GM speedometer cable

[Xander Wildeisen]

Does anyone know if there is a difference in the size of the inner cable/wire, on GM speedometer cables? Were some years different? Not the length, or the outer jacket. Just the size of the squared ends that go into the speedometer and into the speedometer drive assembly in the transmission?

[deaddds]

I think it depends on the years. I’ve got several nos units that are complete in terms of sheathing and sometimes specific ends. Then others that are just the cable, usually square ends and I suppose you snip the length to fit. Not sure what to do with no sheath.

[cheezestaak2000]

as i recall, replacement cables are cut to fit, then heat the cut end so you can melt  it into the plastic end piece that comes with it. check first to make sure both ends match up with trans output point and back of speedometer. but i think it's a one size fits all kind of deal

[Xander Wildeisen]

Thank you for the answers. I installed the cable and it is working. Drive assembly on transmission looks to have a tapered opening. So it looks like a larger drive cable is needed. Cable is a new 72 inch cable for 1982ish GM cars. This is installed on a 700R4 transmission, going to a stock 1949 Hudson speedometer. Everything is working, speedometer is not reading correct because of colored drive gears, gear ratio and tire diameter. Have done this before on other Hudson's, just need a external ratio adapter. To get the speedometer to read correctly. At about 35 miles per hour, I am reading 28-30. Just need some pacing with another car to get exact readings for different speeds.

[TTR]

Not sure about GM cables per se, but with some makes car vs. truck cables are different thicknesses. 

Also, some tachometer drive cables are often thicker than speedometer cables.

[joe_padavano]

The crimp-on square drive ends are all the same for GM transmissions from at least the early 1960s on up. It's 0.104" square. The flex cable is 0.130". The female part that the square drive goes into is typically the shaft of the plastic speedo driven gear. If it's tapered, that because it's worn.

 

 

 

There are also presses for squaring the end of the flex cable without the crimped-on fitting. Note that the dies do come in different sizes, but the GM standard is 0.104".

 

[Xander Wildeisen]

There is no question that can not be answered on here.

[rocketraider]

I want to know where Joe P found that wonderful toy!😎

[joe_padavano]

8 hours ago, rocketraider said:

I want to know where Joe P found that wonderful toy!😎

 

Unfortunately, Glenn, that's not mine, but now I have to locate one for myself. 😁

[padgett]

"colored drive gears" the adapter gear that meshed with one on the transmission was plastic (one is shown) and coloured according to the number of teeth.

[JACK M]

Been thru this recently.

The gear on the tail shaft needs to fall into the range of the gear that is under the cable. (one size fits some)

In my case I had to take the tail housing off as it was set up for electronic speedo.

So had to change the whole set up.

It wasn't difficult to get the math or the kit with some searching.