My speedometer needle bounces when I am traveling below about 35MPH. It has about a 10 MPH bounce. Once over 35-40 MPH it smoothes right out. Is there a fix for that?
Corey
Have you tried greasing the speedometer cable? Use white lithium grease.
I have tried nothing so far. So to grease the cable do you actually remove the inner cable from the outer sleeve and apply grease?
Quote from: silverton_ford on July 26, 2018, 04:06:46 PM
Have you tried greasing the speedometer cable? Use white lithium grease.
Lithium grease can dry out. I have always been told by the old speedo restorers years ago to use a graphite lubricant. Not to say that you can't use Lithium grease but it is not the best thing you can use.
Quote from: Bob Gaines on July 26, 2018, 05:12:53 PM
Quote from: silverton_ford on July 26, 2018, 04:06:46 PM
Have you tried greasing the speedometer cable? Use white lithium grease.
Lithium grease can dry out. I have always been told by the old speedo restorers years ago to use a graphite lubricant. Not to say that you can't use Lithium grease but it is not the best thing you can use.
Good recommendation on the graphite lubricant. I have used white lithium grease in the past and haven't had troubles, but I have seen it dry out in other areas of use, so naturally it makes sense that it would dry out on the speedometer cable too.
Quote from: Corey Bowcutt on July 26, 2018, 04:26:41 PM
I have tried nothing so far. So to grease the cable do you actually remove the inner cable from the outer sleeve and apply grease?
Pull the speedometer cable off the back of the speedometer and then pull the cable out of the plastic sleeve and grease the entire cable. Also add a little bit of grease on each end of the cable. I don't think you need to pull the entire sleeve.
I have done this on 70's Ford pickups and 60's Galaxies. I would imagine a 68 Mustang would be the same process.
Also make sure the cable is routed correctly and not bent or kinked. I think the easy way to access it is to take the heater control loose and let it hang, stick your left hand into the opening and take the cable loose, pull it over to the heater control opening and use a pair of needle nose plyers to pull the cable out, grease it up and work it back into the sheath. Reassemble and try it
might need a speedo shock absorber. pookie got em. phred
An old-time mechanic I knew always used 3 in 1 oil.
Pretty sure transmission oil migrates in from the lower end but not enough to lubricate the whole cable. I just remove inner and dip in motor oil.
Lithium grease is not stable and will dry out to hard powder over time, accelerated by heat. Graphite is the best for long term use that is why the cables have come with them originally for many decades. 8)
The speedometer head itself can also be source of needle bounce and have seen damaged nylon gears in the odometer cause it - kind of a "once around" increase in friction leading to speed up, slow down in the movement.
Kurt.
All great advice thank you guys very much.
One more question, when I pull the cable out from the sleeve from the speedometer side do I have to remove the gear from the transmission first and disconnect the gear from the transmission side of the cable?
You can pull it out leaving trans. end intact. When reinstalling just rotate a little till the square end slides into the driven gear on the other end.
Excellent! Thank you.
Quote from: Bob Gaines on July 26, 2018, 05:12:53 PM
Quote from: silverton_ford on July 26, 2018, 04:06:46 PM
Have you tried greasing the speedometer cable? Use white lithium grease.
Lithium grease can dry out. I have always been told by the old speedo restorers years ago to use a graphite lubricant. Not to say that you can't use Lithium grease but it is not the best thing you can use.
+1
NO LITHIUM GREASE!
https://www.macsautoparts.com/ford_falcon_mercury_comet/speedometer-cable-lubricant-special-graphite-type-1-2-fluid-oz-382709.html
A bounce like that can also signal that the inner cable is weakened. Mine was doing that. I took it apart and found the inner cable starting to come apart.
What I do, and I also do this on my 1970 428 with manual choke, for the manual choke cable.
Remove the entire cable. Take it apart. Use brake cleaner down in the outer part to get out all the old, who knows what lubricants.
Use some brake cleaner (and gloves) on some rags or paper towels to clean up the inner part (or just get a replacement). Inspect it.
Get graphite from your local big-box hardware store (ask for it over in the lock area). "puff" that graphite into both ends of the outer part. Use some compressed air to blow it down into the cable. Put some graphite on another paper towel and work the inner part thru that. Assemble together and onto the car.
Go for a drive.