my 78s odometer/ speedometer failed mid drive
Thread Starter
4th Gear
Joined: Aug 2008
Posts: 4
Likes: 0
my 78s odometer/ speedometer failed mid drive
help.. could use some wise insight. i was told that the cable came disconnected.. and that the transmission may need to be dropped to reconnect, with a pricey estimate... i need it fixed immediatly, is it that big of a job.. or was he taking advantage??? should i take it elsewhere?? (auto tran) thanks everyone... cheryl. 
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
help.. could use some wise insight. i was told that the cable came disconnected.. and that the transmission may need to be dropped to reconnect, with a pricey estimate... i need it fixed immediatly, is it that big of a job.. or was he taking advantage??? should i take it elsewhere?? (auto tran) thanks everyone... cheryl.
I'm pretty sure you can reach the transmission end of the cable from the ground under the car. The speedo cable is replaceable in the car.
Jack the front of the car up, slide under it, and inspect the cable. It may still be attached, and all you need is a new component.
Do you have cruise control? Might be the transducer.
Race Director
Joined: Oct 2000
Posts: 12,681
Likes: 3,134
From: Shamong, NJ
78 automatics use a 2 piece cable. Without cruise the cables have a male and female fitting and connect together. With cruise both cables have female fittings on both ends. The lower cable runs from the trans to the cruise transducer, the upper runs from the transducer, through the firewall, into the speedo. With or without cruise, the cable attaches to the left (driver) side of trans. You should be able to reach it from underneath with the car on a lift, or jack stands.
Most likely it is one of the cables, with the lower probably being the easiest to replace. It could also be the plastic drive gear in the trans, which can be looked at by pulling the fitting out of the trans that the cable attaches to. Occasionally, the gear in the speedometer head goes bad, which requires rebuilding or replacing the speedo. Or, as Durango boy stated, it could be the transducer. Good luck.
Most likely it is one of the cables, with the lower probably being the easiest to replace. It could also be the plastic drive gear in the trans, which can be looked at by pulling the fitting out of the trans that the cable attaches to. Occasionally, the gear in the speedometer head goes bad, which requires rebuilding or replacing the speedo. Or, as Durango boy stated, it could be the transducer. Good luck.
Thread Starter
4th Gear
Joined: Aug 2008
Posts: 4
Likes: 0
I'm pretty sure you can reach the transmission end of the cable from the ground under the car. The speedo cable is replaceable in the car.
Jack the front of the car up, slide under it, and inspect the cable. It may still be attached, and all you need is a new component.
Do you have cruise control? Might be the transducer.
Jack the front of the car up, slide under it, and inspect the cable. It may still be attached, and all you need is a new component.
Do you have cruise control? Might be the transducer.
Thread Starter
4th Gear
Joined: Aug 2008
Posts: 4
Likes: 0
78 automatics use a 2 piece cable. Without cruise the cables have a male and female fitting and connect together. With cruise both cables have female fittings on both ends. The lower cable runs from the trans to the cruise transducer, the upper runs from the transducer, through the firewall, into the speedo. With or without cruise, the cable attaches to the left (driver) side of trans. You should be able to reach it from underneath with the car on a lift, or jack stands.
Most likely it is one of the cables, with the lower probably being the easiest to replace. It could also be the plastic drive gear in the trans, which can be looked at by pulling the fitting out of the trans that the cable attaches to. Occasionally, the gear in the speedometer head goes bad, which requires rebuilding or replacing the speedo. Or, as Durango boy stated, it could be the transducer. Good luck.
Most likely it is one of the cables, with the lower probably being the easiest to replace. It could also be the plastic drive gear in the trans, which can be looked at by pulling the fitting out of the trans that the cable attaches to. Occasionally, the gear in the speedometer head goes bad, which requires rebuilding or replacing the speedo. Or, as Durango boy stated, it could be the transducer. Good luck.
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