Author Topic: 1957 CDV Speedometer Cable Replacement  (Read 507 times)

Offline My57CDV

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1957 CDV Speedometer Cable Replacement
« on: May 31, 2017, 11:52:38 PM »
I believe my Speedometer cable has broken.  Can anyone provide the Best Specific Details for replacing the cable?
I've replaced some light bulbs on the instrument panel and have partially removed the panel/cluster from the dash .. disconnecting the speedometer cable and then reattaching .. but now to replace the whole cable .. needing some expert guidance ..

Thanks in Advance!

Mark

Offline chrisntam

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Re: 1957 CDV Speedometer Cable Replacement
« Reply #1 on: June 02, 2017, 04:45:48 PM »
Hopefully, someone with a '57 will chime in and lend some guidence.

Have you a shop manual?  That, other than nearby club members, is your best friend!   ;)

I'd disconnect it from the transmission, hook the end to a drill, spin it and see what happens.  That will eliminate a problem in the transmission.  (We'd need some help to determine if the cable spins clockwise or counterclockwise though).

The problem is either the cable, the gears in the transmission (not likely) or the speedo head (possible, but not likely).

Is a replacement cable available?

Let me know when you want to look at it, I'll swing by and assist.  I have to work this Sat, but maybe Sunday?  Do you a floor jack?  That may not be needed, depending on how much room there is to work under the car.  Can you see up under the dash?  I had a '55 Chevy and IIRC, it was the "ol' reach under/around" to disconnect the cable, but the chev was a lot more basic than your car.

If you don't have a shop manual, I highly recommend it.  I have 3 for my '70, one in the garage, one in the bathroom and one by the bed so I can read just before I go to sleep.   ;D

It'll take 30 minutes to an hour to get an initial idea of what we'll need and possibly a diagnosis, just let me know.  I can bring a jack, stands and most all of what may be needed.....

By the way, I spotted that car of yours a mile away last Monday.  It looked good as always.  I was fortunate (for once) not to have mine parked next to yours!   ;D

I would be interested in a heads up as to how to disconnect it from the speedo head - I know its a screw in, but does the cluster have to be removed or is it accessable from under/behind?

I searched some other posts, Bill that has a '57 said, "Take down the air duck under the steering  wheel ,locate the speedometer cable coming out of the fire wall and follow that up with your hand to where it screws into the instrument cluster . Disconnect the the cable ."

As always, sounds easy, but it may not be.....

« Last Edit: June 02, 2017, 04:53:24 PM by chrisntam »
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Offline Walter Youshock

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Re: 1957 CDV Speedometer Cable Replacement
« Reply #2 on: June 02, 2017, 05:12:50 PM »
2 options--first, try to find a universal Delco replacement cable.  It comes longer than the original 1957 cable and can be cut to length.  It comes with a plastic tip you epoxy on the speedometer end.  Not too difficult because you keep your original casing in place.

Option 2 is replace the cable AND casing which requires tearing the dash apart.

Exactly what is wrong with your cable?  It may be that the speedo needs to be cleaned and oiled.
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Offline chrisntam

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Re: 1957 CDV Speedometer Cable Replacement
« Reply #3 on: June 02, 2017, 05:40:15 PM »
The speedometer stopped working.  Don't know why.  We need to do a recon mission....

Can the inner cable be replaced with the cable housing still in place?
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Offline Walter Youshock

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Re: 1957 CDV Speedometer Cable Replacement
« Reply #4 on: June 02, 2017, 06:12:36 PM »
Yes.  That is option 1.  My speedometer froze and the cable actually broke.  Had to remove the cluster to get to the top piece of the cable and then had to disconnect the housing at the trans to get the other piece of cable out.  Reattached the trans end, cut the replacement cable to length, put the end on and that was it.  Part # 6477499.  There's a few on ebay now.

If your speedometer is frozen, you'll keep breaking cables.
« Last Edit: June 02, 2017, 06:33:55 PM by Walter Youshock »
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Offline chrisntam

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Re: 1957 CDV Speedometer Cable Replacement
« Reply #5 on: June 02, 2017, 06:47:32 PM »
How do you know you have the right length (inner cable) when the cable housing is in place?  I assume you'd measure the old inner cable (removed from the housing) and cut the new one to that length?  Then insert the inner cable from below?

How can you tell if the speedo itself is frozen (without breaking the replacement cable)?

Is it difficult to remove the cable from the car? 

Can the speedo be cleaned and oiled by regular folk or is that best left to a professional?

Am I hijacking the op's thread?   ;)
« Last Edit: June 02, 2017, 06:49:50 PM by chrisntam »
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Offline My57CDV

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Re: 1957 CDV Speedometer Cable Replacement
« Reply #6 on: June 03, 2017, 12:00:28 AM »
Thanks Chris & Walter for the replies!
The speedometer has always worked ...until the day it broke ... just prior to this, I began hearing a grinding sound and then the speedometer needle became irratic (driving at a constant speed of 35 - 40 mph, the needle began bouncing) the grinding louder and then a break sound and the speedometer needle dropped to 0.
A few weeks prior to this event, I had pulled the instrument cluster unit out enough to replace the right turn signal bulb (I disconnected the speedo cable and the trip reset from the lower dash). Upon re-installing the cluster, speedo cable to the unit .. I did neglect to reconnect the trip reset piece to the lower dash ... I am speculating this may have initiated the failure.

More details.

Offline Walter Youshock

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Re: 1957 CDV Speedometer Cable Replacement
« Reply #7 on: June 03, 2017, 05:50:39 AM »
May have had something to do with it.  You may have to open up the cluster and check that the gears are ok.  There is a nylon worm gear that usually gets sacrificed.  I was on the turnpike when mine went and it did the same thing--needle bounced, it went to 120 and then 0 and the noise.  It was a stuck speedometer jewel that caused mine to go.

You can reoil the jewel easily.  There's a small brass plug near the threaded portion where the cable screws into the cluster.  Remove that and the cotton inside, soak the cotton in lacquer thinner to get rid of the old oil, let it dry and reoil with a 3 in 1 type oil.  Then test it with a drill set in reverse.  If that doesn't free it up then the problem is deeper in the cluster...
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Offline My57CDV

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Re: 1957 CDV Speedometer Cable Replacement
« Reply #8 on: June 03, 2017, 12:42:50 PM »
Thanks Walter!  I'll investigate that more based on your comments.

Offline The Tassie Devil(le)

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Re: 1957 CDV Speedometer Cable Replacement
« Reply #9 on: June 04, 2017, 02:25:12 AM »
Forgetting to connect up the trip re-set won't have any effect on the operation of the speedo.

The needle flopping all over the place is an indication of a failing inner speedo cable.   As in a broken wire, and this catching on the outer cable, and twisting and releasing the inner cable as the loose strand catches and releases.

After checking the trans end, and the cable, it could be that you have to internally check the head.

Bruce. >:D
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Offline chrisntam

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Re: 1957 CDV Speedometer Cable Replacement
« Reply #10 on: June 04, 2017, 09:09:40 AM »
What is the best (easiest) way to diagnose what failed?  Sounds like diagnosis is needed, rather than just blindly replacing parts.

1)  Pull the inner cable out, check to see if broken, if broken, replace it, spin it with a drill and test it and the speedo head?  Are we pretty confident the cable spins counterclockwise?

2)  Pull the cluster & cable, open them up and look?

It sounds like the cluster is a PITA to take out, but I don't know.....

Any additional thoughts?
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Offline 35-709

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Re: 1957 CDV Speedometer Cable Replacement
« Reply #11 on: June 04, 2017, 10:58:43 AM »
#1 --- this is the normal progression, do the easy things first that you will have to do anyway.   If nothing else you will want to lubricate the inner cable (I use white lube, NAPA will have a good speedo cable lube).  Disconnect the cable housing at both ends, pull the cable out at the speedometer end.  If it is broken it will be immediately obvious and you will then have to pull the rest of it out the other end of the cable housing.  Have plenty of rags handy, it could get messy and mark the carpet or upholstery if that old cable touches something.  If not broken I would inspect it carefully with the thought of replacing it anyway, universal cables that you shorten yourself to the correct length should be available at NAPA and others.

Before replacing the cable, I make it a practice to flush the cable housing with something like Brakekleen (use the straw) to help flush out old, grungy, useless lube that has usually been in there for many years --- maybe since the car was new, then blow it out with an air gun.  Again, protect the car's interior with plenty of rags, it could get messy, or, if you feel up to it, remove the cable housing, although it is not necessary.

My personal opinion is there is a problem in the speedo head, even if (and especially if) the cable is not broken, but this will soon be discovered once you lube and replace the cable (new or old) and spin the cable with a drill motor at the tranny end.  Counter-clockwise --- but if you spin it the wrong way it won't hurt anything --- think of when the car is in reverse.  No worky spinning it either way??  Next is pull the speedo.   ;D   
« Last Edit: June 04, 2017, 11:55:42 AM by 35-709 »
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Offline 35-709

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Re: 1957 CDV Speedometer Cable Replacement
« Reply #12 on: June 04, 2017, 11:53:11 AM »
"How can you tell if the speedo itself is frozen (without breaking the replacement cable)?"

When you replace the cable and hook it back up to the speedo, try turning the transmission end of the cable by hand, it should turn fairly easily.  If not, don't force it.
« Last Edit: June 04, 2017, 11:59:14 AM by 35-709 »
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Offline Walter Youshock

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Re: 1957 CDV Speedometer Cable Replacement
« Reply #13 on: June 04, 2017, 01:49:16 PM »
Remove the cluster.  Pull the cable out of the casing.  If it comes out in one piece and isn't frayed then...

60 years without fresh oiling and this is what happens.
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Offline My57CDV

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Re: 1957 CDV Speedometer Cable Replacement
« Reply #14 on: June 06, 2017, 11:31:08 PM »
Thanks for the advise, comments and directions .. hoping to know more this weekend.

Offline My57CDV

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Re: 1957 CDV Speedometer Cable Replacement
« Reply #15 on: June 12, 2017, 09:59:08 PM »
UPDATE:
Saturday, disconnected both ends of the Speedometer cable .. found it broken at the Transmission end.
Pulled the cable thru the housing .. installed a replacement cable. Turned the cable at the tranny end and
it turned easy in the housing ... next I inserted the cable into the Speedometer, Chris used a drill to turn the
other end at the transmission .. no cable movement at the Speedometer.

I talked with Bill @ Bill's Speedometer Shop in Sydney, OH this am .. described all the above to him ..
His diagnosis was the speedometer is bound up and needs to be serviced.

Comments? 

Thanks! 
Mark

 

Offline The Tassie Devil(le)

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Re: 1957 CDV Speedometer Cable Replacement
« Reply #16 on: June 12, 2017, 10:05:08 PM »
Does the odometer turn when Chris turns the speedo cable from down below?

The Odometer is the only part of the speedo that is directly linked to the speedo cable, as the speedo needle is only operated by a magnetic force within the speedo head.

Bruce. >:D
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Offline chrisntam

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Re: 1957 CDV Speedometer Cable Replacement
« Reply #17 on: June 13, 2017, 05:31:58 PM »
The cable would easily spin (in the housing) when not inserted in the back of the speedo.  The cable would not turn at all when it was inserted into the speedo.  I tried it by hand and with a cordless drill.  There was about 18 inches of inner cable (unsupported by the cable housing) outside the exterior housing while we tried spinning it.  The interior cable started to wind up in a curl (the interior cable that was outside the housing) before it would spin the speedo or odo.

Will the speedo and odo spin while twisting the cable by hand?  I don't know how much force is needed to overcome the friction in the speedo head.

I can disconect the cable leading to the speedo on my '70, try to spin it by hand...would the two speedos be similar enough to test speedo friction and apply what I find on the '70 to the '57?
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Offline Walter Youshock

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Re: 1957 CDV Speedometer Cable Replacement
« Reply #18 on: June 13, 2017, 05:46:41 PM »
There should be no resistance in the speedo at all.  Chances are, the jewel is bone dry or there is a stripped nylon gear inside.  Yours did exactly what mine did.
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Offline My57CDV

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Re: 1957 CDV Speedometer Cable Replacement
« Reply #19 on: June 17, 2017, 11:32:10 AM »
Thanks!  I believe you are correct Walter ...
Pulling Cluster out now and sending to Bob's Speedometer Repair Monday.

Appreciate Everyone's experience and advise!

Mark