my speedo dosen't work?
Senior User
Joined: Nov 2002
Posts: 315
Likes: 0
From: Clayton CA
my speedo dosen't work?
There's a three step process to find your problem.
1. First, check to make sure that the speedometer cable is attached properly to the speedometer. This is the hardest part because it's a pain to get your hand under the dash, through all the cable harness, to the back of the speedometer. However, this is the most likely place for a problem to develop so you need to check it first. The speedometer cable attaches with a nut. If it seems like the nut is more or less tight then it probably is okay. If it is loose, tighten or reattach.
2. Crawl under the truck and detach the speedometer cable from the transmission; it's held in place with a small bolt. On the end of the speedometer cable should be a small plastic gear. Inspect the gear. If it looks like the teeth are mashed, or there is a worn spot, or any other kind of damage, this is your problem. If it looks okay, try to look into the hole in the transmission where the gear was inserted; there is another, larger, plastic gear in there. Try to see if this gear is okay; a small flashlight might help or you can use your finger to feel around. If the gear inside the tranny is damaged (or missing!) this really sucks because you have to disassemble the tranny to change it.
3. If everything so far has checked out have a friend watch your speedometer needle while you spin the gear on the end of the speedometer cable with your fingers. If the needle doesn't move try spinning the gear in the other direction. You're not looking for a lot of movement on the speedometer needle, just a bump. If the needle doesn't move then your cable is broken or stripped and needs to be changed.
The checkout process might sound time consuming but it probably took longer to read this post then to do the actual work.
1. First, check to make sure that the speedometer cable is attached properly to the speedometer. This is the hardest part because it's a pain to get your hand under the dash, through all the cable harness, to the back of the speedometer. However, this is the most likely place for a problem to develop so you need to check it first. The speedometer cable attaches with a nut. If it seems like the nut is more or less tight then it probably is okay. If it is loose, tighten or reattach.
2. Crawl under the truck and detach the speedometer cable from the transmission; it's held in place with a small bolt. On the end of the speedometer cable should be a small plastic gear. Inspect the gear. If it looks like the teeth are mashed, or there is a worn spot, or any other kind of damage, this is your problem. If it looks okay, try to look into the hole in the transmission where the gear was inserted; there is another, larger, plastic gear in there. Try to see if this gear is okay; a small flashlight might help or you can use your finger to feel around. If the gear inside the tranny is damaged (or missing!) this really sucks because you have to disassemble the tranny to change it.
3. If everything so far has checked out have a friend watch your speedometer needle while you spin the gear on the end of the speedometer cable with your fingers. If the needle doesn't move try spinning the gear in the other direction. You're not looking for a lot of movement on the speedometer needle, just a bump. If the needle doesn't move then your cable is broken or stripped and needs to be changed.
The checkout process might sound time consuming but it probably took longer to read this post then to do the actual work.
Senior User
Joined: Jan 2003
Posts: 451
Likes: 0
From: Balfour
my speedo dosen't work?
Take the dash out and check the hole the cable goes into, it can get rounded off causing jumps or no needle action. If the cable isn't busted or kinked out of use it would probaly have something to do with the drive gear in the tranny. The gear is cheap but its inside the transmission...
