Does the speedometer in your 1993 Ford Ranger with a BW1350 transfer case bounce? Have you replaced the speed sensor gear at the end of the cable? Have you replaced the cable? Have you replaced the speed sensor? Have you tried a different speedometer head? Have you declared that your truck just hates you? Fear not, a solution is at hand.
All the above drove me nuts. For the life of me I could not figure out why the speedometer would bounce – and the cruise control modulate along with it. One day a guy on therangerstation.com threw me a bone and suggested that I replace the speedometer drive gear that was inside the transfer case (BW1350 electronic). Given that I would need to drop the driveline and pull an oil seal, I did not want to simply verify if this was indeed the problem without a new gear in hand. I was able to get the gear from Ford for around $50, plus a new oil seal. As you can see from the photo, the original was completely shot. NOTE: the dirt on the gear because I forgot to take a photo before tossing it in the trash – fished it out to preserve the memory (yes, at some point the mental wound will heal).