Is there a universal standard for color vs number of teeth on speedo driven gears ? While I'm replacing my cable (due to speedometer jumping - found the driven end all chewed up), I also pulled the speedo gear to order a larger replacement (speedo reads a little over 90 at 70). Trans is a 700R4 swapped in by the previous owner about 8 years ago, according to him. This is the driven gear that's in it right now:

38 teeth by my count. The drive gear is red, but I'm not up for pulling everything apart to get at it. I just ordered the 40-45 tooth housing and a 45 tooth driven gear; if nothing else, it should get things closer to accurate.

 

700-r4

 

Thanks. I did some more digging, and found the color for a given number of teeth varied among suppliers. So that explains my tooth count not matching a gear I looked up that I figured it should match.

I got a new speedo cable for a 78 automatic w/o cruise from Ecklers, which arrived today. But the stock trans in the 78 must have had the speedometer pickup in a different location. The new cable was about a foot shorter than the one I pulled out of my car. I would have checked before ordering, but the item description didn't give the length... Anyway, since my 45 tooth gear and new housing had already arrived, I pulled the old cable out of the sheath and smoothed it up on the end that was a little messy. I also discovered that the end with the retainer was at the transmission end, rather than the speedometer end like the new one. And it appeared to have been recently lubed. So I slid it back in with the retainer at the speedometer end, fed it back through the firewall, zip tied it in place, swapped out the speedo gear and housing on the tranny, and hooked it back up. Now my speedometer reads within 3 or 4 mph at 30, and within about 2mph at 40. I have yet to hit the freeway and see where it is at 70mph. It's handy to have my trusty Passport IX on the dash to provide a GPS speed to compare to; and if I have the speedometer reading pretty close, the trip odometer ought to be more useful

Wow ! Three weeks ago, very little on this car worked right except the engine, trans, and suspension. At this point about the only things not working are the dome & courtesy lights, the entire heater system, and the factory alarm and a/c (both of which have been removed altogether).