The Stovebolt Site Forums The Shop Area Interiors 1946 Speedometer and Speedo Cable Questions

My truck sits on a '41-'46 chassis and has a 3 speed transmission, part number, 591194. My speedometer cable seems to work okay when I just tested it with the speedometer on the workbench. The housing has some moderate kinks in it and I was thinking of proactively replacing it. BUT, I see all sorts of prices for cable/housing setups that claim to fit these trucks.

I am looking for function, and not trying to pass for original.

So, can anyone tell me a source/part number for a reasonably priced cable/housing combo?

ALSO, I think that I saw a thread on how to disassemble and clean up the instrument cluster on these '40-'46 trucks, but I have not been able to find it again. (I know that there are threads or tips on other series of instruments, but I am hoping that I am correct that there is one on this series.)

Thanks!

Nick - Least expensive (not considering shipping costs) I found for a suitable new speedo cable is this Generic 1939-72 replacement unit from Classic.

The only Tech Tip I can currently quickly see if this Art Deco Speedometer Rebuild Legacy tech Tip, but I don't think that answers your question.

Hopefully another Bolter will chime in with what they've done on their truck.

Thanks Dan!

Just a FYI Speedo story

My 46 (w/T5) Speedo started squealing like a stuck pig and needle jumping wildly, I disconnected the Speedo cable from back of Speedo on the side of the road and all went quiet… well…. Must be this old Speedo since cable is now rotating fine and quiet… I sure don’t want to go there, the thought of getting under dash /pull Speedo/send it out/waiting/back under dash to reinstall… so a month later I replaced cable with generic from my local NAPA just because it is a cheap quick way to confirm or eliminate that potential cause… WOW, All working and job done…got off easy on that…

Fast forward 2 years Speedo jumping and squealing AGAIN…. Thinking it’s the Speedo for sure now I was chatting with my older bro (navy diesel mechanic in Nam) he suggested to just relube of the cable first. I figured nothing to loose why not give it a go, pulled cable out of housing from Speedo end, cleaned it meticulously with solvent then brake cleaner and then used a dry Speedo cable lube, dont recall brand but seemed like a graphite type of product again from NAPA. Reinstalled and six months now all is still working good as ever. Didn’t even have to get under the truck this time…
Point is… bench testing is a good start but any compromise is the cable like minor kinks etc do matter, it’s cheap, just R&R it. And thoroughly clean and lube the cable, you might also be saved from going down the Speedo rebuild worm hole.
Chuck

Thanks, Chuck!

Perhaps I will take my existing cable to the local FLAPS and see if they have something that replace it.

The reason I am considering taking the speedometer apart is to clean out flakes of rust and stuff that have collected behind the glass. It won't look new, but it wouldn't look as bad as it does now. Part of me says I should leave it 'till the truck is operable, but another part says, it is on the workbench now, take care of it now! (Then again, there is another part of me that says you have not broken it yet, why risk it?)

Well, one would think that at my age, I would be mature enough when I ask for advice to wait for an answer before I proceeded...Nope!

I did succeed in getting the speedometer apart without breaking anything (so far).

Now, I am asking how to clean things up without damaging the finishes further than nature already has.

Perhaps someday I will want to really restore the speedometer, but at this point having it and the gauges functional and not too awful looking is the goal.

I believe that I may have to paint the chrome bezel that surrounds the cluster, as it is significantly discolored. I wonder if there was water leaking down the dash into the cluster - perhaps in a different truck than mine, as I don't see any evidence on the dash otherwise.

Anyway, if you have knowledge (or a good guess) as to how to clean this unit up without erasing the paint. Will the paint on the backside of the glass come off when I try to clean the glass?

I am not too worried about continuing rust, as we are pretty dry here, but if there is something I can do that would make things look better and would stabilize the rusted areas I should probably take that step.

My speedometer gauges were in decent shape. Someone posted that touching the lettering on the glass may cause them to flake off, so I didn't touch them. I did add some new paint and cleaned the outside of the glass before re-assembling.

Nick - Just a little different track thought process than trying to restore what you have offered here, considering how much you have going on from the water damaged cluster.

What about going with a restoration kit, like this Classy Chev USA 1941-46 Kit? Looks like it gives you everything but the gauge mounting panel and individual gauges for what looks like a fairly reasonable price.

Or an alternative like this Used '41-'46 unit, for a pretty reasonable price? It looks significantly better condition wise, and would likely save you some angst and hours of effort to give you an original instrument cluster.

John - What "paint" did you use to refresh the gauge mounting panel? I've searched through the old threads and haven't found anything specific that identifies a suitable matching color.

Thanks for the replies!
Due to the unexpected retirement of the household breadwinner (my wife), the budget for getting this project on the road is significantly constrained...

But, as a result of looking at John's results and following Dan's links, I think I have decided on a way forward.

Painting the bezel should be straight forward enough.

The Filling Station has a screen printed glass for that speedometer for $29.95, so that gives me the confidence to proceed carefully, with an attempt to clean the glass that I have.
The Filling Station also has a dash decal set for $14.95 and a bezel gasket for $5.55.

The only hesitation I have now about doing an interim cleanup and reinstall is that the tabs on the bezel don't seem as though they would stand too much more flexing.

The paint on the metal plate that sits behind the glass and in front of the gauges themselves is really shot.

It can't look any worse than it does.

Does anyone know what color it should be? What finish? A source for the paint?

I have some brown gloss finish spray paint that I could use and it certainly wouldn't look any worse than it does, but if I can get close to what the original color/finish was, I would rather go that way.

Nick, That's probably close to the interior color used on the AD series trucks. Jim Carter has THIS, or also the AD interior color (link) that I think is too dark (I got some lightened up for my truck.) It's a semi-gloss slight metallic brown. Since you have to buy a quart, it gets kind of expensive. I have about a pint left over that you could try. Shoot me a PM.

Another option is to take that piece to a paint store and get them to match the spots that are still in good shape.

I went ahead and decided that since a new, silkscreened speedometer glass was less than $30, I would try cleaning the one I have and if it got really messed up, I would purchase a replacement.

My speedometer appears to have been opened up once before, as there was no gasket between bezel and the unit.

I started very carefully with just water and saw that although the white silk-screening would look a little fainter when it was wet, it came back as it dried. But, with just water, the glass didn't really get much cleaner. So I checked with Google to see if it thought that soap would remove the ink. It indicated that it probably wouldn't. So I proceeded to clean the glass plate with some Dawn dish soap and my fingers. (Be careful, the edges of the glass are sharp!)

I think that I got a bit overconfident and rubbed some spots more than I should have, as "Temperature" and "Battery" both look a little worse than I had hoped that they would. I would be less aggressive with "scrubbing" the glass (even though I was only using my fingertips) where the lettering is, if I were to do this again.

It seems that a previous owner got some paint or something on the lower part of the glass and tried to remove it was something abrasive. The dark areas you see on the lower part of the glass (other than some residual rust stains) are probably paint I have not been able to get out of a lot of fine scratches on the outer surface of the glass.

I think you could touch up the faded numbers with nail polish. Take your glass plate to the nail salon. The girls that work there will be thrilled to find the exact color match. I did that with hubcaps and hood emblem for my '66 Toronado. They were tickled pink to help find an exact match.

Too bad about whoever got into it before and scratched up the glass.

Otherwise it cleaned up pretty well, all things considered.

Otto, that's an idea I would never have thought of, but it is a really good one!

Dan, I was actually very surprised to see how well it came out. When I first looked at it, I never thought it would get as clean as it did.

The chrome speedometer bezel cleaned up better than I thought it would.

The faceplate has some rust pitting on it and I am trying to figure out how much it would take to make it look better. The whole thing will never be perfect, but if there is a good way to fill in some of the obvious rust damage that will be within the viewable area, I think I should make an effort. Suggestions appreciated!

I have received some paint from a fellow Stovebolter and will apply that with the Preval Spray System once I have prepared the surface of the faceplate to an acceptable level.

Nick, looks like you've got the rust out of the pits on the faceplate pretty well. I have used JB Weld as filler to smooth out a weld joint, but it's a little hard to sand. I've also used spot putty for small pits. It's a lacquer based product so you can smooth it on, sand and repeat. That'll be a good evening project to fill those pits. Just be sure to use your mantra while working on them. OMMM OMMM.

OMMM Ommm!

Working on getting the faceplate smoothed out and ready for sanding. I put some Bondo brand "Glazing and Spot Putty" on the the faceplate with a coat of primer on it...and the putty turned the primer to glop. Mostly scraped off the putty/primer and sprayed with some sanding primer (First Picture) and it is getting very close to acceptable (I think). Any hints for final prep of primer before the color coat goes on? Lots of places where it is not easy to get the sand paper evenly working with the minor details on the sheet metal. Sand Paper?, Super Fine Steel Wool? Other?

While the most recent coat of primer was drying, I took the gauges out of the mounting case (rear sheet metal) and looked the odometer wheel numbers. I have ordered a decal set to refresh the way the gauges look, but I am wondering if I can just clean up the original numbers in the odometer rather than tackling recovering them. Also, how do I get the speedometer needle off its spindle without screwing something up?

What color should the INSIDE of the REAR of the mounting case be? Mine is mostly an ivory color with some black on it too. Was that the original setup? Was that to benefit the instrument lighting? It is not impossible that someone has been in this speedometer before me, so I can't assume that anything is as it was originally intended.

Nick
My recollection from restoring the instrument cluster on Sparky is that is was the ivory color. I searched through my photos and apparently didn’t capture a photo to prove it. I don’t think color will matter as far as the lighting is concerned since the instruments nest closely around the bezels.

As for abrasive choices, easy does it. Maybe a 0000 steel wool would be best? It might be slow going, but likely prevent deep scratches that would need more effort to repair.

Nick check out the info provided under the paragraph "Careful Disassembly" in the Legacy Tech Tip Speedometer rebuild for GM Art Deco Truck.

It mentions using of a couple of small flat head screwdrivers to lift/pop off the needle from the shaft. Be sure to read the related note from "Grigg" in the yellow box that applies to this process.

Thanks, Lee! I just used some 0000 steel wool on the unit and I think it has done the trick. (I have no real experience painting things where I care much about the final finish...but I am hoping that this effort turns out to be pleasant to look at!)

Dan, perhaps someday, I will remember to check the Tech Tips BEFORE I ask a question! Thanks! The numbers on my odometer look pretty good from what I can see. I am hopeful that I might be able to clean them somehow and not have to use the new numbers that come with the decal kit. I am torn between leaving the mileage showing as 45,837.9 as it is now showing, or setting it to 00,000.0.

FWI, I used an old fork and slipped the tines between the needle and post to gently lift up the needle.

Thanks for that suggestion - old forks I got!

Anyone know what might be best to use to clean the old odometer numbers but not damage them?

Also, recommendations for what type of grease and oil to be used?

Okay...I made some progress and then found that my unit is not assembled the same as Jeff Erickson's in the Tech Tip.

I got as far as getting the needle off and starting disassembly of the odometer - removed the shims and found unexpected components. Got a little further and I am now stumped.

After removing the shims, there was not enough play to shift the odometer shaft the way it is stated in the Tech Tip, "Now the odometer can be removed by sliding that side in, releasing the geared end which can be lifted up and slipped out."

At this point, at the opposite end of the shaft from the gear, there was a brass spring clip which I figured out how to remove...but now keeping the shaft from moving far enough to free up the geared end, there is a brass sleeve on the shaft. There are two "grooves?" on the shaft which may tell someone how the sleeve was installed, or how it should be removed, but I am hesitant to just blunder ahead as I know that I would rather live with an old looking odometer that works, rather than one that was destroyed during disassembly.

I have taken photos to try to show the unexpected items.

Any suggestions about what I am looking at and how to proceed would be very welcome!

(Still wondering what grease and oil options to go with during reassembly.)

Those sure are some nice clear photos.

But I have no idea how to help you

Thanks, Otto.

I figured that without some clear photos of what I am facing, it would be a real challenge to get someone who might have faced this before to make some suggestions.

The photos are from an iPhone 14 with some additional light and the flash set to on.

Nick
Here are some photos from Sparky’s speedo restoration.

Full disclosure: It did get rebuilt successfully and seemed to bench test pass. But, in checking the on the road speed showing on the speedo compared to a speed test using an iPhone GPS app it was off. So, it sent off to a vendor listed in the VCCA classified ad section. He did a recalibration for a nominal fee.

I used a lithium base lubricant when the gears etc were reassembled. The numbers on the wheeled gears were so deteriorated they were replaced with a tape sold for the purpose by, I think “The Filling Station” parts vendor.

The photos:
One shows a pencil pointing to a brass clip. Removing the clip frees up the rod holding all the numbered wheeled gears. I recall taking special care to make sure photos and register marks were made on each gear as it was removed from the shaft. I don’t know if that was necessary, but figured it couldn’t hurt?

Yay! Thanks Lee (Sparky)!

I guess my unit really needs a cleaning! After removing the brass clip, I had tried to push that shaft back toward the gear side and it didn't want to budge at all, so I figured that since my unit looked different than the one in the Tech Tip, it must come apart in a different fashion. But, after looking at your post, I went back out to the garage and with a bit more conviction than I had before, I convinced that shaft to slide toward the gear end!

I am definitely getting further into this speedometer than I had intended, but if it works when I am done, it will look so much better that it will be a victory.

I have ordered a decal set that includes the odometer wheel numbers, but, being lazy and a bit intimidated by the prospect of taking the odometer apart, I had hoped that I wouldn't need them.

Thanks for getting me un-stumped!

Well I got all the way into the unit, cleaned things up, got the decals on, got the faceplate painted and when I went to do final reassembly, I found two things...

1. When I use my drill motor to spin the input to the speedometer one way, the needle doesn't move at all...if I spin it the other way - it moves downward...the wrong direction! What is going on? I can't figure out how I might have assembled things incorrectly. They seem to have only one way to go together. I am spinning the input cable clockwise when seen from the rear of the speedo and the needle goes downward. If I spin it counterclockwise, it doesn't move.

2. The Filling Station sent me the incorrect gauge cluster glass! Things are not in the correct places and the glass has significantly radiused corners. It will not work with the bezel on this unit.

Shucks!

I hope that someone who has worked with these units before will tell me what I have done wrong. I did disassemble the unit all the way, but didn't allow the needle driveshaft to drop out of its position - I held it in place with a piece of tape, as was suggested in the Tech Tip. I cleaned a lot of very stiff old lubricant out of the unit which was making movement very stiff. It now turns very easily...just in the wrong direction?!?

Any hints as to what might be wrong would be greatly appreciated!

I am attaching a photo of the unit with my original glass just sitting in place. I had ordered the replacement glass because I was not excited about the issues that exist with the old glass.

Nick
Sorry, I can’t help with this challenge. I wonder if a close comparison between your disassemble sequence photos and current state would help?

I took a good look at the photos I took during disassembly and don't see where I went wrong. (I took a lot of photos!)

I will probably call a VCCA expert next.

It will be interesting to find out the answer...it doesn't see as though it could be too complicated! The components are all pretty simple and seem to be such as they can only be assembled one way. (But, then there is the magic of the magnetic drive!!)

Okay! Now it works!

I contacted the VCCA Tech Advisor for Speedometers and described the symptoms to him.

He responded almost immediately that there is a small pin on the "speedcup" that keeps the needle from moving in the incorrect direction. He said that it is easy to end up with that pin on the wrong side of the tab that is intended to stop it.

I had to disassemble the speedometer again, but since I learned a bit when I took it apart and put it back together the first time, it didn't take long at all to get the pin on the correct side of the tab. (I have attached a couple of photos to make it easier to understand what I am talking about.)

Now the unit works as intended!

I don't have time at the moment, but I intend to update this thread with what I learned about this process that might assist others who face it.

Good job, Nick! Glad you succeeded!

That's fantastic that you found a source to help out and you posted all about it here for fellow Bolters that may need it in the future. YAY

Thanks for the detailed report from start to finish Nick!