VCCA Home Forums TECHNICAL - 1945 AND NEWER 1949-1954 Speedometer question

I thank everyone who participated in this thread. I love my Chevy 4400 and I get a lot of pleasure from putting it back in good shape.

To Andys29 - the local parts store told me that the grommet for the speedometer cable passing through the firewall is not available. But, I ordered it from Jim Carter, so it is available. It's just that the local parts store, which has a fixed set of suppliers, can't get it from their suppliers.

To Junkyard Dog - The guy at Chevs of the 40s told me not to do what you did, specifically, he told me not to just get a needle and push it on. He said I would likely ruin the mechanism inside the speedometer that way. I don't know... this is the first time I have had to mess with a speedometer. I come to Chevy trucks from a long background of tractor mechanicing. None of my Allis-Chalmers tractors have a speedometer. (Top end for a WD45 is about 11 mph.)

Lee Prairie

Don't know why the dude told you that since the reproduction needles are made to be pushed on the needle shaft and the needle that I purchased from the Filling Station pushed on very easily.

In the end, that solution (pushing a needle on the shaft) wouldn't work for me, since after the needle broke, the shaft broke and the 'hub' of the needle fell off with the tip of the shaft still in the hub.

Lee Prairie

Yesterday I spent over an hour trying to get the speedometer cable onto the back of the speedometer. It is almost as though the pitch of the threads on the male part (speedometer) doesn't match the pitch of the threads on the female coupling (cable). It starts and then locks after about 1/4 turn. I drove it about 20 miles and the cable stayed in, but I'm unhappy with this situation. The cable isn't properly attached. :(

Has anyone else had this problem?

I had no problem screwing the cable on and off the old speedometer. I may try a new cable, but the old one should work fine, but it doesn't.

Lee Prairie

I bought a new speedometer cable and it wouldn't go on the speedometer very well either. In the end, the point is to keep the cable on the speedometer so that it operates the speedometer. I could have tried to take the male end off the old speedometer and replace the male end on the new speedometer with it, since both new and old cables fit the old speedometer nicely (but not the new one). But I didn't. Instead, I used pliers to force it on another full turn or so. Something's wrong with the new speedometer coupling.

It works and doesn't come off when you hit a bump. But I hate to have to do it that way.

Lee Prairie

Sounds like the thread pitch is different on the old speedometer vs. the new speedometer. Use a pitch gauge and see if they are different.

Is there something that works well for cleaning the speedometer guts when it is apart? Something like electical spray contact type cleaner for washing out the years of buildup? (obviously keeping harsh chemicals away from plastic parts!)

What is the best lubricant to use inside the speedometer mechanism after a thorough cleaning?

Thanks