1974 speedometer trouble shooting
Drifting
Joined: Oct 2005
Posts: 1,615
Likes: 150
From: Forth Worth TX
I would check the connection at the transmission and see if it is connected properly. If not, connect it.
If it is connected properly, I would disconnect it, put a drill motor on the drive cable and see if the speedometer moves. If the speedometer moves, the drive gear in the transmission needs attention.
If the speedometer doesn't move, I would disconnect the cable at the back of the speedometer, run the drill motor(still connected at the transmission end) and see if the drive cable moves. If the drive cable moves, the speedo needs attention. If the drive cable doesn't move, it needs replaced.
In addition, the plastic end of the drive cable (on the tach side) should be square, if it's rounded off the drive cable will need replaced. e.g. The speedo locks up, the drive cable is still turning and the plastic square tip gets rounded off. Just fixing the speedo won't fix the problem.
If it is connected properly, I would disconnect it, put a drill motor on the drive cable and see if the speedometer moves. If the speedometer moves, the drive gear in the transmission needs attention.
If the speedometer doesn't move, I would disconnect the cable at the back of the speedometer, run the drill motor(still connected at the transmission end) and see if the drive cable moves. If the drive cable moves, the speedo needs attention. If the drive cable doesn't move, it needs replaced.
In addition, the plastic end of the drive cable (on the tach side) should be square, if it's rounded off the drive cable will need replaced. e.g. The speedo locks up, the drive cable is still turning and the plastic square tip gets rounded off. Just fixing the speedo won't fix the problem.
Last edited by Revi; May 29, 2014 at 08:20 AM.
Le Mans Master
Joined: Oct 2006
Posts: 6,842
Likes: 285
From: Palmdale CA
I would check the connection at the transmission and see if it is connected properly. If not, connect it.
If it is connected properly, I would disconnect it, put a drill motor on the drive cable and see if the speedometer moves. If the speedometer moves, the drive gear in the transmission needs attention.
If the speedometer doesn't move, I would disconnect the cable at the back of the speedometer, run the drill motor(still connected at the transmission end) and see if the drive cable moves. If the drive cable moves, the speedo needs attention. If the drive cable doesn't move, it needs replaced.
In addition, the plastic end of the drive cable (on the tach side) should be square, if it's rounded off the drive cable will need replaced. e.g. The speedo locks up, the drive cable is still turning and the plastic square tip gets rounded off. Just fixing the sppedo won't fix the problem.
If it is connected properly, I would disconnect it, put a drill motor on the drive cable and see if the speedometer moves. If the speedometer moves, the drive gear in the transmission needs attention.
If the speedometer doesn't move, I would disconnect the cable at the back of the speedometer, run the drill motor(still connected at the transmission end) and see if the drive cable moves. If the drive cable moves, the speedo needs attention. If the drive cable doesn't move, it needs replaced.
In addition, the plastic end of the drive cable (on the tach side) should be square, if it's rounded off the drive cable will need replaced. e.g. The speedo locks up, the drive cable is still turning and the plastic square tip gets rounded off. Just fixing the sppedo won't fix the problem.
Thread Starter
Navigator
Joined: Jun 2011
Posts: 9
Likes: 0
From: Cheshire Massachusetts
As soon as I disconnected at transmission I found the issue. The inner core (cable) was frozen and in turn got all chewed up. New cable coming in today for install tonight. Onward and upward.
