I could put it all the way back in 1st then hit each gear until reverse and that's as far as it would go.

 

When I would push the shifter up and towards the dash to get the key out it's staying in reverse.

 

Pull the pan, and have a look at the rooster comb, and associated hardware. See if anything obvious jumps out at you. Also, check for debris in the pan......

 

I'm wondering if someone is in the habit of not using the parking brake, or has shifted into park while the truck was still rolling... and bent the park sprag or park rod. That'd be worth looking into.

 

Well I don't use the parking brake but I park on flat ground 90% of the time. What should I be looking for when I drop the pan?

 

You'd do well to get in the habit of using the parking brake. The park pawl is stout, but it can be bent by the shearing force applied when someone bumps your truck while it's parked, or by being applied while the truck is still moving.

I'm so paranoid that I always set the parking brake before shifting into park.

Chunks of metal, of course. Look at the rooster comb and the parts around it as HeyYou suggested. If nothing obvious jumps out at you, take a good look at the park rod, pawl, and sprag.

Before doing any of that, grab the service manual and read through the applicable sections so you know what you're getting into, how to get into it, and how to get successfully back out of it again.

 

Will I be able to see all of this by simply dropping the pan or will more need to be removed?

 

To get at the park rod, pawl, and sprag the valve body will have to come out. It's not inordinately difficult but you'll want to be paying attention after reading through the manual a couple of times. The rod can foul up by sliding above the pawl and you need to be looking for signs of it as the thing come apart or you might miss it.

That said, given the age of the thing and no indication of mileage, you might be looking at a rebuild. These transmissions generally fall out of service at 130k to 180k miles in normal service, less if neglected or working hard. At the lower end of that range and not working hard they might be salvageable with just governor pressure solenoid and sensor (as well as any neglected band adjustment and fluid/filter change), but they're not likely to go much above the upper end of that range even with those things because bands and clutches have a limited lifespan. Chrysler blew it on these transmissions in this service category, but they've never taken the aftermarket's lead and made these transmissions all they could be. For that matter, Ford never did either -- only GM has the TH400, which is in my totally biased opinion the best juicer ever made.

If your plans for the truck involve only getting a few thousand more miles out of it, then you might want to just fix what's broke if it's cheap enough and let the next owner, AKA "The Sucker", deal with it. If instead you want around 50,000 miles out of it or it's broke beyond simple repair you might be looking at a stock rebuild that'll last until it's The Sucker's turn at it. For anything more than that, a high quality upgrade is probably in order. The good news is that if you want to get another quarter-million miles out of it there are aftermarket vendors who can (probably) get that for you, though of course for a premium price. Among them, PATC gets my money every time though APS is certainly in the running. Dr. Evil, well... I've not owned one but have reason not to.

First things first if you're not looking to spend any more than absolutely necessary is to get the pan and valve body dropped and see if anything jumps out at you. Bent/broken parts and/or chunks of metal will tell the tale straight away. If you see none of that, then pressure testing as outlined in the factory service manual probably will.

 

Well the trans has 196k on it and I've done some heavy towing and it's been on 35's with stock 3.55's for 8 months. I haven't dropped the pan but my trans guy said it sounds like parking rod has broke. I'm going to just pull it out and have it rebuilt. With the miles it has it's had a good run. It's gonna be 1200 with a upgraded converter, bigger bands and better clutches.

 

Thats a damn good deal for a full rebuild with upgrades. Had to pay 2300 for mine (with upgrades and shift kit). Location is everything I guess