Earl

1941 Buick Speedometer Removal

Recommended Posts

Okay, then.  I didn't know about having to remove the windshields.  No way I want to do that.  On my Chrysler, the dash came out pretty easily -- just a row of nuts underneath the windshield garnish molding and a few nuts on each side and that was it.  

 

I'm learning a lot about the differences between GM and Chrysler.  The other thing that surprised me was the fuel gauge sending unit.  On the Chrysler, there was an access hole with a cover in the floor of the trunk.  Remove the cover, and there's the sending unit -- you can have it out of the tank in a few minutes.  On the Buick, looks like you have to drop the whole tank to get to the sending unit, correct?  Getting the fuel gauge working will not be at the top of my list, given what's involved!

 

Great cautionary tale about the alternator replacement.  Ouch!

Share this post


Link to post
Share on other sites

Yeah, I had to replace my sending unit also. Dropping the tank was actually quite easy, used my small floor jack and some 2x4s and a friend to help balance it as I lowered it. Only took about 30 mins. I had the tank Renu'd  then as well. Make sure to run a ground wire from the sending unit to the frame, if the ground is bad the gauge will always read full (or if there is an open in the wiring or sending unit).

 

Cheers, Dave

  • Like 2

Share this post


Link to post
Share on other sites
34 minutes ago, Daves1940Buick56S said:

Yeah, I had to replace my sending unit also. Dropping the tank was actually quite easy, used my small floor jack and some 2x4s and a friend to help balance it as I lowered it. Only took about 30 mins. I had the tank Renu'd  then as well. Make sure to run a ground wire from the sending unit to the frame, if the ground is bad the gauge will always read full (or if there is an open in the wiring or sending unit).

 

Cheers, Dave

 

That's good news that it didn't turn out to be that big a job.  I was already thinking it would be a good excuse to have the tank reconditioned and replace the rusty straps.  As you said before, the 4 most expensive words for old car people: "While I'm in there..." :lol:

Edited by neil morse (see edit history)

Share this post


Link to post
Share on other sites

I just started reading through this thread, and of course lots of good advice from folks.

I restored a '41 Roadmaster a few years ago and I bought a complete new harness from Harnesses Unlimited, and though it was not cheap, the instructions were good, the look and fit was perfect.

 Thing is, if you just cut out the bad parts, then the rest is still old, and it will almost for sure give you troubles over time, as the rest of insulation ages out. I replaced all of mine with the seats out but the dashboard in, and the instrument panel pulled out as described earlier.  I would think that it would be worth your while to replace it all, at least the front part, which is like 80% of the wiring.

 Keith

Edited by Buicknutty (see edit history)

Share this post


Link to post
Share on other sites

Hi Keith:

 

Thanks for your advice.  Harnesses Unlimited was actually the first place I found online, and I was wondering if they would be a good choice.  The more I think about it, the more I am inclined to just go ahead and do it right.  I am happy to hear that it is practical to put a new "front" harness in without removing the whole dashboard.

Share this post


Link to post
Share on other sites

I did all you want to do on my 42 Buick.  If you remove the radio  and  glove box also, this will give you more access.  The front seat just pops up, you do not have to remove the frame and back to give you more room to work. Make sure you get the wiring diagram for your car.  As soon as you start taking the old wiring out it will crumble. Make sure you mark every wire end  and  take plenty of pics  and  when you think you took enough   ......   take more. 

  • Like 1

Share this post


Link to post
Share on other sites

I'm replacing the speedometer on my 1940 now. The old one as well as the temp and fuel gauges have the corroded plastic like in Neil Morse's pic above. The speedometer works up to 32 MPH and then bumps into some deteriorated plastic, and the odometer doesn't work. The whole thing has de-centered itself and has to go. Luckily I found a mint one on ebay: http://www.ebay.com/itm/1941-Buick-Dash-Cluster-Gauges-Speedometer-Nice/232298931911?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

 

Don't know how it compares to a 1941 but my 1940 has 6 studs with 3/8 nuts on the back of the cluster panel. Two on the extreme right edge can be seen with a flashlight and they are easy to remove. There is one on the far left side in the middle and one above and to the left of the temperature gauge, you have to feel around for those 2 and can't see them. Those 2 you can get with a regular box wrench without disassembling anything. Then the are 2 at the bottom, one on either side of the steering column, you need to remove one of the defroster or heater switches to get to the left one and you need a long socket wrench with extentions. The right one you have to remove the ignition switch assembly to get to it. Even after the 6 nuts are removed you have to pry and jiggle to coax the cluster panel loose.

 

Today I'll try to get the old speedometer out. Guess I'll start by loosening the cable. My 1940 speedometer only goes up to 110 MPH and is slightly different from the one I got on ebay which is the one for the years 1941 to 1947 and it goes up to 120 MPH. Otherwise they are the same.

Share this post


Link to post
Share on other sites

Spent all day trying to get more wiggle room behind the cluster panel. Disconnected the oil line to the oil pressure gauge. Tried to straighten the old wiring harness. The steering column prevented full movement, I had to remove the steering column bracket so the column drops down an inch or two. Extremely difficult to work back there, when you pull the thing towards you it springs back in, from all the wires. Trying to find which wires are the worst and maybe disconnect them.

 

Two of the nuts I had to remove to get the panel loose were extremely hard to get to. Guess I sure as heck won't be putting them back on.

Share this post


Link to post
Share on other sites

Yeah, I did this abt 3 yrs ago, my writeup on it went in as an article in the Bugle. Once you get it out, I wired in "extenders" on all of the lights/gauge wiring to give me some relief on the reinstall. The harness was shot anyway, so I used modern wires/solder/shrink. See

I think the new forum SW has scrambled the original pix locations...

 

Cheers, Dave

  • Like 1

Share this post


Link to post
Share on other sites

I guess from your pics the thing for me to do is remove the 3 nuts holding the speedo to the panel and the 2 nuts each on the other gauges, and the panel comes out and I'll have all the wiggle room I could want. Not going to replace any wires, the old wires are tinned copper which lasts 200 years, or maybe 2000, it's the insulation that has rotted, so I'll just coat any wires with acrylic as needed. I like to use 3 coats. I will have to lengthen the wire going to the "bright lights" sign on the speedo, because the 1940 had it on the bottom and my new 1941-47 speedo has it up top where the wires won't reach.

 

Of course replace all bulbs I come across. They are cheap.

 

I'll take pics and post them here. This is going to be cool.

  • Like 1

Share this post


Link to post
Share on other sites

Notice the old one (right) had 2 bulbs for bright lights....a top one which is a red dot, the bottom one says "BRIGHT LIGHTS"

 

The new one just has one light.

 

Old one made in Rochester, new one Flint.

DSCN1348.JPG

Share this post


Link to post
Share on other sites

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!!

DSCN1354.JPG

DSCN1355.JPG

Share this post


Link to post
Share on other sites

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.

Share this post


Link to post
Share on other sites
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.

Share this post


Link to post
Share on other sites

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:

 

DSCN1351.JPG

Share this post


Link to post
Share on other sites

Done!!!!!!!!! And it works. Took it to the store (a known distance) to test the odometer, and it was accurate!!

DSCN1359.JPG

DSCN1356.JPG

DSCN1357.JPG

Share this post


Link to post
Share on other sites

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

Share this post


Link to post
Share on other sites

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?

Share this post


Link to post
Share on other sites

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

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now