MrBleeble

OK,

I have a 1984 Z28 with a mechanical speedo.

I need to replace my speedo cable/housing as the one that came with the car was in a fairly tacky state. I bought a replacement which stated that it would fit my year/model which is 80 inches long, but the old cable is only 77 inches long. The housing for the old cable is busted so I can't re-use it, but the cable is fine and I happen to have a spare 80 inch housing along with the housing for the 80 inch cable that's going to replace it. I guess I could cut that cable if needs be and re-use the 77 inch cable if the 80 inch turns out to be too long.

However, the main problem I am having is that I removed the old cable/housing but how do I get either end of the new cable through that rubber grommet on the firewall? The hole in the grommet is the same diameter as the cable housing itself, but the cable housing has a metal casing at each end that is much wider. The old cable just pulled through because it was cut/taped at one end, so what do I do? Can I just pull the grommet out, and cut a slit in it with a razor blade so I can put it over the new cable? If I do that, will I have problems pushing it back in?

It seems easier to cut the grommet and push the cable through the firewall from the engine bay to the speedo than to push it through from the interior (mainly because I can't even see the grommet on the interior side of the firewall), so should this work?

Thanks