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A few months ago my speedometer froze after a drive and the cable broke the next day when I went for a drive. I finally decided to fix it and give my instrument cluster a tune up. This "little" project was 2 long days!

When I went for a test drive the speedometer was working for 8/10's of a mile and then it stopped. Crying, I turned around went back home to pull the cable and check the speedometer. Part way back I stopped to take a little video of my dash and when I started again my speedometer was working. What the heck!?!? Parked in the garage pulled the cable, seems fine, checked the speedometer and it's fine too. Slide the cable back in and it seem to engage in the drive at the transmission, so I'm a bit flummoxed.

Went for a second drive and no speedometer again.

Could the drive at the transmission be out of position? Can that happen? I took it apart to recover the broken piece of speedometer cable a few months ago and maybe it didn't quite go back into the correct position, if that's possible. If the speedometer and cable are okay, then the drive seems like the likely culprit.

Help?

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The cable core may be a little too short, or the cable core socket at the speedometer shaft or drive gear may be worn, or the drive gear itself may have badly worn teeth that allow it to slip. I'd look first at the drive gear and inspect the socket that the end of the cable core fits in to. Cables need some lubrication. I'd look for expert advice on that. Too much lube can cause trouble. Your speedometer shaft needs some lubrication, too. They can get dry and stiff and cause problems.

Tx Goat:

When I slide the cable in I can tell it is going into the drive at least 3/4", or more, so I don't think that is the issue.

It's possible it's the socket on the drive, but when I insert the cable and try to turn it's solid, so I don't think so.

Cleaning the froze speedometer was the start of this project so that is all good.

I think I'll pull the drive gear and see what's going on there. It appeared to be in good shape when I had it out a couple of months ago, which is why I wondered if it could be out of position a bit and maybe not fully engaging. It seems to me that the issue must be related to the drive gear.

The adventure continues!

Take a drive with the cable unhooked at the speedo and watch if the cable turns. Try and stop it with your fingers.Does your replacement cable core have a pressed on fitting at the upper end? Most replacement universal cores do, and it could be slipping inside the fitting. Just crimp it.

It is all but impossible to assemble anything wrong down at the trans end if you have Ultra. It simply won't go. It is conceivable that you have lost a tooth on the drive gear down at the trans, but that would be the first one I have seen in 50 years.

I've had a few Ford drive gears wear out to the point of slipping, usually on a cold morning. These were nylon gears.

Speedo cables don't like sharp bends. Route the cable with gentle curves, so far as is possible. They don't like heat, either.

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Thanks Ross! You know we all like to hear from Ross!

I'm Using the cable from my 53 Patrician parts car, so cable should be the issue. I'll take it for a drive with it disconnected later and see what happens. Very strange to me that it would work, then stop completely, then work again, then stop again.

I am 99.9% sure the cable is fully engaged in the speedo and that the speedometer itself is problem free. Could driving it a few hundred miles with out a speedo cable have caused damage to the drive gear? Doesn't seem like it should have. The drive gear was good enough a few months ago to break the old speedometer cable, so not sure why it would be an issue now.

I'll do some more checking and looking and report back what I find out.

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I might have to take it apart and have a look so I know for sure if the drive gear is causing the problem. I'll let you know what I find out.

Definitely check it's turning. You can do that in the drive with some rear stands or on a lift. Not sure if cable will jump out of place disconnected and turning at road speed.
It's most likely in the "clock" mechanism that turns the needle/dials since it's intermittent and cable is good. Usually if the drive gear reduction is bad/stripped it won't work at all and I've never had one go on any of my >100K mi vehicles Some of those internal speedo gears/parts are usually plastic. Since it hadn't run in a while it's maybe seized a bit. There's usually a little grease on them which can harden. It's a 70 yr old piece like me, I don't work all the time anymore either... Might just need a good cleaning.
Frankly if it isn't making noise, I wouldn't worry about it. See if it starts again. You're way past odometer laws and a GPS will give your speed much more accurately. There's apps for that.
The speedo can probably be repaired but I don't know about getting Packard parts or who made their's. I send those parts out let others worry or replace.
The cables usually break from lack of lube and fatigue/wear. Used to be pretty common replacement items until digital dashes. So much so they came out with the "universal" cable which had its issues ala Ross.
I used to have a GM speedo cable luber from back in the day, but don't know what happened to it. I guess someone borrowed/lifted it from the old man's garage after I left. I haven't seen any since. Short lived invention. Then there's the graphite vs non arguments, but white lithium is OK by me. Don't need much. Maybe I should market "genuine synthetic" speedo cable lube?

So the problem is my stupidity. 🙄

The cable that I replaced my original one with was a bit longer, and the squared part wasn't as long, so I modified it a bit. But the solder only went a short ways compared to the original. When I went to square off more of the cable it was only cable and instead of it being square I ended up with just the round inner core for about 3/8".

I figured it wasn't ideal, but instead of waiting and getting it repaired, or a different cable, I popped it in anyway.

But as luck would have it, that narrow spot lines up exactly with where the shaft of the drive engages the cable. So it would hold a little, and the speedometer would work, and then it let go and quit.

So two lessons. 1. 53 Cavalier and Patrician speedo cables are just slightly different. 2. If you're having troubles with something that you worked on, good chance you are the problem!

At least it's a simple fix, and no harm done.

A project for this evening!

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Good job at solving the issue! However (and I haven't looked at the parts book), I can't imagine that the Cavalier and Patrician would have different cables unless one or the other had gotten replaced at some point with one from, maybe, a junior model.