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1941 Buick Speedometer Removal

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Opened up the other 2 gauges and cleaned them up inside. Cleaned out the decomposed plastic pieces. Got the new speedometer in and cable attached, lights hooked up. When everything was dangling like this I thought I'd take it for a test spin to see if the speedometer worked...it worked, got it up to 20 MPH and then noticed my foot was getting covered with oil. Oops! Better wait until I hook up the oil line to the oil pressure gauge next time. But now I know the speedometer works!!



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Guess it depends on the internal calibration of the new speedo. My tires aren't that different. I got 205/70/16 the original called for 6.5/16 and the total tire height is within an inch of each other. Just saying. But I plan to do some highway speed tests to find out how accurate it is, and hope the error is small.

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I think the 110 MPH speedometer which was unique to 1940 and totally different from 1939, was actually used for only part of the 1940 run and was changed to the 120 MPH model (1941-1947) during the model year 1940, I've seen some 1940s with it. So I think it will be accurate.
The difference for me is, my old speedometer would go up to 32 and the needle would get stuck on deteriorated plastic grounding it. So I never knew how fast I was going. This new one goes to 120. I will have to see if I can bury that needle past 120 like I did in my mother's 1971 Plymouth Fury station wagon with a 440 and a 6 pack, when I was 19 back when when gas was $0.33 and cars got 3 gallons per mile.
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Hey I just took a second look. Check out the space between the 0 and 110 on both faces. It's the same! They just changed the face to go up to 120 by adding more numbers without changing the space between the numbers. They just extended the scale a little bit more to go up to 120. And by adding the 120 they ran out of room to put the words "BRIGHT LIGHTS" so they moved them to the top. So the calibration inside the speedo is probably exactly the same! Take a look:



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One good thing happened that was unexpected. My oil pressure gauge never worked before. When I was working on the gauges yesterday I absent-mindedly test drove the car with the oil tube disconnected, and oil got all over my foot and the mat and made a big mess, but it must have cleared out some gunk in the line because now the oil pressure gauge works!!!!!!!!!!!

  • Haha 1
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The new speedomoter worked for a few days and then started making noise and the needle started to jiggle. It got worse and worse until it was jumping to 120 at times. Then it got even worse, finally it just went to 120 and stayed there jiggling and making noise. I had to disconnect the speedometer cable.


How do you lubricate these things?

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Sounds like the speedo cable. Since you have already put the dash back together, go underneath and unhook at the trans. Carefully pull the inner cable out (it's pretty stiff so it comes out easy) and make sure no kinks. If it has them time for a new one, I think Bob's has them. Anyhow, when reinserting don't overdo the lube or it can go up into the speedo. Use a small blob about the size of your thumbnail and lightly coat the cable as you reinsert.


Cheers, Dave

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I fixed it!!


I got an aerosol can of graphite that locksmiths use, it's graphite powder mixed with a volatile propellant in a can, the propellant causes the graphite to penetrate into tiny cracks, and then evaporated in about 5 seconds, and I also got a tube of dry powdered graphite. You can get both of these at the hardware store in the padlock section. I crawled under the dash and found the cable connector at the back of the speedo. I spun it counter clockwise and it squeaked, then I generously shot it with the can of graphite spray, and after two spins the squeak was gone. Not leaving well enough alone, I did it 4 or 5 more times to get an extra amount of graphite in there, and gave it a minute or 2 for all the propellant to dry. Then I opened the tube of dry graphite and sprayed a few dustings into the middle of the shaft where the cable goes, and the outside where the spinning part meets the cable connecting housing part. I think that's where the squeak was coming from. Then I found the cable and gave a generous dose of powder, basically filled the connector with it. Connected the cable and voi la.


So this job was very productive:


1. Have a speedo that goes past 32

2. Looks brand new

3. Oil gauge works

4. Top speed of car is 120 instead of 110 in case I need to run moonshine


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My theory is that the squeak was more from some sort of sticky residue on the metal surfaces, resulting from decades of desiccation of the original lubricant. The graphite did lubricate but did not dissolve the old residue. Therefore the Vaseline and WD-40 were needed. The graphite mixed with the Vaseline, the combination of which was Thomas Edison's favorite lubricant. Unlike grease, Vaseline never dries out over time.

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  • 9 months later...

This thread and a couple others have been very helpful to me

with the removal of the instrument panel in my 1941 Buick.


I wrote a blog post that may be helpful to someone who has

to do the same job. Just click on the link above to arrive there.

A couple other related threads that may be useful:

Removing the trip odometer knob

Removing the fresh air vent


Thanks to all the good folks who participate in this forum!


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My Pleasure, Neil.


Today I removed the ammeter/water temp. gauge from the  car.

I needed to remove the wiper vacuum hose to get the end of the temp. sensor

through the firewall. I also had to remove the grommet in the firewall. That just

fell apart. I took the gauge cluster apart by uncramping the bezel that goes

around the glass front. Then I replaced both meters with NOS units.

I still have the old water temp. sensor stuck in the block. I will  be draining

the radiator soon and begin work on that. Next is the speedometer. I need

to put in a new cable. 


When all that stuff is done I need to either close it up or buy an entire

new front end wire harness and go for broke. At present I am inclined to

put in a new harness. If I don't do it now I will be taking this stuff apart

all over again in the future. I attached a couple of photos.


1 Gauge cluster with bezel removed and water temp. gauge removed - note plastic turn signal

bulb mask which is repeated matches front of gauge. I had to re-glue this in place on its cardboard perch

2 Close up of ammeter showing needle stuck due to warped plastic

3 Gauge reassembled






ammeter face removed 2.JPG

ammeter warped 2.JPG

Ammeter and Water Temp new 2.JPG

Edited by Roadmaster71
added text (see edit history)
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Hi Ken:


You are blazing a trail for me as I will eventually be doing the same project, including a new front harness.


A few comments:


(1) Have you seen Dave's excellent thread on rebuilding the instruments in his '40 Coupe?  If not, you should take a look at it.


And (2) did you know that Skip Boyer makes very nice reproductions of all the cream-colored plastic pieces in the gauges?  Your reconstructed gauge would look even nicer with a new "bowtie" piece, and Skip's prices are very reasonable.  If you PM me with your email address, I will send you a pdf of Skip's current price list.



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Neil ....I read the speedometer thread quite a while ago. Just now I went out in the garage

and disconnected the speedometer cable from the dash end. My plan was to next go

back and study Dave's thread. We are thinking alike!


I have bought some really nice stuff from Skip Boyer before. I contacted him a few months

ago and he said that production was suspended for a couple of months due to

recent deaths in the family. He asked me to contact him again in 3 months or so

when he hopes to resume production (one at a time). I will do that. I need a bunch

of stuff.

I may have the current price list ... don't know... will PM you if I can figure out how.

Love this board ... just not sure on PM.

Thanks again.

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  • 3 months later...

I have rewired my car including everything behind the dash and at the time I noticed that the speedometer cable is missing, so I bought one through CARS. I should have take care of this when the dash was apart, but that ship has sailed. Could some one tell me where the cable connects to the transmission? I have a 1940 Buick.




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10 minutes ago, kingrudy said:

I have rewired my car including everything behind the dash and at the time I noticed that the speedometer cable is missing, so I bought one through CARS. I should have take care of this when the dash was apart, but that ship has sailed. Could some one tell me where the cable connects to the transmission? I have a 1940 Buick.




Mike, I know where it attaches on the 1941. It may be the same for the 1940.


You have to get under the car on the driver's side. Then get yourself right under

the side  of the transmission. I had to put the car on jack stands because I could not

fit my body close enough to see or feel anything. Follow the speedometer cable

with your hand. I think it goes almost to the top (floor pan side) of the transmission.

You will be able to feel the connector with your hand. Unscrew it by hand or if 

you cannot go at it gently with an adjustable wrench. It should release easily if your

transmission leaks as much as mine does. In the photos I have attached you will see

the place where it connected after I removed the cable (cable in foreground in one photo).


In some older cars there was a trap door in the floor pan that was used to access this.

Not in the '41.


Note: The cable I bought from CARS was a bit too long. I mounted the curve on the driver's fender

to take up the slack. The speedometer didn't work so well. I moved it back to the original

clamp on the steering column and after some 100 miles or so it is working pretty good up to

60 mph.



41 speedometer to trans 01.JPG

41 speedometer to trans 02.JPG

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  • 2 weeks later...

Some of my posts on this thread and additional details are now in a blog

post I put on our region website. It includes removing the speedometer,

installing the speedometer cable, breaking the ammeter and repairing another,

and getting ready for a new wiring harness.

If you are interested please visit the Westerly-Pawcatuck Region website for the short blog post

and photos.

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  • 2 years later...

Hi all, I'm the new owner of a '41 Super. Thanks to this thread, I have my gauge panel loose, the speedo cable disconnected from the back of the head and I would like to lightly lubricate the inner cable (core). It seems like it may not come out in this direction and I do not want to break anything. Can anyone tell me if it should come out in the direction and I just need to pull a bit harder or should I actually be under the car at the transmission side?

Thanks, Ivor

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It should come out from the speedometer end but you probably need the other end unscrewed from the transmission.

REMEMBER when you lube it only lube the bottom third.  If you over lube it or lube it all the way your lubricant may migrate into the speedo head and you do not want that.

Edited by Tinindian (see edit history)
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