Flywheel keeps breaking

What exactly do you mean by "breaking"? Use the comment Button below with more information please.
It takes a hell of a lot to damage the flywheel on the crank shaft end of an engine. Has the flywheel been removed recently? If it hasn't been refitted correctly it can cause big problems. A poorly fitted clutch assembly can also cause issues. A more common reason for damage to a flywheel is a faulty starter motor no releasing properly, chewing off the teeth around the rim of the flywheel.

never knew that a torque bolted to a flywheel, it is always bolted to a flex plate that drives the torque converter and carries the ring gear for the starter
there are washers that fit either of that flex plate or on some engines only on the converter side with the bevelled edge facing away from the plate
the torque converter is bolted to the flex plate by 3 or 4 bolts facing back to the converter from the block end
why are flywheels not used with torque converters
the mass of the flywheel affects the engine acceleration and the torque converter full of oil takes over that job so the engine acceleration would be considerable slower if both were used

Well ill assume your issue is how to keep the engine from turning while your trying to loosen your bolts. If thats it, the proper way is to use an impact wrench. That should brake them loose. Now the shade mechanic would line up the the motor to #1tdc. Now remove the #1 sparkplug. You can thread a bolt with the same size of your plug. Screw it down till it hits the top of the piston. That will keep the motor from turning. I do reccomend getting an impact wrench. Air is the best, but an elec with a high tourqe will also work.

Two major possible causes here:
1. Your starter is not engaging the teeth on the outside of the plate properly, as shown by chewed-up teeth, both on flywheel [actually called a flexplate on automatic], and on starter. Dirt trapped in between the starter and the housing will keep it from mating properly, and cost you big bucks. Shims are available to get the teeth exactly lined up.
2. OR your torque converter is indeed not true to the engine drive-shaft, causing pressure off-center. That would cause the flexplate to break out at the center. If this is how your plates broke, you probably will need a new automatic transmission.
If you also have engine oil back there, the rear bearing of the engine could be shot, indicating bad things. Have a pro check both shafts for sloppy bearings.

The Crankshaft Position Sensor (CKP) is mounted to the transmission bellhousing at the left/rear side of the engine block...






Inatallation: 4.0L Engine
New replacement sensors will be equipped with a paper spacer glued to bottom of sensor. If installing (returning) a used sensor to vehicle, a new paper spacer must be installed to bottom of sensor. This spacer will be ground off the first time engine is started. If spacer is not used, sensor will be broken the first time engine is started.

New Sensors: Be sure paper spacer is installed to bottom of sensor. If not, obtain spacer PN05252229.

Used Sensors: Clean bottom of sensor and install spacer PN05252229.

1. Install sensor into transmission bellhousing hole.
   
2. Position sensor wire shield to sensor.
   
3. Push sensor against flywheel/drive plate. With sensor pushed against flywheel/drive plate, tighten mounting bolt to 7 Nm (60 inch lbs.) torque.
   
4. Route sensor wiring harness into wire shield.
   
5. Connect sensor pigtail harness electrical connector to main wiring harness.

Hope helps (remember to rate and comment this free answer).

Replace the crank sensor.



The Crankshaft Position (CKP) sensor is mounted to the transmission bellhousing at the left/rear side of the engine block. The sensor is adjustable and is attached with one bolt. A wire shield/router is attached to the sensor.

REMOVAL

1. Disconnect sensor pigtail harness (3-way connector) from main engine wiring harness.
2. Remove sensor mounting bolt.
3. Remove wire shield and sensor.

INSTALLATION
New replacement sensors will be equipped with a paper spacer glued to bottom of sensor. If installing (returning) a used sensor to vehicle, a new paper spacer must be installed to bottom of sensor. This spacer will be ground off the first time engine is started. If spacer is not used, sensor will be broken the first time engine is started.

1. New Sensors: Be sure paper spacer is installed to bottom of sensor. If not, obtain spacer PN05252229.
2. Used Sensors: Clean bottom of sensor and install spacer PN05252229.
3. Install sensor into transmission bellhousing hole.
4. Position sensor wire shield to sensor.
5. Push sensor against flywheel/drive plate. With sensor pushed against flywheel/drive plate, tighten mounting bolt to 7 Nm (60 in. lbs.) torque.
6. Route sensor wiring harness into wire shield.
7. Connect sensor pigtail harness electrical connector to main wiring harness.

its in the bell housing on the transmission the flywheel is bolted to the crankshaft and either the tourqe converter or clutch is bolted to that.

itz always gud tagit other opinions before operating-or ull become a parts replacer n daats$$$-i think lookin at the ignition switch may help unless u hav the relay n soleniod thats bad or hooked up rong

Biggest problem on that truck is the crank sensor, it will fail intermittantly and give you the problem you describe. It is located in the bellhousing of the transmission directly behind the cylinder head and below the firewall. I can tell you how to check it, but since you are throwing parts at the problem, put a crank sensor on it. I'm willing to bet that will take care of it. They usually come with a paper spacer on the bottem to keep it from contacting the flywheel, and if it does, just set the spacer on the flywheel and tighten the bolt, if there is no spacer, make sure the sensor isn't touching the flywheel or it will break the sensor as soon as you turn the key. Hope this helps.
Good luck
Roger