Glacier, I have been considering that.
To add to the useful info., The large nut takes a 30mm 12point socket and the 4 yoke bolts takes a 12 or 13mm 12 point end wrench. Those 4 bolts were extremely tight!!!! I was afraid that I was going to break the wrench. Use good wrenches when doing this. Also, it is not needed to take the TC rear half apart. Once the yoke is out, remove the large seal and the small shaft seal then put a small screwdrive in the speedo hole to move that piece out. Brooklyn,There was no color variation in the part that I removed and the part that I installed. I don't believe there is a different drive gear available.
When you reinstall everything, make sure the drive gear goes back in as the old one came out. Someone advised me on this but for the life of me, I could not tell a difference. Anyway slide the gear onto the output shaft then put your speedo gear in and tighten it down. You can get to the drive gear to check the mesh/operation then through the output hole. Install the rear seal. Make sure you install it the same way the old one came out. both sides of the seal look nearly the same. Put the yoke in, then install the little rubber seal onto the threaded area. I assume that this little seal is to prevent TC oil leakage around the splines of the output shaft.
Install washer and nut Ford says to run this nut down to 250 ft. lbs.
Install the drive shaft and the for bolts and tighten them down tight!! Check your and enjoy the test drive!!
To sum all this up, What I thought was a bad/bouncy speedo cable turned out to be the drive gear in the TC.
To check your speedo cable, remove the cable assembly from the TC and attach a reversable drill on the end of the speedo gear. Run your drill in reverse. My drive acheived 65 mph. and the speedometer was very steady eliminating all components from there to the cluster.
This is about a 2hr. job if all your tools are readily available first. Some will be able to do it faster some slower. I was not in a big hurry.
Hope this helps!!
Mark