Toyota corolla. replaced battery.starter. positive and negative terminals and wires. starter spins but does not engage flywheel. slight grinding noise from starter when i turn the key off.. help

Wrong size starter.
Incorrect tooth count on drive gear.
Solenoid not working ptoperly.

Can't be much, it's only a motor with a slide solenoid.

does it spin real fast without clanging and grinding against the flywheel? if so then its probably the solenoid bad. do you have to hit the starter with a hammer then it works? it is probably bad brushes or a worn motor. eather way i think you can only get a new starter and solenoid together not sold seperate. check for bad battery cables (loose).

The grinding noise is the starter hitting the fly wheel. This means that the starter is spinning but may not be engaging all the way. Your Flywheel is probably missing a few teeth now. I recommend replacing starter and flywheel. If you're on a tight budget then you could just replace the starter but it will cost you more in the long run.

Locate the battery. (right side front engine bay) look down and to the left. see that little cylinder with the fat wire going to it? that's the starter. Its in between the transmission front side, and the radiator. You should be able to see the long bolts going into it from the back side of the starter. First remove your battery and set it aside then open the plastic access cap to get to the terminal. Remove the wiring. once wires are free of starter, remove the long bolts. slide starter towards the right of the engine bay. It should be free now and in your hand, ready to be tested or replaced. To test it, get a second person to help. get a set of jumper cables. connect the negative side of the battery to the metal casing of the starter and connect the positive side of the jumper cable to the places where you removed the wires. Hook up the negative battery lead of the jumper to the negative battery terminal. Touch the positve lead to the positve terminal. Warn your buddy before doing this because the starter will try to twist as it spins up. If the starter spins, and you see the gear (throwout) push forward towards the tip, then starter is okay. Do this test, let me know what happens, and I can tell you what to check next.

REMOVAL & INSTALLATION 4A-F, 4A-FE and 7A-FE Engines

1. Disconnect the negative battery cable.
2. Remove the air cleaner assembly (with hose).
3. Disconnect all the wiring from the starter terminals.
4. Remove the starter mounting bolts. Remove the starter. To install:
   
5. Attach the connector to the terminal on the solenoid switch. Connect the cable from the battery to the starter and secure with the nut.
6. Place the starter in the flywheel bellhousing, tighten the mounting bolts to 29 ft. lbs. (39 Nm).
7. Install the air cleaner assembly.
8. Connect the negative battery cable.
9. Check the starter for proper operation.

4A-GE Engine

1. Disconnect the negative battery cable. Remove the both engine under covers.
2. Remove the front exhaust pipe.
3. Remove the electric cooling fan.
4. Disconnect all the wiring from the starter terminals.
5. Remove the starter mounting bolts. Remove the starter. To install:
   
6. Attach the connector to the terminal on the starter solenoid. Connect the cable from the battery to the terminal on the switch and secure with the nut to 29 ft. lbs. (39 Nm)..
7. Install the electric cooling fan.
8. Install the front exhaust pipe.
9. Install the left and right engine under covers.
10. Connec the negative battery cable.
11. Check that the starter works properly.

From what you describe I would suspect that the starter is not fully engaging. I'm assuming that the grinding noise you hear when you try to engage the starter is INSTEAD of the engine cranking. If I assumed wrong, ignore the following:
Pull the starter, check the flywheel for excessively worn areas. Most of the time the flywheel is ok, it's just the starter. Any time you disassemble a starter you should replace the bushings and brushes. Never remove the starter with the battery still connected. Remove the negative terminal from the battery before you attempt to remove the starter.

if all connections at starter and battery are good and battery is fully charged then you may have a bad starter.( new does not mean good) hope this helps good luck.

most likely have a wire pinched , or crossed . i bet the first

I believe you have a gear reduction starter,it sounds like the starter drive is not engaging the flywheel.You probably need to replace your starter.

Can't tell you without looking at the battery, it may be in backwards...This is what you need to tell the difference between positive and negative:
The positive terminal usually has a plastic red cap over the wire. The positive wire is usually red.
The positive wire leads to the fusebox, and the starter.
The Negative wire connects to the fender. Is is usually closer to the fender. Let me know if this helps, a FixYa rating would be greatly appreciated.