oval speedometer

[sidevalve]

I am putting together my first model a and have two speedometers to work with. Both are well used and I am trying to free them up. I have opened them and sprayed WD-40 in all possible places. The one in the best condition spins when I put a square head bit in the cable drive but with still some resistance. My question is, should they spin freely or is there always going to be some resistance.
I dont want to put it in the car and just tear up speedo cables if it's too tight.

 

[30cabriolet]

First things first; get rid of the WD40. Personal opinion, but there are much better lubricants out there.

You should be able to turn the gear with the square hole using just your pinkie finger. If not, the pot metal of the speedo has probably swollen. I have had luck taking a small punch to the inside of the bottom gear that is attached to the vertical shaft. Turn your speedo over and using a hammer and punch give it a slight hit. Do not overhit it as the top wheel has a hair spring that you do not want to damage. This should loosen the bearings on the vertical shaft and allow the speedo to turn easier.

 

[Tom Wesenberg]

Ditto what 30cabriolet just said. In fact someone said that WD-40 is bad with potmetal. WD-40 is not a lubricant and after a few days it will usually be evaporated. I usually use ATF and after tapping the gear (as 30cabriolet mentioned) to loosen the shaft, I then spin it with an electric drill to let the ATF work into the bearings and shafts.

 

[CarlG]

When spinning with an electric drill, spin it in reverse direction to simulate the car going forward.

 

[gunmetal blue]

I have one apart if you want pics e-mail me at terry_rose2002@yahoo.com

 

[Bob Johnson]

Everything you ever wanted to know about speedometer

Check link below for speedometer information. The last selection fixing a frozen speedometer may be useful.

http://www.modelahouse.com/tech/speedometer/index.html


Bob