I have a 96 explorer with 191471 miles, just the other day it started to buck, and the spedometor droped, I brought it to a service shop they told me that the Vechical speed sensor and the ABS sensors were bad and replaced them, and that the gear was chewed up and replaced
Do these sensors really go bad, and would that cause my truck to run rough, How long should these sensors last with regualar oil changes and new plugs can I get another 100000 miles out of the truck?

I haven't had the problem with the explorer yet, but I did have the same problem with the speed sensor on my 93 lumina , but it didn't include the abs sensors, fords may be different.

It's the speed control doohickey. I recently received a recall notice for mine. This is fairly common; I had the same problem with cruise control parts on a '96 minivan crapping out.

The symptoms, as you describe them, do sound like an issue with the speed sensor. For your Explorer, the vehicle speed as used by the speedometer and cruise control is derived via the ABS control module from the rear axle speed sensor. The front sensors wouldn't have an effect on your cruise or speedometer, but the rear certainly could have.

Does your Explorer have the V6 or the V8? If the V8, you might be able to get another 100k out of it. If the V6, you might get another 100k with good maintenance, but I'm not sure I'd be relying on it to haul my family around in the dead of winter.

-Rod