Puzzled... Why won't my truck go?

[Melbatoast]

I have an '86 Chevy K30/CUCV with the standard 6.2L diesel, TH400, NP208, D60/14bolt setup with a camper in the bed. Here's a little background before I get into the problem. Two weeks ago during elk season I parked it with one of the front tires on a rock. While packing our elk out of the woods i left the ignition switch on to charge some handheld radios... it killed the batteries. Anyway we decided to just camp there for the night and hope someone drove by in the morning for a jumpstart. To get the camper more level I put the truck in neutral to roll the front tire off the rock, no problem. Then in the morning after getting a jump I put it in reverse and nothing. Tried shifting into all the different tranny/transfercase combos and it still wouldn't budge. Both tranny and t-case linkages are good so it is something internal. I disconnected the drive shafts and spun them around by hand thinking maybe it would line something up in the t-case... nothing. Also there were no clinking or abnormal noises of broken metal in either the tranny or t-case. Basically park works but every other gear acts like neutral.
When I parked it it was working great. So a real nice guy towed me down the mountain to a mechanic shop (btw people in Kremmling, CO might be the friendliest people on earth.) The mechanic took a look at it and all he could figure is that for some reason fluid is not flowing in the tranny. He said he thought some component in the tranny is failing, and recommended a rebuilt tranny. Which would be easy if I had $800 bucks lying around .
So any ideas? I towed it home and am looking for a starting point.

 

[yellowK20]

Front pump in the trans MAYBE.

sounds kinda fishy most likely a linkage issue

 

[mtnman]

I agree it's the pump. My k5 did a similar thing last year, (although I was driving at the time) it lost all function in any gear except park. It's odd that it happened on yours after driving to where you stopped....

 

[fouronereason]

I know this prob wont help, but I had a 04 Dodge truck (POS) that if I parked it on an incline or decline it would lose all gears until the fluid was level in the pan, 1 of the reasons I traded it, but since you rolled it off the rock then started it, doesnt make sense. I know this is a stupid question, but did you check fluid level and condition?

 

[Jessie James]

Yeah, have you checked the fluid level? Maybe it was low and needs to be topped up. I know my old Blazer was empty and I thought it was a bad tranny when it just needed some juice!

 

[bigred81]

Drop the pan to see if there is any metal or clutch material in the bottom of the pan and if not the problem may be the front pump or the torque convertor may have shelled out.

 

[K85 Octane]

sweet, I'm first to say Welcome!!!!
First post and already a member. Or is there some background I'm missing lol

Well, first things first. We have a working Park gear ahahahahahaha
sorry
this sucks, I hope your hunting day was better
I can only agree with what's already been said. Check level, drop pan, check fluid. Maybe before you drop the pan, start the engine and listen underneath the truck. Might be faint, but something could have let loose I guess inside the TC. Dunno

 

[79rustyk10]

If its not a severe lack of fluid, Id have to say its kaput. I would think it to be pretty rare to just lose all function at once, but weirder things have happened. Can you rev it up and move it at all that way?

 

[y5mgisi]

low fluid level

 

[andyblack]

I'm going with low fluid level. My truck with the TH700R4 is the first vehicle I've ever owned with an automatic, and it took me about three years to finally learn how to check the fluid level properly. One time the truck would go into any gear at all, so I put too much fluid in it by mistake. That made it blow the seal. Later on, the truck would barely move in reverse. On hills it wouldn't move at all. I thought it was toast, but after someone schooled me about where the fluid level should be when the trans is cold vs. warmed up fully and how to put the trans in each gear and wait five seconds then check the level, etc., I finally got it right. Automatics are wierd.