Troubleshooting help on a '41 Packard

[1935Packard]

I'm getting a strange sound underneath the dash of my '41 110, and I could use help figuring out what it is. The car starts fine, but as I drive away and get to about 10 miles an hour, I begin to hear a cyclical sound underneath the dash near the speedometer. It sounds like loose metal parts touching each other, and its frequency roughly correlates to my speed. When I get below 10 miles an hour or so, it stops. It makes noise for about a minute or two, and then it goes away.

Any ideas? Maybe something in the speedometer needs to be lubricated? Thanks in advance for the help.

[Dave Mitchell]

Try lubing the speedometer cable with some graphite.

[West Peterson]

Lube the speedo cable indeed. If you don't, the sound will quickly worsen, and before you know it, the cable will snap (I know this for sure). You can easily test to see where the problem emanates by easily (if you're a contortionist) unscrewing the cable on the back side of the speedometer.

When I replaced my cable, I lubed it with grease, not graphite. You need to use grease sparingly, though, or otherwise it will work its way into the speedo housing itself and cause a mess. I can't remember the type of grease I used at this time, but I'll get back to you on that. The only way to do it is to disconnect the cable completely from the transmission and take it out of the coiled sleeve.

Edited November 15, 2011 by West Peterson (see edit history)

[Bleach]

X3 on lubing the cable. It needs to be removed as was suggested above. I had a issue with my Cadillac actually snapping the cable without warning. The problem was solved by completely lubing the cable and case.

[1935Packard]

Thanks, guys. Much appreciated.

[4t1pack]

If your noise sounds like a telegraph, you should look to your windsheld wiper motor. Try truning it on and off when you hear the noise.

Saltydog

[West Peterson]

Here are the instructions I was given:

I cleaned my speedo inner cable with kerosene, dried it with lint free cloth, then wiped the entire cable with lithum grease (the kind you pump into tie rods and such). Before inserting the inner cable back in the jacked outer cable, I worked an excessive amount more grease into the speedometer end of the outer cable. Then I slowly twisted the inner cable into the outer cable from the speedo end.

The result of adding lots of lube to the outer cable and twisting in the inner cable was to get as much in as possible; obviously, some grease pushed out, but I knew I had it covered.

Side notes:

Note 1:Since most cables (especially NOS) have been stored in a spooled up condition, they will retain a bit of curved shape. I believe car shows the effect of that in that you can occasionally hear a pulsing sound of scraping of the inner cable to the outer cable. I expect the solution to this is to do something to remove the curve of the inner cable due to storage and to also not subject the overall cable to bends that are too tight or sharp. I think if a new cable is being installed, or one being serviced, it may be possible to gently draw it through your hands to undo the bend due to storage. The risk is, of course, that you kink it in the other direction. Perhaps time and usage will also undo this.

Note 2: Never hurts to add a bit of transmission oil to the top end of the cable. Its thick, filmy such that it sticks, and if it ever drains, it will drain to the transmission. The oil will not rinse away the grease (unless you force it out by displacement).