Speedometer quit when t-case swapped

[chalet2506]

I swapped Matt's NP203 in for my 203 which had some issues. The new case speedo hookup is on the passenger side, whereas my old one was on the driver side. No big deal, ran the cable over the top of the t-case and hooked her up. Now, the speedometer doesn't work. The cable I had installed when I was still running the old case, and it worked fine then. Its less than 6 mo's old. My only guess is that its binding, but it's not like I've got it pinched around anything.

I've never messed with speedo's, so any help appreciated.

Kurtis

 

[vortec]

my first thought was bind, also. are you sure the new case actually has speedo gears in it? maybe someone pulled them out for some reason.

 

[MattK]

Got your PM, bud. I didn't pull any gears out of the case when I pulled the tcase. I never had new gears thrown in to correct the speedo, but it did work. Is it possible that being on the other side that it also rotates in the opposite direction?

 

[chalet2506]

Let me go put it in reverse and run around the block to see if it'll work that way. There's no telling what the deal is.

I'd think it'd be fairly simple. A gear in the t-case drives the little gear box on the outside, which the cable hooks to and is turned by, which turns the gears in the actual speedo gauge and moves the needle.

Maybe somebody can give me an elementary course in speedo's, and I can figure it out from there.

 

[Blue85]

Being on the other side of the case has no effect and the direction of rotation. The direction and revolutions per mile is standardized so you can even swap speedos between Fords, Dodges, etc.

When I swapped the Dodge fixed yoke onto the back of my Chevy 208 it moved the speedo output to the opposite side and I just rerouted the cable. Works fine.

I would guess that the cable is broken or it is too short so that the square drive section is not egaged at one end. If the problem is binding, where does the slip happen? Wouldn't you strip the plastic gear where it engages the cable? Maybe you can test the cable with a drill to see if the speedo moves.

 

[cowain]

I'm just throwing stones here, but I think there's a possibility that some of the different cases take different sized cables. My speedo doesn't work right now and I've checked it with the drill trick and it works. Everything seems to be right with the t-case so I don't get what the problem is. However, I just bought the truck and it came with another speedo cable loose in the floorboard that is much larger. I'm thinking someone swapped something and didn't match up the new cable sizes. Just guessing though.