Labor Day Putting down your wrenches or time for
MORE wrenching? 
Plenty of places to share. | | Click on image for the lowdown. 
====
| | | Forums66 Topics128,005 Posts1,055,266 Members48,418 | | Most Online14,466
Apr 26th, 2026 | | AD Chevy Trucks  Over 6,000 pictures Brad Allen has an awesome collection of Chevrolet factory pictures that he has set up from film strips. Check them out!
Lots of work on Brad's part ... pure enjoyment (and references) for you!
| | THANKS!
For helping keep this great
old truck web site
on the Internet for over 30 years! and not clogged down
with Ads!  Again, thanks!
| | | | Joined: Jan 2005 Posts: 310 Shop Shark | | Shop Shark Joined: Jan 2005 Posts: 310 | The odometer in the 51 quit working. The plastic worm gear has broken. Does anyone know if the odometer from a 90 mph speedo will work in the older 80 mph speedometer? Thanks for the help!
-Tim
'51 Chevy 3104 w/'56 235, 848 Head, HEI Dizzy, Corvette Cam, Split Manifold and Dual Carter YF's
| | | | | Joined: Dec 2001 Posts: 14,522 Moderator: Welcome Centre, Southern Bolters, Legion Hall | | Moderator: Welcome Centre, Southern Bolters, Legion Hall Joined: Dec 2001 Posts: 14,522 | My vote is that they will but wait for someone who knows for sure.
......I also found out, and have seen them, that some years ago the speedo's in some LaFrance fire trucks are the same as the AD gauges just in case you know were some old fire engines are sitting.....and they will have less wear on them. | | | | | Joined: Jan 2005 Posts: 310 Shop Shark | | Shop Shark Joined: Jan 2005 Posts: 310 | I figure they will, too. But, I don't want to assume.
Thanks for the tip on the LaFrance fire trucks. I don't have access to one right now, but you never know what might pop up.
-Tim
'51 Chevy 3104 w/'56 235, 848 Head, HEI Dizzy, Corvette Cam, Split Manifold and Dual Carter YF's
| | | | | Joined: Jun 2004 Posts: 8,597 Riding in the Passing Lane | | Riding in the Passing Lane Joined: Jun 2004 Posts: 8,597 | All the old cable driven odometers are figured 1,000 revs per mile.
They say money can't buy happiness. It can buy old Chevy trucks though. Same thing. 1972 Chevy c10 Cheyenne SuperIn the Gallery Forum | | | | | Joined: Feb 2000 Posts: 5,190 'Bolter | | 'Bolter Joined: Feb 2000 Posts: 5,190 | You could probably swap out the little gears and keep the original parts that show. Like George said above, they all are built for the same revolution count. | | | | | Joined: Aug 2018 Posts: 1,004 'Bolter | | 'Bolter Joined: Aug 2018 Posts: 1,004 | okay i'm curious
which gear is "plastic worm gear"?
i've only taken apart about 4 speedometers to date ranging from 1950-53 years, both 0-80 and 0-90 type and that recent special 0-140 KPH metric speedo.
All the gears and worms are metal up to the first odometer counter.
Input shaft worm (steel) -> first gear to worm shaft (steel) -> second gear to worm shaft (steel) -> idler gear (metal, maybe brass) -> 1/10 ths wheel on odometer (odo is plastic).
maybe a photo would help
thanks
| | | | | Joined: Jan 2005 Posts: 310 Shop Shark | | Shop Shark Joined: Jan 2005 Posts: 310 | That was my mistake. I haven't looked at the setup for a while, and I remembered it wrong. It is the plastic gear on the tenths wheel of the odometer that is pretty well stripped. I'm sorry for the confusion.
-Tim
'51 Chevy 3104 w/'56 235, 848 Head, HEI Dizzy, Corvette Cam, Split Manifold and Dual Carter YF's
| | | | | Joined: Aug 2018 Posts: 1,004 'Bolter | | 'Bolter Joined: Aug 2018 Posts: 1,004 | No problem we all forget things yeah
I’m pretty sure some places sell the whole odometer
So that sounds like what you need
Maybe it was chevs of the 40s that had it at one time
Else there should be many in the wrecking yards but you will need to put new number stickers on most.
I counted 14 teeth on the one I have on hand
Don’t know if that’s universal
-s
Last edited by 2ManyTrucks; 01/30/2020 12:42 AM.
| | | | | Joined: Jan 2005 Posts: 310 Shop Shark | | Shop Shark Joined: Jan 2005 Posts: 310 | If anyone else is interested, Jim Carter offers the odometer by itself. They make no distinction between 80 and 90 mph speedos.
-Tim
'51 Chevy 3104 w/'56 235, 848 Head, HEI Dizzy, Corvette Cam, Split Manifold and Dual Carter YF's
| | |
|
|
