1950 Speedo Cable Problem

[fmackan]

Hi everyone. 1950 Series 62 Sedan. My Speedo cable is failing. O-30 mph is fine. Over that it starts jumping and making grinding noises.

I went to try and unhook it from the cluster today to try and grease it but i found it practically inaccessible.  Can't get my hand or a wrench on it. Any advice?  I also have a new pre-greased cable as well

Second question. So knowing I am seeing my mechanic next week I was going to unhook it at the transmission as it's a 2 hour drive and I don't want unnecessary damage. Will the tranny leak via that cable connection while driving?

Thanks in advance

Francis Mackan

[signart]

It helps to be a contortionist, when performing this task. Try to employ a young, skinny kid to help and feel his/her way up the speedo cable housing and turn the knurled end cc.
Before you remove the housing and especially the cable from the housing, drape a drop cloth across your upholstery as a precaution. Do this as to prevent the cable, which will squirm wildly after it is removed from the housing and will contain containments that will not be removable from cloth upholstery.

Removal of the cable housing from the trans should not result in fluid loss if the seals are good in the transmission cable receptacle.

[fmackan]

I have tried every which way to get at it....the cable for sure is original as it is a 59K mile car, so I am resigned to the fact that I am having it replaced professionally.  I think the head needs to be cleaned and oiled and tested..and hopefully not damaged.  If I drive it and the cable stops/breaks then that's ok...i have a prelubed cable in hand ready to go..if the head is damaged, then i am for sure not making it worse

otherwise the car runs like a champ

Francis

[Lexi]

Depending on where the resistance is in the speedometer's mechanicals you risk ruining the gears in the cluster. Some might even be vinyl back then but not 100% sure. I know on the '56 there is a brass plug, say 1/4" across, that must be pryed out to lube a critical spot, near the cable area. Might be same on '54 but not sure. Don't think covered in the shop manual, but was told by an odometer rebuilder. Outer rear shell of the cluster must come off to access it. So, the cluster has to come out. Big PITA. And a potential cluster F*#k as well! Clay/Lexi

[fmackan]

Hi Clay. I am kind of at a loss as I don't want to remove the cluster myself. I also have a 100 percent complete restored cluster from McVeys ready to go if we had to. But I need to get the car to shop.

So the
Plan is to drive it and hope an get away with just replacing the cable.

[V63]

Yes, Simply remove the cable from the transmission.

Temporarily Secure it to the frame.

It should not leak.

[Hillbillycat]

Hmm, I´ll chime in for mine is doing the same. But my cable is new and I had flooded it with graphite powder before installation.
All was fine untill the tranny had to come off for reasealing two yeas ago. I suspected they had kinked it at the shop. But now I had disconnected the cable, rerouted it from under the dash and felt with my finger if it was turing even while driving. It did well, so I really think it´s the gears in the speedometer.

Not looking forward to take it out......

Oh the old cable was a PIA to take off of the transmission when I changed it. The cap nut disintegrated and left the threads on the stud. Had to scrape each turn off with severyl picks to free the threads.

[Lexi]

Hi Clay. I am kind of at a loss as I don't want to remove the cluster myself. I also have a 100 percent complete restored cluster from McVeys ready to go if we had to. But I need to get the car to shop.

So the
Plan is to drive it and hope an get away with just replacing the cable.

Hey Francis. Mine is also acting up and has for years. Probably going to dig into this during the summer. Had my Caddy out for a 52 mile run today and out of the blue the speedometer stylus starting jumping from around 45 mph up to 75+. Not good. Never did it before at this time of the year, usually only when cooler. These conditions also don't improve on their own unless remedial action is taken. Anybody have any suggestions as to what are the best lubes for the gears in the cluster and also the speedo cable itself? Not looking forward to this project, especially trying putting back in some of the trim screws when removing the dash top. Some just don't want to go back in easily. I know it sounds crazy, but I would be embarrassed to say how long it usually takes me to put the trim back on. Watching a Horror movie is less frightening. LOL  Clay/Lexi

[Cadman-iac]

 Hi Clay, Francis,
 Typically what causes the speedometer to jump like that are the bushings that the impeller, (for lack of a better description), and the needle shaft rides in are worn or dry.
 The impeller is the piece that the cable itself is inserted into, and it rides in a larger brass bushing, or sometimes a pair of bushings, and it's the piece that has the magnet on the end/top that causes the bell,(again, for lack of a better description) to move the needle. The needle shaft is supported on the bottom end in a very small bushing in the top of the impeller, and the top of the needle shaft is supported in another bushing just below the needle itself.
 When everything is within tolerance, the magnet/impeller will be spun by the cable, which in turn will cause the bell/needle to move from the magnetic force upon it.
 But over time the bushings wear, and this causes a bit of shimmy between the parts, and the impeller and bell sometimes contact and will fling the needle. The bushing between the two is the one that usually causes the issue, but the impeller bushing(s) can make the most noise.
 The gears in the speedometer are only to drive the odometer, and usually don't cause any problems. Greasing them will only cause them to attract dust and dirt.
 The problem with trying to replace the bushings is just finding a new one, as the lower needle bushing is extremely small. If it's not the same as, it's almost the same as the bushing in a cruise control transducer between the driver and the bell.
 If you are wanting to try to correct the wild needle, you will have to remove the cluster assembly and take the speedometer head out of it first. Then you can take it apart to access the bushing between the two pieces, and just a drop of some light oil, like sewing machine oil in the bushing, and reassemble it.
 But I would caution you that if you're not familiar with a speedometer that you may want to take it to a specialist. If you break a piece, you'll have to find a replacement part.
 The good thing about these is that underneath the face, most GM speedometer are the same.
  Hope this helps some.

Rick

[fmackan]

This is great everyone thank you. The car is going to a professional restoration shop. Not going to take the chance on disconnecting at the transmission. Will drive it with the jumpy needle.

Will follow up with the results

Francis

[Hillbillycat]

Hi Rick,

thanks for the clarification of the parts that are involved with the noise/jumping. Now I know what to look for when I take it out.
Wouldn´t it be wise to take it to your trusted watch repair man for cleaning and especially lubing with the correct oil?
I did that with the clock on my 56 and it works like a charm now (after laser welding new contacts in - the old ones had totally burnt out).
At least on a mechaincal clock the correct lube for each part is very important. And they´re a few.

Is there a good advice on what to avoid while taking out the cluster or a good tip?
Had the dashpad out and cluster loose for repair of my fuel gauge once but back then the speedo was working alright so I didn´t go ahdead and pull the whole assembly.
Pull the steering column?
I remember the big wheel was in the way almost all the time. Pulling the wheel off of the column without damaging the horn insulator I can´t imagine is impossible. I did get the wheel off only with the wire pulled out when the brass sleeve had to be replaced anyway and the whole column was on my bench.

[Cadman-iac]

Hi Rick,

thanks for the clarification of the parts that are involved with the noise/jumping. Now I know what to look for when I take it out.
Wouldn´t it be wise to take it to your trusted watch repair man for cleaning and especially lubing with the correct oil?
I did that with the clock on my 56 and it works like a charm now (after laser welding new contacts in - the old ones had totally burnt out).
At least on a mechaincal clock the correct lube for each part is very important. And they´re a few.

Is there a good advice on what to avoid while taking out the cluster or a good tip?
Had the dashpad out and cluster loose for repair of my fuel gauge once but back then the speedo was working alright so I didn´t go ahdead and pull the whole assembly.
Pull the steering column?
I remember the big wheel was in the way almost all the time. Pulling the wheel off of the column without damaging the horn insulator I can´t imagine is impossible. I did get the wheel off only with the wire pulled out when the brass sleeve had to be replaced anyway and the whole column was on my bench.

It's been over 6 or 7 years, maybe more, since I've removed the dash from my 56, and my goal was total disassembly so I could begin the restoration process on it. I can't remember if you have to just drop the column or if it's necessary to remove the wheel, it's just been too long now.
If you have a service manual, you might want to check it for more information on that part.
Once you have it out though, you will need to separate the two halves of the housing in order to remove the speedometer head from the rear housing. I think there's just 3 screws right around the area the cable attaches. Don't remove these until after you have separated the housing, or the speedometer will be loose inside while you are flipping it over and you could damage it.
I guess I should ask, you are referring to your 56, right?
Once you have the head out, the black background piece will have to be removed before you can get to the mechanism.
This is were specifics on what is next are vague now. If you are serious about doing this, pm me and I'll see what I can do for you. To refresh my memory, I will have to pull out one of my clusters and take it apart. I can post pictures here for you, as it's not possible in a pm.
I remember how, I just don't remember specifics, and I don't want to give you the wrong information. These are hard to find any more.
And I want to give you the steps for the Cadillac speedometer, not the other brands I've also done. It's easy to confuse them after so many years, and I've done others since I did the Cadillac speedometer.
For instance, I've added an electronic cruise control to my 64 Chevrolet truck by adding a "window" to the housing and back of the speedometer head so
the laser pick-up can "see" the back of the impeller, and added a 100,000 number wheel to the odometer,so it doesn't just roll over to 00,000 when it reaches 100,000 miles, which I had to enlarge the background opening for so it could be seen.
Then I needed to repair the trip odometer on both of my Suburbans, one because it stopped working, the other because it wouldn't reset.
So like I said, specifics are vague. Let me know what you want to do and I'll try and help.

Rick

[Hillbillycat]

Thanks Rick,
I´ll come back to you when I pull it. Probably winter. Want to use the car as much as I can now with the cold and rainy spring being over we had in Germany.
And yes, 56 it is.

[Cadman-iac]

  That's a better time for me as well.  I'm trying to catch up on a year and a half's worth of yard work after being laid up with a neck problem.
 Just let me know when you need help and I'll dig out a cluster and get some pictures for you.

 Rick

[Hillbillycat]

Well, took the car to my pal´s shop this evening and hooked up a cable from his scrap bin. No needle fling, no noise (as fas as I could tell from the noise the power drill made), just even needle action along the whole range.
This would confirm my guess of the kinked cable when the shop dropped the transmission.

I´ll order a new cable and see if that eleminates the issue. Much easier task.
Any idea how to get the new firewall grommet over the cable end nuts? Submerge the grommet in hot water and then use lubricant?

Side note:
I also noticed that the 1/4 brass plug COULD be reached with small hands and a pick from under the dash without removing anything, or at least only the vent ducts or some wires. But I don´t know if it can be pryed out easily, and even more important how to press it back in after lubricating the speedometer.
It looks doable but there´s the risk of loosing the plug or not being able to reinstall it.

I think this would be my second go if the new cable doens´t change things.
I have small hands and am still flexible enough to work under there in this tight spot.
If it can´t be done the cluster has to come out anyway.

[Lexi]

I seem to recall on the '56 you have to first remove the rear outer shell, to gain access to it, But memory on this stuff is failing...  Clay/Lexi

[Cadman-iac]

I seem to recall on the '56 you have to first remove the rear outer shell, to gain access to it, But memory on this stuff is failing...  Clay/Lexi

 Exactly my problem. I've done it, but it's been long enough that remembering details is iffy.
 That's why I'll take one apart again later to refresh my memory and assist Hillbillycat with his if I can.
 Getting old sucks!
But hey, one advantage of alzhiemers is that you don't remember watching the movie that repeatedly shows on HBO, so it's always like watching a new movie each time, LOL!!

 Rick

[Lexi]

But hey, one advantage of alzhiemers is that you don't remember watching the movie that repeatedly shows on HBO, so it's always like watching a new movie each time, LOL!!

 Rick

Also, just think of all the new friends you will make each day... Clay/Lexi

Note: Going to look at one of my spares and check this out. Contemplating tearing into mine soon.

[Cadman-iac]

  That's cool. If you run into any problems, let me know and I'll try and help out if I can.
 You know, I do make new friends every day. I just can't remember if I have any old friends.
 
 Rick

[Lexi]

Rick? Rick who? Who are you? Clay/Lexi