OK, this problem is making me /forums/images/graemlins/angryfire.gif I went and bought a speedometer cable from the local parts house for my 79 K20, installed it and drove around the parking lot, getting my truck up to 5mph, it worked just fine but the next day when I drove it down the road and got past 10mph the speedometer stopped reading speed. So I got to looking at it and the end of the cable that goes into transfer case housing twisted off, I replaced it again and it did the same thing Any one have any thoughts on why this is happening? Could it be the gear in the transfer case is bad? I hope this is an easy fix, I do not want to have to pull the transfer case just to fix it. If it is the gear in the transfer case, does any one sell the speedometer gears to compensate for larger tires?