Speedometer
Thread Starter
Cruising
Joined: Nov 2009
Posts: 12
Likes: 0
From: Destin Florida
Speedometer
My speedometer went Tango Uniform a while back. After replacing the left rear wheel assy I'm getting ready to tackle the speedometer. I took out the cable a while back and it was not broke or twisted and the ends looked ok. The mph needle was pretty erratic before it quit. Anyone know if the guts are the most likely culprit or the gear at the trans (4 speed)? I imagine it's a little easier to start at the trans.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
Erratic speedometer readings [in a 1973 car] are due to: a cable binding inside its sheath (due to wear); speedo drive gear square-drive socket being worn out (so the cable skips); and/or the speedometer head going bad (least likely of the three causes). Remove the drive gear from the tranny to see if the cable drive socket is worn (rounded out) or split. If it is not damaged, Replace the cable. You can try lubricating the cable, but the thing is 40 years old...let it "rest in peace".
Thread Starter
Cruising
Joined: Nov 2009
Posts: 12
Likes: 0
From: Destin Florida
Thanks 7T1Vette. I'm heading to the tranny first. I already pulled and replaced the cable with a new one (after some lithium grease). The cable I pulled was not damaged at all that I could detect. It was not lubed very well but had not kinks or binding. I felt the cable housing going into the tranny last night without the car being up on stands and it felt kinda wobbly/loose although it was tight. I plan on jacking it up later as I'm doing breaks on my other car this morning and oil change in the OL car.
Burning Brakes
Joined: Jan 2006
Posts: 1,152
Likes: 23
From: Kawartha Lakes and PEC, Ontario
Same thing happened on my 72 a while back. Needle jumped around alot then stopped. I also suspected and replaced the cable but it ended up being the plastic driven gear in the trans that had failed.
Burning Brakes
Joined: Jan 2006
Posts: 1,152
Likes: 23
From: Kawartha Lakes and PEC, Ontario
Sounds like a problem with the guage. There's only 1 cable that feeds the speedo. The cable and the driven gear in the transmission must be doing their jobs or neither would work.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
Your odometer has a reset cable on it with a **** at the bottom of the driver's dash. They get sticky after many years of low use. It could be that the reset cable is just disengaged. Work with it a bit to see if it starts working again...before you go digging into 'stuff'.
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