The Stovebolt Site Forums The Shop Area The Electrical Bay Electrolock cable through Firewall grommet 3-'36 All & '37-'46 Trucks

Electrolock cable through firewall grommet 1933-36 All & 1937-46 Trucks

If anyone out there has a 1933-46 Chevy with an electrolock cable passing through a 1 3/8” hole in the firewall at an angle this home made rubber grommet may be of interest. It is made from a 1 3/8” panel plug.

A hole was made at an angle to the firewall to match the angle of the cable.

A fixture was made to hold the rubber plug in slight compression to prevent any tearing of the rubber during making the angle hole that was done with a 3/8” hole saw and a 3/8” end mill, both running at a high speed.

Ray W

That looks like a speedometer cable grommet from a mid 60's GM. I think it was not uncommon then although I cannot remember exactly which application.

Good morning Mac. I've had this '36 Chevy pickup since 1965 and in that time I've found current Ford, Toyota, Porsche, Jeep and non-automotive parts parts that are a direct fit on it. But one thing I have not found, except in antique vehicle vendor catalogs. is this electrolock cable through firewall grommet. The firewall hole is 1 3/8" and the cable is 3/8" and that size grommet with a 1/16" panel groove is something that doesn't seem to exist. When I've called the antique vendors to ask for the actual dimensions of the grommet they offer they don't know, and when pressed they simply guess. That doesn't work for me because I expect parts to fit and I expect vendors to know the details of what they are selling.

Also. the cable passes from the center of the dashboard to the right side of the engine coming through the firewall at an angle. Because the electrolock cable is stiff it deforms grommets with a straight hole to look like the one in the picture. That motivated me to try making a grommet with a correctly angled hole starting with a panel plug with no center hole. Making neat holes in rubber is challenging but even this first attempt turned out OK.

The minimum purchase quantity of the panel plug I started with is 2, so I will probably make another one of these grommets while I have the setup. Maybe some other 1930s or 1940s Chevy or GMC truck owner will want to try it.

Ray W

I found I have one of the original 60's grommets, it has the angled hole and is for a speedometer cable. It fits a 1" hole however, not 1 3/8". I am gonna guess that it came from my 62 Chev pickup, I have seen this size in a lot of GM cars. That doesn't help your 1 3/8" hole but maybe someone else. I would mail this one for a couple dollars to cover the postage, I will never need it (at least until after I send it to someone else!)