I've read some posts on speedometer and cables, but my question wasn;t in them. So, I have a 71 big block, no A/C. Just how easy is it to replace the speedometer cable? Do you really have to pull the inst panel? Is it easy to disconnect from the trans? And, which cable is it?

Rick

 

Speedo and odo don't move.

 

The speedometer cable connects to the driver's side back part of the transmission, on the extension housing/yolk area. This is true for a TH400, but I don't know about a manual transmission. (You didn't specify in your post which transmission you have)

On the TH400 there should only be a few lines/hoses/cables running off of it so it shouldn't be too hard to narrow it down to the speedo cable. On the passenger side you have two transmission cooler lines, located just behind the bellhousing. Next to that you have the throttle kickdown calbe (also on the passenger side). On the back of the passenger's side of the transmission there is a vacuum modulator where a vacuum line runs from. On the driver's side there is a shift linkage up front and on the back there is the speedo cable.

As far as installing a speedo cable into the dash, I haven't ventured that far in my project yet.

I know I didn't answer you full question, but I hope that at least some of this info helps...

 

It's pretty easy once you've done it before, but it can be a bitch because of where everything is located. (You didn't say what tranny you have.) On manuals, just unscrew the cable housing at the transmission and it's off. I don't know about automatics...

The upper end just snaps on and releases off. You have to press on the spring-type release while pulling the cable sheath away from the back of the speedo and that is the challenge. There isn't much room in there and it's hard to get to because of the steering wheel and seat. Last time I did it, I had to get my head under there, then flip on my back - which really takes it out on your spine. If your seat is out, it really helps. (If you are wondering, it's actually easier to remove the driver's seat than the dash.) I had to use a flashlight too. When you figure out how to compress the spring to release the cable, it practically falls off. From there, it's just a matter of putting a new cable in. It has to go in from the top. It snaps on in a few seconds.

If you have an automatic, I think they are 2 piece units. I haven't dealt with these.

Good luck

 

Its a manual transmission.

Is it a cable within a cable? Do you just pull the interior cable out, or do you replace the whole unit?

Thanks

Rick

 

Well, it's a cable within a sheath - pretty ordinary. Each end of the cable is square so it fits into the end of the gears and speedo. Once you have the top disconnected, you can pull the cable right out. The catch is getting it off. You can actually pull the old one out and replace it with a new cable of the correct length without having to replace the sheath if there's nothing wrong with the sheath.

 

You might have a stripped nylon gear in the tranny.... if it is the same set up as my 74

 

Thanks for the info.