Classic/Antique Car Repair/SPEEDOMETER REPAIR
Jack, You said in one of your responses you had about 13 pages of instructions on speedometer repair. I have a stuck one that is a 29 oval. I have teken the oval back plate out to find hardened grease and don't want to go farther without knowledge. Can you please email your repair sheets so I can continue. Thanks, Ron
Sorry I'm so late getting back to you. I'm in South Carolina and don't have the info with me. Not used very often. The 13 pages are too big to e mail as an image, but I can fax them to you when I get back to Mi. (Mid Nov.) I need your fax number. The drive gear is pressed on and has to be pulled off without hurting anything. Then you have to take out the shaft and clean it and lube it. The little pressed in plate has to come off to get to the gears, if I remember correctly. I'll try to get hold of the main page that shows you how and attach it to a future answer to this question. A friend may have a copy I gave him. Good luck. That is a very common problem. They all freeze up sometime. jack
I found this in the web. This way, the shaft does not have to be taken out. Jack
Re: Tips in rebuilding a Model A speedo?
This click will take you to enough information to keep you confused for the rest of your life:
Here, free, is an old scribble of mine on reviving a speedo that isn't badly damaged:
Here's my speedo repair technique: remove bezel and glass, get speedo out of case. Get a tin can or something that allows you to set the speedo down with face up and secure balance, and study how you are going to hold the thing so neither your fingers nor the liquids to be used can touch the face or odometer. That stuff is VERY delicate and easy to destroy.
Near the cable end, on what amounts to the speedo's main bearing, is a tiny brass plug. Get it out--I usually manage to extract them unhurt by threading a tiny machine screw into the cup--and extract the piece of felt within.
I then repeatedly flood this lube well with first kroil then WD40 as it frees up, sometimes liquid wrench if I feel something thinner is needed. You want lots of fluid to go in there and then leak out the bottom to dissolve and wash out the petrified lubricant and crud.
When the shaft will spin freely by finger twirl--you should be able to get 5-10MPH easily by finger--soak several times with carb cleaner and then brake cleaner to remove all those miracle solvents. When drained and dry, I fillerup with Marvel Mystery Oil, based on my scientific observation that the only real speedo tech I ever saw in action used something that sure looked like MMO. Stuff felt&cap back into hole, well soaked. Let drain, reassemble.
The multiple screwdriver tip sets you can get at discount stores contain a Canadian Robertson tip (square) that fits early Ford speedos and allows you to motor them up. You can also do a very rough test based on the supposed RPM of your electric tool, based on the speedo's calibration of 1,000 RPM=60 MPH.
Here's a ratio test page: