Need 1958 Ford Speedometer Help

Stephen Pellegrino

Junior Member
I have a 1958 Ford Custom 300 w/ a six & automatic. The speedometer reads about 5-15 MPH slow, depending on speed (at faster speeds it's more accurate). Also the needle sticks at 0 until you're going about 30 MPH.

When I got the car it had no speedometer driven gear in the transmission. I bought one from Echler's (described as correct for '57 & up Fordomatic, but I don't think it's right). I have a 3.56 rear axle ratio, and according to the 1958 Ford shop manual, I should have a gear with 22 teeth. Can't find one. Gear photo shown is from an eBay auction I missed out on. Anyone have any suggestions?
 

Attachments

  • image.jpg
    image.jpg
    71.5 KB · Views: 172
  • Screenshot 2022-08-29 at 20-35-19 s-l1600.jpg (JPEG Image 1600 × 1200 pixels) — Scaled (62%).jpg
    Screenshot 2022-08-29 at 20-35-19 s-l1600.jpg (JPEG Image 1600 × 1200 pixels) — Scaled (62%).jpg
    11.3 KB · Views: 18
  • 20220827_200945.jpg
    20220827_200945.jpg
    57.2 KB · Views: 18
  • Screenshot 2023-03-17 at 23-33-09 20170704_124507_resized.jpg (WEBP Image 1200 × 675 pixels).jpg
    Screenshot 2023-03-17 at 23-33-09 20170704_124507_resized.jpg (WEBP Image 1200 × 675 pixels).jpg
    20.4 KB · Views: 12
Since the speedo is sticking, and the error is variable, I’d look at the speedo head first. I’m not familiar with the 58’s, but other speedos have some lube provisions or need cleaning. Hopefully someone will chime in. Much better than not working at all.

As an aside, does the mileage work and appear accurate?

Nice ride. One of Fords best in my book.
 
I suggest you resolve the speedo problem before playing around with new driven gears. That could be the source of your problem.



Do you have any idea of the # of teeth in the gear you have ?


This company repairs speedos - Williamson's Instruments in Arkansas
 
I suggest you resolve the speedo problem before playing around with new driven gears. That could be the source of your problem.
. . .
Check the accuracy of the odometer before changing the driven gear.
Being gear driven the odometer will be more accurate than a speedometer needle driven with magnets & springs. If the odometer indicates very near correctly, a good cleaning, adjustment or light lubrication to the speedometer parts you have may be all it needs.
 
The magnet rotor and drag cup bearings do need some attention after many years of neglect. If it has a proper tooth count driven gear, it should be close but worn or stiff parts can and do affect things depending on condition. The drag cup is connected to the speedometer needle and it relies on the rotating magnet to draw it into correct position.
 
I just had my speedo restored by a guy in Colorado and he did a good job on the whole cluster. The only issue is that the needle got bent just enough that it sticks at 30 mph when sitting still. When I get done wiring I am going to take it out and he will walk me through unbending it. I was happy though with his work.

Mike
 
I just had my speedo restored by a guy in Colorado and he did a good job on the whole cluster. The only issue is that the needle got bent just enough that it sticks at 30 mph when sitting still. When I get done wiring I am going to take it out and he will walk me through unbending it. I was happy though with his work.

Mike


Could be Rusty at Speedometer Service. He repaired the Stewart Warner speedo for my '39 p/u. Also sold me a cable for my '54 Ranch Wagon with an AOD. Good guy to deal with.
Speedometer, Generator And Alternator Repair In Colorado Springs (speedoservice.com)
 
Yep that is him. I called him about mine and he said he would walk me through it or I could send it back to him. Soo far very happy with his service and he tested my fuel/temp gauges as well.
 
Thanks to all for your responses! BTW, it turns out that the fewer teeth the speedometer driven gear has, the higher the speedometer reads!;)

So here's what I did: I wanted to avoid taking the dash apart, so I tried switching out the speedometer driven gear at the trans (attached to end of cable). First I tried a 17 tooth gear, and then the speedo didn't work at all! So then put in an 18, and that made a noticeable improvement. The reading is still slow at 0-15 MPH, about right at 20-45, and a little high at 50-65. Not perfect, but better than it was before. I would say going from 19 teeth to 18 increased the reading about 5-7 MPH average.

I like the fact that this is a responsive board, and that so many people replied to my post!

Here are two more pictures, and a link to a web article featuring my '58 and a '57 Ford:

https://www.curbsideclassic.com/blo...ting-the-most-for-your-money-in-the-late-50s/
 

Attachments

  • 20190827_122524-1_resized.jpg
    20190827_122524-1_resized.jpg
    62.1 KB · Views: 9
  • 20190827_122455_resized.jpg
    20190827_122455_resized.jpg
    54.7 KB · Views: 11
I suggest you resolve the speedo problem before playing around with new driven gears. That could be the source of your problem.



Do you have any idea of the # of teeth in the gear you have ?


This company repairs speedos - Williamson's Instruments in Arkansas
The gear I had in there was 19 teeth.
 
Back
Top