Speedometer Problems...Help.... - The 1947 - Present Chevrolet & GMC Truck Message Board Network

rkkeith · 03-30-2003, 12:30 AM

I am having a problem with my speedometer........IT DOESN"T WORK!! I have replaced the cable and when I connect it to the speedometer and turn the cable the needle moves but when I hook it to the transmission (TH350) it doesn't work. I took the gear out and looked at it and it is not worn or looks as if it should work. What else could cause this problem?? I think it would have to be something on the transmission side because the gauge worked before I put in my new engine and transmission. I would appreciate any HELP......Thanks

*Gee_Emm* · 03-30-2003, 11:05 AM

Did you take a look at the gear that drives the gear that you took out?

Reumster · 03-30-2003, 11:10 AM

Mine did that once and the drive gear clip had come off, and the gear on the shaft would just free wheel. I always had most trouble keeping side gears in my tranny. Gear mesh was off. And from burn outs. Speedo gears don't like sudden changes in speed. At least not when your mesh isn't perfect.

Gordo · 03-30-2003, 11:12 AM

Could be the drive gear in trans is not the correct one that matches the driven gear, or vise-versa. It's not hard to gain access to that drive gear. Jack up and support truck from rear (lose no fluid this way), remove driveshaft, remove speedocable and sleeve with driven gear, remove tail shaft housing, depress spring clip holding drive gear onto output shaft and slide gear off. You said you installed a new eng and trans, was the old trans a T350 also? If so, take the drive gear and driven gear from the original trans and install it into the new one.

03-30-2003, 12:30 AM	#1
rkkeith Registered User Join Date: Jan 2003 Posts: 62	Speedometer Problems...Help.... I am having a problem with my speedometer........IT DOESN"T WORK!! I have replaced the cable and when I connect it to the speedometer and turn the cable the needle moves but when I hook it to the transmission (TH350) it doesn't work. I took the gear out and looked at it and it is not worn or looks as if it should work. What else could cause this problem?? I think it would have to be something on the transmission side because the gauge worked before I put in my new engine and transmission. I would appreciate any HELP......Thanks

03-30-2003, 11:10 AM	#3
Reumster L.E.D. Freak Join Date: Jan 2002 Location: Polson MT Posts: 1,358	Mine did that once and the drive gear clip had come off, and the gear on the shaft would just free wheel. I always had most trouble keeping side gears in my tranny. Gear mesh was off. And from burn outs. Speedo gears don't like sudden changes in speed. At least not when your mesh isn't perfect. __________________ Specializing in Custom L.E.D. inserts. http://www.ccled.com/ Contact me @ blazer2wd1972@hotmail.com (406)675-8082 or Joel @ jmcwaters@eps-corp.net 1972 2wd Blazer, 350/700R4/3:73 posi, err & Custom L.E.D. inserts! LOL

03-30-2003, 11:12 AM	#4
Gordo Registered User Join Date: Jan 2001 Location: Killingworth, CT. USA Posts: 3,378	Could be the drive gear in trans is not the correct one that matches the driven gear, or vise-versa. It's not hard to gain access to that drive gear. Jack up and support truck from rear (lose no fluid this way), remove driveshaft, remove speedocable and sleeve with driven gear, remove tail shaft housing, depress spring clip holding drive gear onto output shaft and slide gear off. You said you installed a new eng and trans, was the old trans a T350 also? If so, take the drive gear and driven gear from the original trans and install it into the new one. __________________ 1971 C10 swb stepside 350/700R4/3.73posi (retired as of 4/22/03) 1998 S10 short bed 2002 S10 Blazer 1942 Oldsmobile 1958 Massey Harris Pony 1951 Wife Killingworth, Connecticut May those who love us, love us, any of those who do not love us, may God turn their hearts. And if God is unable to turn their hearts, may he turn their ankles so we may know them by their limping. A man who works with his hands is a laborer; a man who works with his hands and his brain is a craftsman; but a man who works with his hands and his brain and his heart is an artist.

03-30-2003, 11:05 AM	#2
Gee_Emm Account Suspended Join Date: Sep 2000 Posts: 4,002	Did you take a look at the gear that drives the gear that you took out?



Register or Log In To remove these advertisements.

Register or Log In To remove these advertisements.