Speedometer

Peter J

Peter J

Well-known member
Got bored and thought I'd check out my speedomoter (no cable) just to see if it was clean. The input shaft is pretty stiff and everything looked dry of any lube. No rust but the shaft at the cable input is really stiff. Should it be that hard to turn? Do I need to take it apart?
Thanks for any input guys,
Pete
 
Les Andrews has instructions & illustrations in his book. He also recommends that if you've never done it before to let a speedometer rebuilder do it for you.
 
the answer your question is no ,neither the cable or speedo cable should be stiff or hard to turn, if either is the sppedo needle will bounce, or the cable itself will twist into, and as was mentioned have the speedo serviced by a company that does that, the cable and housing both need to be cleaned, the cable is easy, remove it from the housing and soak in minerial spirts (paint thinner) wipe clean and dry , lube before reinstalling, flush out the housing with the thinner
 
If you don't want take it apart, a couple of drops of a penetrating lube like PB Blaster might loosen the shaft a bit.

I recently refurbished a Waltham round speedometer with a stiff input shaft, and it was caused by dried-out grease in the main shaft and the odometer gears.
 
When I got my Coupe running the speedy was very noisy and jumping all over the place. I cleaned and greased the cable but that didn't help. Everyone said to buy a different one or get it rebuilt so I figured I didn't have much to lose if I took it apart and screwed it up. I followed someone's advice on FB and copied these instructions;

If it is a Stewart-Warner you will see a oblong metal plate on the bottom of the speedometer just in front of the fitting for attaching the drive cable and housing.

Carefully remove that small plate and you will have access to the bevel drive gears which were originally greased.

Remove all of the old grease.

I then, with the unit upside down, fill the cavity with my favorite penetrating lubricant and turn the speedometer in the normal direction until the bearings loosen up.

Once free, drain and flush the cavity and grease.

The oval plate can be reinstalled with super glue.

I also recommend removing the unit from its case and cleaning and lubricating the bronze bushings.


This worked like a charm for me, smooth, steady speedo and I did it myself for hardly any $$ :)
 
Thanks Greg. I have the bottom access plate and see the goo around the gear. I've penetrating oil on it and turn it now and then. Everything else looks clean. Looks like the bevel gear and shaft were exposed crud at one time cause the metal cover was hand made. I'll keep at it.
Thanks,
Pete
 
Update: I took it apart. Removed all the indicators and now I'm down to the shaft and bevel gears at the input shaft. I've spun it with a drill, soaked the shaft in penetrating oil and it's still relatively stiff. It moves free but I can't get it to loosen up any more. I'm also not in the mood to spend $200 for a referb. unit. Problem is that I don't have one to compare it to.
Pete
 
I suggest that you place the carrier upside down so that the oil will work its way down the vertilcal bearing (I clamp the carrier in a vise). Then fill the cavity with your favorite penetrating lubricant. Let it sit at least overnight. If you then turn the speedometer in the normal direction, the bearings will eventually loosen up. Gar Williams
 
I've done what Gar suggest several times. If after that it still is too stiff, then I use a large punch with a flat end that just fits down inside the pocket at the top of the shaft. I give it a downward tap with a small ballpeen hammer. Be careful doing this because the threaded end of the main shaft is very thin and easily broken. A couple light taps has really made the shaft turn much easier for me.
 
Thanks Tom. I've been soaking every orface with little success. I'll give a whack. I assume that breaks up some of the hardened goop on the main shaft.

Pete
 
Peter J said:
Thanks Tom. I've been soaking every orface with little success. I'll give a whack. I assume that breaks up some of the hardened goop on the main shaft.

Pete
Click to expand...
I think the potmetal housing expands a bit with age, and tapping the shaft helps to loosen it a little.
 
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