[48richard]

Great explanation, 70GMCer, thanks.

I changed out my gears this morning to compensate for larger tires; it took about 2 hours. One thing I found out, though, that the clip holding the drive gear could not be removed with the drive gear in place. There is a tang on the clip that fits in a hole on the output shaft, so the clip cannot slide forward. I held the the two prongs on the end of the clip in with a screwdriver, and then had to tap the gear with a small hammer to slide the gear over the clip.

Anyway, without seeing from this thread how easy this is, I would probably have put it off another year. Now I have a speedo that reads 61 at true 60 from my GPS, with no needle vibration, which I am guessing came from the old gears being worn.