Speedo noise

N

nathanmac

Member
OK so my noise in the speedo, it sounds dry. Is there a way to lube it in place or is this potentially something that needs removed and dismantled?

What is the main shaft of a speedo lubricated with?

TIA
 
Hi Nathan, Make sure that it is routed with the least possible kinks.
If it is ticking it probably has a broken strand of wire. (need a new inner?) undo the cable at the top and pull it out and check it. lube it with a bit of grease only. If you use oil it can creep up the cable into the speedo and cause problems. When you re install the inner you have to turn it for it to mesh and go into the drive at the bottom. If you need a new inner you can get them made up at an instrument repair place. Good luck!
 
I would use graphite on the cable, not grease. If the noise is in the speedo head itself, you have to remove it. Right near where the cable attaches to the head, there should be a small plug you can remove. It's very small, maybe 3/16 of an inch in diameter. You take it out and there's a pice of felt in there that you'd put a few drops of light oil, like 3-1 oil. Don't flood it, just a few drops. You can work it in by using a broken cable end or a nail filed square and put in a drill. You have to run the drill in reverse only.
 
Barry-ct said:
I would use graphite on the cable, not grease. If the noise is in the speedo head itself, you have to remove it. Right near where the cable attaches to the head, there should be a small plug you can remove. It's very small, maybe 3/16 of an inch in diameter. You take it out and there's a pice of felt in there that you'd put a few drops of light oil, like 3-1 oil. Don't flood it, just a few drops. You can work it in by using a broken cable end or a nail filed square and put in a drill. You have to run the drill in reverse only.
Click to expand...

Thanks, that's the info I need. I re-routed the cable and it seems nice and quiet. I have some graphite but I don't think I need to do anything with the cable. I've never had to lubricate a speedo before so thanks for the advice on what to use.

To go on a bit of a tangent, when I was a kid our Model A speedo used to bounce around a lot and make a real swishing sound. Finally figured out it was the cable that must have been woven the wrong way and would wind up and release as it was spinning. The speedo was never as much fun to try and guess your speed after we replaced it.
 
It wasn't woven the wrong way, it was just made with the drive end at the wrong end.
BTW, I concede that Barry is probably correct regarding the grease verses graphite.
 
The early FoMoCo maintenance manuals only list replacement of speedos, speedo drives, and speedo cables. It wasn't till the 50s that they list a 10,000 mile cable lubrication for the speedometer system. They used the same thing then that we've been using on the helicopters for that last 60 years which is Lubriplate. We clean them & re-lube them every 1200-hours of operation on both the engine tachs and the rotor tachs. The lubriplate will work even if it gets wet.

You can have problems with the drag cup bearings wearing out in the speedo head causing the drag cup to seize to the rotating magnet in there. They will screech like a banshee when that happens. The needle will peg out too.
 
The only one that can be oiled from the outside is the input shaft bushing. There are several threads on the barn about removing the little soft plug and cleaning & servicing the little oiler wick. All other bearing surfaces are internal and require disassembly of the speedo head to gain access. It takes a lot of care to break one open but there are several speedo resto shops around the country that will do it for a fee. Some can make them like new again. Silk screening equipment, bezel rolling tools, and a good calibrator machine are needed for this process. Every fair sized city in America used to have a speedo repair shop but not so much now days with all the throw away mentality that is omnipresent.
 
Rotowrench

I did open mine and removed the brass plug.
Singer sewing machine oil. Reassemble.
So far so good.

Thanks
Bruce

Works good
Lasts long time
 
I had my '33 speedometer reworked by Instrument Exchange Inc. in Houston. This is a shop run by two guys, Joe & Steve who are second generation in this business. They did a good job at a very reasonable price.

Speedo made a lot of noise due to not running since 1971 and had to be disconnected. Their info is below.

larry/Texas

4501 Harrisburg
Houston, TX 77011
instrumentexchange@sbcglobal.net
713.923.6104
713.923.4484 Fax
1-800, 945.GAGE
 
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