Speedo

Dbbc

Dbbc

Senior Member
Aloha,
My speedo is not working anymore, the other day I took a drive and looking down at my speedometer it was going wild, from 0 to 45 (while I was driving at a steady pace, probably around 35mph) and then suddenly stop working.
I checked the speedometer with a drill...seemed to be working, check the cable...seemed to be fine, check the speedo gear...seemed to be fine while it looked fairly used. Any ideas what the issues might be, also If I want to get another speedo gear, how many teeth??? I have a 29coupe. I think the transmission is stock.
Appreciate the help... as always.
 
My last encounter with a speedo going bonkers, the cable got all twisted up and finally gave up due to crud buildup in the cable housing, and this can wipe out the drive gear off the ******. I would suggest removing the drive gear, clean and lube with new gasket and check the cable with the drill while hooked to the speedo and see if it doesn't do it again.

Also, while you have the drive gear out, check for busted teeth.
 
DA. I think you mean the driven gear??

With the cable removed check to see if the driven gear moves when put in gear and the rear up on stands
 
Oh, both, hook the drill up to the cable and make sure it runs the speedo constant, AND check the drive gear with a wheels up.
 
Spin the driven gear in the aluminum housing while you slowly lift it into place to check exactly how much mesh the teeth have. You might be driving the cable with just the tips of the teeth due to a wrong housing for the driven gear.

Also be sure the cable is clean and lubed and has no sharp bend of kinks.
 
Pull the inner cable out and check it for damage, especially at each end where it fits in the driving gear and the speedo.
 
You have to check to see if the cable is all the way in the speedometer. If it can move down it will stop working the speedometer.
 
Papanick will "cringe":eek:, but Vermins' main shaft in the speedo was SEIZED in its' pot metal bore. I understand that's common thing, with pot metal.
Without completely disassembling it, I drilled a series of 1/16" holes along its' length & drilled slightly into the shaft, to form "oil pockets":eek:. Filled the holes with 2 Cycle Oil, several times & laid it in the SUN, to soak in.
I FINALLY got it to turn a little, then SLOWLY began to turn it CCW, with the drill & it freed up:D (YAY!) I also removed the plug, over the BEVEL gears, cleaned out the OLD HARD grease & re-packed it with Vaseline.
Would I do it AGAIN? I don't rightly know??? I surely WOULDN'T take the WHOLE thing apart, to replace the number tape!!! The OLD numbers just gives it a little "PATINA":rolleyes:
I had lost contact with my Friend @ Johnnies' Speedo, here in town.
If anyone is in doubt, better send it to Papanick:D The Man's just trying to make a LIVING:D
I have a "weakness" of wanting to "FIX" everything, once got my arm STUCK in the pipes, under the sink, Pat brought me a PILLOW! GOD, I sure miss her!
Bill Fixit
 
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When the speedo went wild, it can only be due to high friction in the speedo head. It causes the cable to wind up and let go before it breaks, or something that drives the cable breaks. It is usually the cable.
What usually Happens, is the main shaft binds up. Big job getting it out to fix it, but that drilling holes in it sounds great. Can't wait to try it.
 
Hay I have rebuild a lot of them that has had the holes drilled into them. It works but it puts a lot of oil inside the case. It just coats all the inside parts. Hay but before you do that check the cable good and see if it can move down in the casing.
 
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