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Discussion Starter · #1 ·
I can't get the speedometer to work. The guage will register speed when turned from behind by hand. I bought a new speedometer cable (the old one was burnt on the headers). Installed it into the back of the guage (tightened down well) routed underneath attached the toothed insert with retainer clip and put into the transmission. The end is flush at the insertion point and the retainer is tightened down. Still no readings - what am I missing.

Thanks
 

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Chuck the end of the speedo gear (at the tranny end of the cable) up in a hand drill and watch the speedo while you are spinning it. Try both ways in case you are running it backwards.

If the speedo needle moves then the drive gear in the tranny is stripped and needs to be replaced.
 

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Mine was doing the same. The gear was all chewed up.
 

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Speedo cable turns counter clockwise. If it works from the driven gear end the trouble is in the trans drive gear.
 

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Discussion Starter · #6 ·
The speedometer is working with the drill attached. There is some minor damage to the gear (at the end of the cable) - I am ordering a replacement. If it is transmission drive gear, how do you fix it?

Many thanks!
 

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After unscrewing the speedo cable from the gear housing, remove the small bolt(s) holding the retaining plate in position. The housing containing the gear has an O-rin to prevent transmission fluid from leaking out. It might take a little jiggling to pull the housing free, as the seal is tight. Be prepared for a little trans fluid to leak out when the plate is removed. Having a rag or drain pan under the tail housing will prevent a mess.
The original gear is removed after the housing is taken off. It simply is pulled out and the new gear inserted. Trans fluid lubricates the gear, so no additional lubrication is required. Observe the way the original gear is fitted into the trans housing. It meshes with another gear in trans housing, which spins it and the speedo cable, registering your speed at the dash. Pretty simple in a high-tech world. The procedure is the same for either manual or automatic transmissions that have an external speedometer cable. Someday these gears will no longer be available, so if you're planning on keeping your car for a long time, get an extra gear just to be safe.
 
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