MaxPwr

The B13 SR20DE has four motor mounts: right side, left side, front, and rear. This how-to will explain how to replace the rear motor mount. Apologies for not including pictures.

Removing the Rear Motor Mount
1. Begin by jacking up the front of the car. Use jack stands to support the car while you work. NEVER WORK UNDER THE CAR WHEN IT IS SUPPORTED BY ONLY A JACK. Chock the rear wheels.
2. Detach the left side splash shield under the engine from the crossmember. The crossmember is the large piece of black metal that runs from the front of the engine to the rear of the engine. You will need to remove the single 12mm bolt that attaches the splash shield to the crossmember.
3. Remove the 14mm bolt that attaches the crossmember to the front motor mount. The bolt will be located roughly above the bolt that you removed in step 2.
4. Put a piece of wood on top of a floor jack and place the jack under the oil pan. Raise the jack until it lifts the engine slightly by applying pressure to the oil pan. This will relieve the force on the rear motor mount. Leave the jack in place until you are done replacing the motor mount.
5. Locate the rear motor mount. It is sitting on top of the crossmember at the rear of the engine. On the right side of the motor mount is the head of the bolt that goes through the motor mount and secures the motor mount to the block. Using a 14 mm socket, extension, and ratchet, remove the bolt. You will need an extension to get enough clearance to move the ratchet.
6. Remove the two 14 mm bolts that attach the crossmember to the frame at the rear of the engine. Be careful to support the crossmember until you remove the bolts, or the crossmember can fall on you.
7. Now remove the two 14 mm bolts that attach the crossmember to the frame at the front of the engine. Be careful to support the crossmember until the two bolts are removed or the crossmember WILL fall on you. Remove the crossmember from under the car.
8. The rear motor mount is attached to the top of the crossmember by two 14 mm bolts. Remove the two bolts and take out the motor mount.

Installing the Rear Motor Mount
9. Install the new motor mount to the crossmember and tighten the bolts (not sure about torque specs).
10. While supporting the crossmember, install the two bolts that attach the rear of the crossmember to the frame of the car. Torque to 33-40 ft.-lbs. If necessary, lift the engine a little more using the jack.
11. Install the bolt that goes through the motor mount. Torque to 33-40 ft.-lbs. If necessary, lift the engine a little more using the jack.
12. Install the two bolts that attach the front of the crossmember to the frame of the car. Torque to 33-40 ft.-lbs. If necessary, lift the engine a little more using the jack.
13. Attach the bolt that connects the crossmember to the front motor mount.
14. Reattach the bolt connecting the left splash shield to the crossmember.
15. Make sure all bolts are torqued to spec.
16. Gently lower the jack supporting the engine.

All done!