Gmc jimmy keeps eating fly wheels and starters. its like motor is locking for a second.

Check and test for a failed bendix gear in starter --flywheel damage or motor seized

Its your starter that is faulty.

you may need to check the fly wheel,,to see if the outer part of it has seperated from the inside..plus check the teeth on the fly wheel...

Hello: You have to remove the transmission to replace the flywheel.

1995-97 4.3L MODELS and 1995-99 2.2L models



Fig. 5: The starter motor on later model 4.3L engines is retained by two long bolts

1. Disconnect the negative battery cable.
2. Raise and support the front of the truck safely using jackstands.
3. If necessary for access, disconnect the front exhaust pipe.
4. If equipped, remove the starter heat shield.
5. On the 2.2L engine, remove the brace rod from the front of the engine and the bell housing.
6. On 2.2L engines, remove the drivers side wheel to access the starter motor wires and the starter motor attaching bracket-to-engine bolt through the opening in the wheel well.
7. Disengage the wires from the starter solenoid.
8. On the 2.2L engine, remove the attaching bracket-to-engine mount bolt.
9. Remove the starter-to-engine block bolts. When removing the last bolt, be sure to support the starter to keep it from falling and possibly injuring you.
10. Carefully lower the starter and shims (if equipped) from the vehicle.
11. If necessary, remove the bracket (2.2L engine) or the shield (4.3L engine) from the starter assembly.
    

To install:

1. If removed, install the bracket or shield to the starter, as applicable. Tighten the bracket nuts to 97 inch lbs. (11 Nm) or the shield nuts to 106 inch lbs. (12 Nm).
2. Carefully raise the starter and shims (if equipped) into position in the vehicle and thread one of the retaining bolts to hold it in position.
3. On the 2.2L engine, loosely install the bracket-to-engine mount bolt.
4. Install the remaining starter mounting bolt, then tighten all mounting fasteners to 32 ft. lbs. (43 Nm).
5. Engage the wiring to the solenoid as noted during removal.
6. On the 2.2L engine, install the brace rod and tighten the retainers.
7. If disconnected for access, install the front exhaust pipe and tighten the fasteners.
8. If equipped, install the starter heat shield.
9. On 2.2L engines, install the drivers side wheel.
10. Remove the jackstands and carefully lower the truck.
11. Connect the negative battery cable.

Hope helps.

Have the battery tested for a dead cell. It may test at 12 volts but that doesn't mean there isn't a dead cell. Also, if the motor has good compression you probably shouldn't be able to turn it over by hand at the fly wheel. Maybe an old school motor with V belt, but not a newer motor with all those accessories attached to the front.

make sure starter drive is engaging. make sure motor is not locked up?

You need to see if the transfer case engagement motor is defective.

You more than likely need a new fly wheel, your fly wheel and starter are probably not making contact

You may need to shim the starter and I would have the starter tested.It is not uncommon to purchase a faulty elecrical part of any type from a part store.