I was up in the mountains this weekend and it rained the whole time. The truck had no problems while driving around in the rain. The driveway to the cabin had a slight grade to it and I parked facing downhill that night. It took me five times to finally get the truck going, had to rev the engine to go into reverse or drive, and had to come off the mountain in 1st at 2000 rpm to keep from killing the engine. I had to drive thirty minutes before it started acting normal. Is moisture getting somewhere it should not and/or is there a trick I can do to "waterproof" an important component causing the problem?

------------------

 

Oh yeah. It's a 99 150, 5.4, auto, 4x4, SCab.