Speedo Gear Question - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Synestran · 02-01-2016, 12:00 AM

Hey guys,

Searched around on this forum for a little while and couldn't really find an answer to my problem.

When I bought my truck (1969 C10 292 3OTT), the speedometer wasn't working. Replaced both the speedocable as well as the white driven gear and still it is still not working. Some times if I take the driven gear out and put it back in, the speedometer will bounce but not be close to the actual speed and barely go passed 15 mph. Would this been that the drive gear is worn out or something else? I've taken the cable off the back of the speedometer and noticed that it does not spin unless the bottom portion is connected to a drill so I'm guessing it isn't connecting with the drive gear in the transmission.

The drive gear inside the transmission is blue in color and I'm not sure what gears I have in the rear.

Any help would be appreciated.

midniteblues · 02-01-2016, 09:28 AM

sounds like the drive gear could have stripped teeth. or the bullet gear is stripped where the cable goes into it(square hole).

i'm pretty sure the driven gear in the trans will always be the same in a sag 3 spd., its the bullet gear you change for speedo calibrations.

i would look both parts over very carefully you should be able to see inside the trans to the drive gear. spin the driveshaft in neutral to see the whole gear.

geezer#99 · 02-01-2016, 09:37 AM

Drive gear never gets stripped!!
The retaining clip does break and the drive gear just spins on the shaft.
There's a pic of the clip right at the top of the page in this link.
http://www.transmissioncenter.net/sp...n_______va.htm

Tailshaft has to come off to fix it.

Synestran · 02-01-2016, 01:07 PM

I was able to turn the drive shaft by hand and look at the gear turning and didn't notice anything that looked like a retainer clip on in. Does that retainer prevent the drive gear from moving around? The times I checked it, it was always in the same spot and didn't seem loose when I put my finger in there to feel it.

geezer#99 · 02-01-2016, 01:18 PM

That clip holds the gear locked in place. If you didn't see any clip it might be broke off.
Try reaching in and spinning it. Or jam it in place with a dowel (pencil) and spin the driveshaft. If part of it is still under the gear it might not slide back and forth but will spin.

02-01-2016, 12:00 AM	#1
Synestran Registered User Join Date: Nov 2015 Location: Oregon Posts: 88	Speedo Gear Question Hey guys, Searched around on this forum for a little while and couldn't really find an answer to my problem. When I bought my truck (1969 C10 292 3OTT), the speedometer wasn't working. Replaced both the speedocable as well as the white driven gear and still it is still not working. Some times if I take the driven gear out and put it back in, the speedometer will bounce but not be close to the actual speed and barely go passed 15 mph. Would this been that the drive gear is worn out or something else? I've taken the cable off the back of the speedometer and noticed that it does not spin unless the bottom portion is connected to a drill so I'm guessing it isn't connecting with the drive gear in the transmission. The drive gear inside the transmission is blue in color and I'm not sure what gears I have in the rear. Any help would be appreciated.

02-01-2016, 09:28 AM	#2
midniteblues Registered User Join Date: Jul 2011 Location: strausstown pa Posts: 3,394	Re: Speedo Gear Question sounds like the drive gear could have stripped teeth. or the bullet gear is stripped where the cable goes into it(square hole). i'm pretty sure the driven gear in the trans will always be the same in a sag 3 spd., its the bullet gear you change for speedo calibrations. i would look both parts over very carefully you should be able to see inside the trans to the drive gear. spin the driveshaft in neutral to see the whole gear. __________________ 81 camaro 355 4/spd 342 posi my first love. 67 swb step 454/4spd ott 373 posi 4/7 drop. 2000 s10 zr2 little blue truck that never gets stuck. '74 heald super bronc vt8. tecumseh powered moon rover.

02-01-2016, 09:37 AM	#3
geezer#99 Registered User Join Date: Aug 2009 Location: Bowser Posts: 13,542	Re: Speedo Gear Question Drive gear never gets stripped!! The retaining clip does break and the drive gear just spins on the shaft. There's a pic of the clip right at the top of the page in this link. http://www.transmissioncenter.net/sp...n_______va.htm Tailshaft has to come off to fix it.

02-01-2016, 01:07 PM	#4
Synestran Registered User Join Date: Nov 2015 Location: Oregon Posts: 88	Re: Speedo Gear Question I was able to turn the drive shaft by hand and look at the gear turning and didn't notice anything that looked like a retainer clip on in. Does that retainer prevent the drive gear from moving around? The times I checked it, it was always in the same spot and didn't seem loose when I put my finger in there to feel it.

02-01-2016, 01:18 PM	#5
geezer#99 Registered User Join Date: Aug 2009 Location: Bowser Posts: 13,542	Re: Speedo Gear Question That clip holds the gear locked in place. If you didn't see any clip it might be broke off. Try reaching in and spinning it. Or jam it in place with a dowel (pencil) and spin the driveshaft. If part of it is still under the gear it might not slide back and forth but will spin.



Register or Log In To remove these advertisements.

Register or Log In To remove these advertisements.