1989 gmc 2500 hd keeps locking up when put in park have to rock the vehicle and it will shift out of park

Page 95 (Section 2-26) refers. It is hidden!

Shift Lock Release This vehicle is equipped with a shift lock release system. If your vehicle has a dead battery and you need to have your vehicle towed, there is a shift lock release lever that will allow you to move the shift lever out of PARK (P). To access the shift lock release lever, do the following:
1. Press on the sides of the boot around the shift lever to release the boot.
2. Lift up the boot on the shift lever and you will see an orange lever.
3. Press the orange lever down and move the shift lever out of PARK (P).
4. Snap the shift lever boot back in place.

https://my.gm.com/content/dam/gmownercenter/gmna/dynamic/manuals/2002/gmc/envoy/2002_gmc_envoy_owners.pdf

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lights stay on for short time after turning off vehicle or when you hit lock or unlock on fob as to auto start either fob battery died --fob malfunction--or you have a check engine code --have vehicle scanned because a pending trouble code may not light up on dash but will disable remote start --if it is a fob problem and you lost programming need to go to a dealer to flash the remote start

are you parked on a hill you may have to rock your car

Sounds like a part called a parking "Pawl" is hanging up. You could try to park the way they show you in driving school, with the rear of the tire against the curb when the car is facing uphill. Theory is that the tire will chock the vehicle against the curb as a bumper stop and prevent rolling backwards. This will minimize pressure on the inside of the transmission parking pawl.

You can go to aboutautomobile.com and search for "Consumer complaints" or Recalls and enter your vehicle info. Then see if others are having problems like yours.

Quite often that will happen when vehicle parked with wheels turned, and/or vehicle on a slope, so try to avoid that in future.If nothing else, when parked on a slope, stop, keep foot on brake pedal, apply parking brake, put transmission in neutral, then take foot off brake pedal and wait for parking brake to stop vehicle rolling, then shift it into park. When leaving, put foot on brake pedal, shift to drive or reverse whatever direction your going, then release parking brake. Sounds like a lot to remember but you won't have to pull hard on shifter as before, and it could save a lot of money on transmission repairs down the road. Always try to park with wheels straight as well.
Now, with that said, if you parked with wheels turned, try hard to turn steering wheel in same direction wheels are turning, just slightly, as you try to turn key. Sometimes a quick yank in that direction will do it. Also make sure shifter is all the way in park before you try it. If your on a slope try rocking vehicle slightly up slope as you push/pull shift lever in to park and try to turn key at same time. If no luck, try pushing brake pedal real hard and try to turn key. Let me know how it goes.

Try rocking the truck while attempting to shift out of park. In the future always set your parking brake before shifting to park and releasing the foot brake. This will keep the weight of the truck from binding the parking lock in the Trans.

On most cars of that year and newer you have to have the engine running and be pressing down on the brake pedal to shift out of park. If that does not work try having some one rock the car forward and back while you try to shift out of park. If the rocking trick works in the future while still in gear and holding the brakes set your parking break then shift to park. This will keep the weight of the car of the parking lock in the transmision and prevent the problem from reoccurring. Good Luck!!

Do not shift into park and move the steering wheel to lock it. It will lock itself if the vehicle is moved or someone tries to steel it. Reason is that the lock pin hsas many holes to drop into and if you lock it when you have turning pressure on in it. You will lock it with pressure on the lock pin.
Second, always set your parking brake before, not after putting it in park. Never put your front tires against a curb and put it in park without letting the vehile roll away from the curb.. An don't hang you car on a slope by putting it in park. Parking brake always befor parking gear and hands off steering wheel when placing in park. Try it, you'll like it.. forcing your shifter to come out of park can cause damage to the shifting componants. Let me know how it works for you. - Ned_

Problem with Diesel Fuel System. Gmc 2002 duramax 2500 HD 4x4 will start 

have you tried bleeding the system with the engine running and turning full lock both ways? also inspect the belt make sure its tight enough
also make sure that you do not have a leak in one of the lines etc.