Case tractor 4wheel drive will not come out - The Times Case Corporation Tractors International Harvestor

Operating - Operator's Manual - John Deere

manuals.deere.com/cceomview/...A9/Output/OMM139226_A95.html
Slow down before you make a sharp turn or operate on a slope. ... Before starting engine to drive tractor, adjust operator seat to desirable position. ..... If lock does notdisengage, depress one turn brake pedal, and then the other. ... The 2-wheel drive (2WD) / 4-wheel drive lever (A) enables the tractor to be operated in two or ...

A Guide To Safe Farm Tractor Operation - National Ag ...

transfer case chain has broken inside case most likely

Look under your truck and see if the shift lever is connected to the transfer case.
Quite often the cotter pin that holds that together comes out, if that's the case just put a new one in and it will engage and stay engaged.

Too much trouble.. look for one that is already factory 4 x 4.

Should have electrical wire going to it.

Disconnect the Manual Lever and turn it by hand, if you can not... then you may have a failure of your Transfer Case.

Try to Manually move the Shifter with your hand on the Transfer Case.. Does this work?

There is a solenoid plunger that is screwed into front axle. Unscrew the plunger turn key on put into 4 wheel dive and verify that plunger is moving. If no movement you have to find out why. If moving, then front axle has a issue. Hope this helps.

you have a bad or faulty sensor that communicates the 4wd position to the dash the sensor is on the top front of the transfer case. Find a large open area and drive in reverse for about 500 feet then put car in drive and pull forward this might enable the sensor to know what position the transfer case is in The transfer case is connected to the transmission and also to the front and rear axles by means of drive shafts. If this doesn't work change you sensor on the top front of your transfer case. hope this helps you please rate me and for further assistance you can always ask me.

I have a 2005 Tahoe that recently had a similar problem. To resolve, I did the following.

1. Change the transfer case fluid (Which you already did)
2. Change Gears to 4L while in neutral, change back to drive, and drive slowly 50 yards or so.
3. Change Gears to 4H while in neutral, change back to drive, and drive slowly 50 yards or so.
4. Change Gears to 2H while in neutral, change back to drive, and drive normally for a couple of miles.

This will cycle the fluid within your transfer case, and hopefully clean out the sensor. I did this, and my Service 4WD light went away after one day of normal driving. Hope this helps. Note: When I went into 4L the first go around, it had a hard time shifting due to non use. I changed between 4H and 4L a few times until it got smoother.