Keep in mind the mechanism in the speedometer is magnetically driven (while
the odometer is mechanically driven) - look at the round casing in the back
when you have taken it apart. With time, the unit loses it's calibration
(magnetically) and can read close to true, be way off, bounce around, or
just smile back at you. Chevrolet put out a technical manual back then for
recalibration that used a mechanism to "re-magnetize" the unit for a correct
reading. There are still folks out there that have these, and with
reconditioning, should bring the unit back to true (but is big bucks for
some reason). I had to trial test 3 speedo units before I found one that
would read over 55 mph (weak magnet or something) and it's still about 5 mph
off, but close enough for being 50 years old.
Also, if the unit has previously been disassembled and if the casing,
magnet, and spring have been reassembled without the EXACT (correct) number
of turns, then it will improperly read zero (i.e., won't zero out AND will
either read way high or way low). Can speak from experience here.....(but I
got it eventually). This process is how you figure out where to "set" the
needle to zero.
Food for thought. Good luck.
Allen in Seattle
'50 3100
----- Original Message -----
From: "Jim House" <jhouse@ccsolution.com>
To: <oletrucks@autox.team.net>
Sent: Wednesday, November 15, 2000 2:56 PM
Subject: [oletrucks] Speedometer needle
> My original truck (1 year ago) came with a needle that worked for the
first
> 10 miles or so. The odometer has worked without a problem all along. I
> pulled a second needle from the junk yard. Then replaced the needle on my
> speedometer. However it bounced around for a while then broke into two
> pieces. I think I could crazy glue it back together but is this balanced
> and would it affect the correct speed reading? Or should I try a 3ed
needle
> (sounds like Florida) or get the whole thing rebuilt. When I placed the
> needles on before I could not understand where the needle should be
> pointing - there did not seem to be a starting place for the needle on the
> speedometer. There was no D or cutout to push the needle into so it could
> only go on in one way. Any input would be great!
>
> Jim House
> 46 Chevy 3104
> Hollis, NH
>
> I may be back in the posting business again!
>
>
> oletrucks is devoted to Chevy and GM trucks built between 1941 and 1959
>
oletrucks is devoted to Chevy and GM trucks built between 1941 and 1959
|