Repair Of Your Imperial's Speedometer

 


Imperial Home Page -> Repair -> Electrical System -> Gauges -> Speedometer


Read Philippe Courant's excellent article on removing and repairing his 1957 Imperial speedometer.


Question from Rickard (1955):

We have just recently purchased our very first Imperial! But when I drove the car the speedometer didn´t work. However, when I look at the speedo I can't even see the needle. Should it not be visible pointing at 0 or does it hide when the car is not moving? There was some noise from the speedo cable but I have had it removed since and lubricated it. I will not have an opportunity to test drive the car for a while now and that's why I'm asking here. Second question: How much do I have to remove to get
the instruments out to change bulbs and possibly also fix the speedometer?

Replies:

From Gary:

There should be a red arrowhead pointing at "0" when the car is at rest.

Fortunately all of my dash lights work, so I haven't been under there to see what all is involved in changing bulbs. One other thing you should know is that there is a small plug like fitting with a felt wick (on the back side of the speedometer) that needs to be removed and oiled periodically with a non congealing oil (a high quality oil such as used in watch and clock repair).This lubricates the speedometer head.

From Paul:

All the bulbs are accessible and can be changed without disassembly.


Question from Randy (1955):

Last night I took my black '55 Imperial out for a drive. The speedometer started fluctuating wildly and a bad noise accompanied it. It sounds like the speedo cable is dry and need lubrication. Excuse my lack of mechanical expertise, but, how does one lubricate a speedometer cable and what type lubrication is recommended?

Replies:

From Rodger:

Lay through the drivers floor board in the best position that you can and reach up from the bottom of the dash to the center of the speedo area. The "nut" that holds the cable is round and about the diameter of a 50 cents piece. Un-screw it and then fish it out to a location that you can pull the inside part of the cable from the housing. Even though you may think so, it is not seven feet long. Clean it and then re-insert it into the housing with a fresh lube.

From Jim:

I highly recommend disconnecting the battery before doing this. That cable gets loose and touches a hot terminal under your dash and it will be grounded. Not a good thing!

From Kerry:

Someone will tell you how to lube the cable but until they do, I'd suggest unscrewing the cable from the back of the speedometer. My '54 did exactly the same thing and I did nothing about it. Within a couple miles, it swung wildly and the the needle popped off. :(


Question from Keith (1958):

Does the speedo come out of the dash of a 58 without having to remove the whole dash? Also have a need for the steel gear from inside the auto pilot, and linkages to the carb from auto pilot. Can some one tell me is the center drive shaft support rubber bonded to the steel mounting bracket? Mine is a good fit on the drive shaft but moves in the bracket.

Reply from Philippe:

It's nearly impossible to remove it without removing the dash! My speedo needs repair but I can't remove it:  the bracket dash (and other things) prevent its remove. But you can try (you will need to remove the wiper motor arms). The center drive shaft rubber must be bonded to the bracket, if it is loose you'll have vibrations and some knocks when you need torque. Mine was ok but i've coated it with windshield bonded material used for today bonded windshield. This glue is very strong and remains flexible.


Question from Charlie (1959):

I need to remove the speedometer on my '59 Imperial and get it reconditioned. The service manual doesn't seem to give instructions on how to remove it. Has anyone on the list done this? Any advice on the best procedure and/or things to watch out for?

Reply from Steve:

Unfortunately I have done it several times. Loosen the two nuts that hold up the steering column and drop the column down. Take a rag and tape it to the column to protect the finish (you will regret it if you donít). Remove the trim from around the instrument panel then you will find screws holding it in. Memory says four of them, but memory isnít what it used to beÖ. You can get it out far enough to loosen the speedometer cable and other connection holding it close to the dash.

The actual speedometer assembly is held in with about 10 small machine screws. Loosen them and remove the assembly. Really it isnít very hard, but it isnít a whole lot of fun either. Just be careful not to pull any of the wiring loose that is connected to the instrument panel.


Question from Tony (1959):

I have a problem with my speedometer in my '59 Imperial. At 30mph, it's okay. At 50, it registers 65 mph!! Obviously, the jewel/s is worn. Who does this type of work IN A TIMELY MANNER?? Does anyone have a KNOWN good one for sale or to use, in case it takes a while to get mine repaired?

Reply from John:

My belief is that this problem is caused by the difference in the sizing of today's tires. EVERY early 60's Imperial I've ever owned showed roughly 15mph over the correct speed when cruising at highway speed.


Question from Mark (1960):

I need to lubricate the speedometer cables (transmission to AutoPilot and AutoPilot to speedometer) on my '60. Also, should the speedometer head be lubricated in any way and, if so, with what type of lubricant.

Reply from Dave:

If your '60 is like a '59, there is a place to lubricate the speedo head. Right where the cable hooks in, - there should be a small "cap". They (the factory) put a little "wick" here with a dab of grease on it. I wish I had known about this before I broke 3 cables and a speedo gear a few years back! By the time I discovered this, - the speedo head was totally seized, and I had to remove the speedo head and get it worked loose again. As for the lube on the cables, - I use plain old wheel bearing grease. Works great, and lasts a long time.


Question from Timothy (1960):

So if a guy got a little over zealous greasing his speedometer cable just before a long trip and then his speedometer started acting weird... Any idea how to fix it?

here's what it is doing: I was cruising down the highway about 3 hours after lubing the speedometer cable in a Napa parking lot (after installing a new brake light switch (Thanks Rick!)).

So I was going 80 and had been for a while. I decided to go 90 for a while and noticed that it took a lot of vroom to get up to 90, but really seemed to stay there too effortlessly. I didn't think much of it 'til I stopped for gas and realized when I got in the car to leave that it was still showing 55MPH on the speedometer at a dead stop.

Since then it is works like this: speedometer will not return lower than 30, ever. above 40 it does generally work but it takes minutes of driving at a speed before the speedometer registers the correct speed, it seems a touch more responsive to increases in speed than to decreases. How do I undo this, it's um not in the FSM. I keep looking for the, "So You Did Something Stupid" chapter in my FSM, but my copy doesn't seem to have one :)

Reply from John:

I don't think your supposed to do that. I think there's a special lubricant that is applied to the cable inside the housing, not at the speedometer. I would think that if grease got inside the speedometer, that's why its not returning, since its workings are extremely delicate.


Question from Greg (1961):

I have had to replace the speedometer cable and the pinion connection at the transmission twice, recently, on my 1961 Imperial. Does anyone have any ideas what may be causing this failure?

Reply from Don:

Your speedometer head is seizing... it has happened to my '65 Crown, also.


Question from Denis (1962):

I have three '62 Imperials, a 2dr, 4dr & LeBaron. The gages light up at night on all of them, except one gas gage, but the spedo light does not work on any of them, so it is difficult to check my speed at night. Does this run off a different circuit than the gages?

Reply from John:

The speedo has an EL panel inside & it has those same very fine wires that break so easily. You will need to remove the whole cluster to open it up & have a look at the situation. This can be a pain to do. If you decide to pull the cluster, be sure to place something, such as heavy tape over the rounded surfaces of the knob housings below the cluster to avoid damage. You should also find there is a very short black wire attached to the cluster that won't allow you to pull the cluster far enough out to disconnect everything else.


Question from Kerry (1962):

My new '62 has an interesting speedometer problem. When you get up to about 65, the traveling band (needle) goes up to about 100 pretty rapidly and stays there until you slow down below 40 or so.

Anyone seen a problem like this?

Replies:

From Dick:

This is a fairly common symptom, caused by wear in the bearing on which the internal spinner turns within the drag cup. When the bearing is worn out and begins to wobble at high speed, it allows actual glancing contact to the drag cup, which will peg the needle. You need a replacement speedometer, Kerry, or else take it to a speedometer repair place and have them go through it.

Sometimes lubrication of this bearing will settle things down for a little while, but the problem will recur, especially in cold weather. You could try some oil in the wick above the cable socket - it might help for a while.

Also make sure the cable is not bent and applying sideways pressure on the back of the speedometer head - this makes the problem worse by stressing the bearing. I've seen them where simply re-routing the cable to avoid any sideways pressure or twist on the cable will calm down a noisy or erratic speedometer - again, for a little while anyway.

From John:

That happened to me on my first Imperial, a '63 back around 1970. The dash lights used to go off sometimes & I would give the top of the dash a couple of slaps & they would come back on. Well, I guess I did that a bit too hard one time & got the condition you describe. They said the problem was the speedometer jewels. At that time, it wasn't a problem to fix. I don't recall what they charged me to make the repair.

From Don:

It sounds like a problem I had and all it needed was lubrication.

From Jerry:

I agree with Dick's suggestion re speedometer shop. I have succeeded short term with graphite lubrication, but ultimately have taken it in to the speedometer shop, always felt like the price was reasonable and the service exceptional. They usually are a little mom n pop operation next to that good fish taco joint. In fact, I once saw Dick Benjamin at the speedometer shop but was in too much awe of the sage that I failed to introduce myself. It absolutely escapes me as to why he was driving a Yugo. It looked like it had been given a frame off restoration, engine purred like a kitten and burped like a puppy. One of the benefits is that they can, and usually as part of their service, will calibrate the speedometer. I used to get accused of speeding, but didn't believe my accusers. One day I came up from behind a police officer and the traffic was moving quite slow, so I passed him and his citizen entourage, much to my dismay-he sped up followed this brazen citizen in a 4-cylinder (typically SLOW) Volvo, and gave me a ticket. He asked if Bernadine Hesch was my Mother, I said yes, he said-"she was my teacher". I still got a ticket! So off to the speedometer shop and taco place went I. Another Volvo story, I had dry rot in one of the tires, I believe I was rotating a spare that may have been original. The car made awful noise at highway speeds, as though the front end was gonna fall right off, and no one at the alignment shop could identify the problem. Finally, the tire blew up. I learned my lesson and always replace when I can see early dry rot-cracking that may be superficial on the wall of the tire. The final Volvo story is I got disabled in a Volvo, (not kidding-lumbar and cervical fusion) I think they should send me a trophy??? or some $$$$, maybe I could do a Scandinavian tour....Well, at least my sick sense of humor was unaffected.

From Paul:

The drum speedometer on the '62 has brass needle bearings on both ends. The speedometer cable drives a magnetic drive wheel which is perpendicular to the pickup wheel on the drum. These units are good for about 120k miles until they need adjustment. What you do is take out the speedometer/instrument cluster by disconnecting the speedometer cable and the clock wire, removing the mounting screws and pulling the assembly out and inverting it on top of the dash. On the left hand side is an access hole covered by tape. Remove the tape and look inside. You will see a stop nut on the drum shaft and an adjustment . The goal is to move the drum a horse hair away from the magnetic drive wheel. This you can do by releasing the stop nut and turning the bearing with a very small wrench, then retightening the stop nut. Success. The speedometer will no longer bounce up to 100, it will be consistent, and it could be accurate if you road test the car and perhaps repeat the process.


Question from Curt (1963):

The speedometer on my recently purchased 63 Crown has never worked.  I have checked the cable and it is connected.  Are these speedometers electrical or mechanically?  My dash lights don't work either. Is this problem related? Fuses look OK.

Replies:

From Mick:

The speedometer is mechanical. The dash lights are electroluminescent and are powered by a power supply that changes the 12 volts DC to over 200 volts AC through a transistor and transformer arrangement.

With the speedometer check that the inter flexible shaft is still in one piece. if not pull the entire speedometer cable and visit your local speedometer shop for a replacement. I paid about $70 for a custom made unit for my Chrysler 300 about 6 months ago.

From Paul:

Here's two possibilities from me:

The reason mine quite was that the nylon drive pinion (gear) in the transmission stripped out so that it no longer turned the cable. The cable is square in shape so if hole in that gear isn't also square, the transmission will turn the gear, but the gear won't turn the cable.

The second one I thought that I would mention is if your car has Auto Pilot, you might check to make sure that all of the cables are properly connected. I had a problem with an Auto Pilot unit that prevented the short cable between it and the speedometer from turning. I took the cable out, cleaned it up and reconnected it and it worked fine.

From David:

Speedo is cable operated and they do have their problems mine was redone by JC Autos of Seattle they specialize in Chrysler 300's but can do Imperials The panel lights they can also do, its probably the power pack BE CAREFUL don't do it with out being sure what you are doing as more damage can be done.


Quesiton from (1965):

The spedometer is not working in my '65 Imperial convertible. The seller told me that it used to, and was 'noisy'. I suspect that the cable was going bad, and finally did. (Happened to me once on a '72 Toyota).

Am I probably right?

Other hints -

Gas guage reads wrong (Not related, I am sure) Tranny has a leak (probably not related, I need to research).

Reply from Kenyon:

The cable should unscrew from the speedo and from the transmission without much effort (I don't know about how easy to access each with your hand though). They are generally not torqued down, but may be sticky with age to break loose.

Assuming that you find where the cable goes into the speedo and transmission, take it out and then inspect both ends of the cable. It acts as a drive-shaft and twisting one end should result in a 1-to-1 rotation at the other end. If it works, your problem lies in either the gear that drives the speedo cable off of the trans or in the internals of the speedo in the dash.

Most larger cities have a place that does instruments/speedo rebuilding. There is one here in San Francisco that can fabricate speedo cables from raw stock, so I'm assuming that you should be able to find similar near you if yours is bad.

Bad speedo: repair or buy used. Bad transmission gear drive: probably replace, but don't know about that firsthand. Your wrenches and service manual or a non-chain trans place would be the places to look on that one.

Chase the transmission leak right away by wiping the trans case with a rag if not obvious. If you really want to, you can dust the cleaned transmission exterior case with talcum powder to spot the leak quicker, but I usually don't bother with that as you can usually tell right off. Don't let an input or output shaft seal go without attention. A full rebuild is not far away if it's one of those. They're cheap seals, and the rear can be done while the transmission is in the car after disconnecting the driveshaft.

The pan gasket is messy to do but not a big deal. The shift cable or shift linkage and speedo seals should not be tough if you can get them and then get access under the car. Short work for a trans shop, too, but expect some sort of minimum charge from them.


Question from Tim (1967):

On my '67, the odometer and trip-meter simultaneously stopped working. The speedometer still works fine though. The knob that resets the trip-meter to "zero zero zero" still works too.

Does that give you brilliant Imperial sleuths enough information to deduce where the problem is? Is there any chance it's something that *doesn't* involve opening up the dash to fix?

Replies:

From John:

Sorry, but you will be going into the dash for this one. The speedo cable comes into the instrument cluster and gears inside transfer the cable rpm's to info such as speed and miles. Since you still get speedo info, the cable is doing its job and the gear(s) that convert rpm's to odometer readout have apparently stripped out or possibly moved enough to loose contact. Yoou will need to go into the speedo assembly or have a speedo shop fix it.

From Dick:

In a word: - - - - - -no.

The failure is in the mechanical gear train that connects the spinning speedometer drive cable to the totalizer wheels. These are plastic gears, and are no doubt worn out.


Question from Tim (1967):

Since I have other repairs to be done behind the dash (that pesky crotchety headlight switch again), I'm going to ask my mechanic to look at the odometer problem while he's in there. What parts should I have ready for him? The parts book and FSM seem to treat the speedometer as a single unit rather than a collection of parts, so am I likely to end up just getting a whole speedometer (somewhere...) for him to swap in? Or are those gears replaceable at any hardware store? I'd rather not have to send the speedometer out for repair, and since parts are usually cheap compared to labor by the hour, I don't mind doing a little predictive part purchasing...

Reply from Dick:

I urge you to have him remove the speedometer as a total unit and send it to a professional for a complete going over. Yes, someone with experience, fine tools and skill can repair or replace the individual parts, but the
skills required are comparable to fixing a clock - I wouldn't attempt it if you are not ready to work on something that delicate. The parts required will only be available to a speedometer professional, and maybe even then you will have to supply a "parts" speedometer. Be sure to indicate what you want him to set the odometer to when he is finished - you can chose to have it spun back to zero, or put in your phone number, or whatever. I always record the reading and set it back to that when finished with the repair.

Be certain you caution the R&R guy about paint scratches on the top of the steering column, and supply him with your shop manual, with the appropriate page indicated, so he doesn't make the same mistakes the rest of us did the first time we pulled one!


Question from Mark (1971):

I have a fuselage era car, and as most of you know, one of the unique things about the fuselage era Imperials is that the speedometer is not protected or shielded by a clear piece of plastic, as it is in most cars. The needle is in a little slot, so to speak, but the numbers themselves are raised plastic letters on the dash itself. As a result they are exposed to the elements and sometimes get dirty.

Well, unfortunately, the previous owner of my car decided to clean off the dash and used something that was a little too strong, maybe Fantastic or something similar, and the result is the white paint (?) on the numerals has completely come off in some places and been smeared in others.

Some time ago I sat down with a #.0008 paintbrush (really small) and a bottle of white paint, and one hour later I had finished painting the "90." Of course, I was completely blind for the rest of the afternoon. The 90 doesn't look too bad, but it's clearly not a factory finish, and very time consuming.

Does anyone know how these letters were painted originally? Is there a way to do it now? I've thought of creating a mask around the letters and spraying them, but I don't know how I'd create such a detailed mask. Any help would be appreciated!

Reply from Elijah:

I think your best bet might be to visit your local hobby store and invest in a paint stick. These things are essentially "magic markers" filled with enamel paint. They come in a variety of common colors. I think the wedge-shaped felt tip of the paint stick would make it easier to paint the raised portion of the speedometer numerals without smearing paint onto the rest of the instrument cluster.


Question from Stan (1981):

Does anyone know where I can locate a speedo sensor? The original number was 0435070 and then replaced by 835507170 Speedo sensor is no longer available nor are there any laying around at any of the Chrysler dealers or partsvioce.com. To try and help, these were used on several Dodge trucks from '89 thru '98 model years and there must be several n wrecking yards. It is no fun drive one of these cars and have the speed read zero the whole time or go to 16 or 17 when at a highway speed. :)

Replies:

From Rolland:

I have one spare but it does not show either number that you listed. Is this the sensor with a male speedometer cable connector at one end and a female cable connector at the other? It is about 2 1/2" long and perhaps 1" in diameter with about a 4" black lead and a two pronged connector.

The number show on the part is 4085919.

From Dick:

This is a very simple device - have you taken it apart to see if you can find the trouble? It is just a coil with a magnet in the middle which is spun by the speedometer cable. If there is electrical continuity between the two wires, it should work. If there is not, you probably have a poor connection to the coil winding. If you can get it apart, you should be able to reconnect the wires.

From Neil:

My speedo plays up occasionally, especially after washing under the hood or working on the car in the rain, a quick squirt of lube sorts it out after it has shown a few miles contempt at my underhood activities.

Just another grumpy Chrysler part that makes up the Imperial.


Question from Bob (1981):

I have repaired almost all of the miscellaneous problems on my '81.  But I still have no speedometer, it just reads 0 all the time.  I replaced the cable from the speedo sensor to the transmission (it was bad) and checked to make sure I got a pulse from the sensor but still no speedometer.  The rest of the digital dash passes the self test O.K.  I can adjust the clock and change the read out from metric to standard the fuel gauge works fine, but no range or odometer change/reset.  If anyone has had this problem and knows where to look please give me a hint.  (I'M TIRED OF TRACING WIRES!)

Reply from Bob:

For your problem, Chrysler says to replace the Electronic Cluster, (even if it has passed all of the "built-in" tests. There is, however, one suggestion - it is - from the manual: disconnect the battery momentarily, reconnect and drive the car for 8 miles. If the problem persists, replace the module.


This page last updated November 12, 2004.  Send us your feedback, and come join the Imperial Mailing List - Online Car Club