is fine. i use my bicycle speedometer or phone app for the few times i drive it in the neighborhood. both my 41 cad and 68 chevy suffer from dry speedo.
Lubricating a speedometer while still in the dash and in one piece sounds much like replacing piston rings through the dipstick hole without opening the engine.
I use blinker fluid, works good. Seriously, when they scream and the needle pegs, it's time to rebuild the speedometer. It's not the cable when it does that.