April 1st, 2013

Undercarriage damage to light truck in rocky terrain

Hi everyone,
I'm looking for a quick scene patch detail that involves automotive mechanical details. I have a basic knowledge about car repair, but not enough to be certain on this.

Scene: Somewhere in eastern Utah, hilly country, late at night. 19 yo male decides to sneak home to the family ranch by taking a 'shortcut' he's heard about but never used. The shortcut is a dry, rocky wash that leads to a little used fire/maintenance road which will take him home the back way. He didn't know about it until recently because it's on neighboring land. Halfway up the wash (arroyo? canyon?) he runs over a rock bigger than he thought it was and the truck gets stuck. Something under the truck is damaged, leaking fluid, and the truck is no longer drivable. The truck is a mid to late '90s Ford F150 that has seen better days.

Needed: damage to the underside of the truck that would be identifiable by flashlight to someone who has a knowledge of car repair, just by looking at the rock, the tilt of the truck, and the leaking fluid. The truck wouldn't be drivable even if he could get it off the rock by himself. He can't get under the truck to see the specific damage.

Plot point: the scene purpose is set-up for later pay-off. He has to walk out several miles to get help. Something happens on the way and he disappears. The truck is found later and his relatives realize he didn't just run off on his own - something is seriously wrong.

This question is a little too specific for a general internet search, and I've searched the archives here for ~cars and ~car accidents, but didn't find anything helpful.

I'm thinking cracked transmission?
If it is the tranny, does the fluid stay red after use or does it change color the way oil goes from golden yellow to brown black?
If the truck is stuck on the rock and he doesn't have a winch to pull it off, do I need to increase the tension with the damage or is being stuck enough?
If it's just stuck what kinds of things would Young, Dumb and Stranded try to do to get it unstuck?
(No offense intended, I did lots of Dumb when I was 19. Driving a convertable with the top down in Dec comes to mind.)

Thanks Detailers! Those were just the kind of detals I was looking for. Great answers everyone!