Yesterday my tranny did something weird. I reversed out of the driveway and when I shifted down into drive the inducator light went all the way down to "1" then a message displayed on the screen something like "shift indicator malfunction". I shifted back up into park and then counted the gears down into drive and no indicator light showed. I drove on down the road and the truck did not shift into 5th gear. Now this morning everything seems to be OK. What's up?

Bad NSBU. If your truck has under 100K miles you can get your dealership to fix it under the emissons waranty. If not, check out the vendors on this site or a Williams Detroit Diesel Allison distributor and get a new one (the dealership will charge you an outragous amount).

Changing the switch is a DIY project if you're so inclined. Plenty of info here on how to do it.

Thanks, I have less than 60K on the truck!

Whereabouts are you in LBK mjeter?

I'm in southwest Lubbock.