I've been having problems with my speedo for some time now. Kept changing the VSS, because that would fix it temporarily, but I pretty much always new it was the gear reduction box hooked to the transfer case. I was always to cheap to buy a new one (dealer only part, over $100). The gears inside it have gotten worn, and were causing the speedo to jump all over the place. Last night I took the box off, drilled a tiny hole in the plastic cover, and sprayed as much PB Blaster in there as would fit, then I covered the hole with silicone. Went for a test drive, and the speedo now works just as it's supposed to. Don't know how long this will last, but I'll keep you guys up to date, and like I said, it's a cheap fix for a really annoying problem
AJ
AJ