One of the common repairs that needs to be made on an older Jeep Cherokee is replacing broken motor mounts. While the look difficult to access, changing motor mounts is actually a fairly simple process.
Begin by acquiring a new set of motor mounts. Many vendors offer stock replacement mounts style with a lifetime warranty. I use these on my street Jeeps. There are also some heavy duty aftermarket mounts available with either polyurethane or rubber bushing that is fully enclosed in a metal sleeve. I use these on my Rally Racing Jeep.
Begin by placing a jack under the oil pan to raise the engine. Use a block of wood to distribute the load so as not to damage the pan. Lift only high enough to remove the load from the broken mount. You will see it separate slightly when the load is released.
Access to the left side mount can be facilitated by removing the air box. Use two 18 MM wrenches to remove the main bolt. Then remove the two bolts that hold the motor mount to the frame. One of the bolts may be more easily accessed from below the Jeep.
If you have run the Jeep for a while with a broken motor mount, inspect the exhaust manifold for cracks while you are in there. Once the motor mounts separates, the exhaust keeps the engine torque form rotating the engine leading to cracks in the manifold.
To install the new mount, set it in place over the mounting bolts and start them in just a turn or two. Now install the main bolt through the mount and tighten it down. The main bolt can be very difficult to line up if the mount is bolted in place first. Now tighten the frame mounting bolts.
To change the right side mount, you will have to remove the oil filter adapter from the engine block. It is a good idea to replace the o rings when reinstalling the adapter. These O rings are available as a kit from the Jeep dealer and many online sources.
As on the left side, remove the main bolt. The bolt will hit the oil filter adapter before it clears the motor mount so that is why the oil filter adapter has to be removed from the block. Next remove the bolts that hold the mount to the frame.
Place the new mount in position and loosely fit the frame mounting bolts. Install the mina bolt and tighten. Now tighten the frame mounting bolts.
Reinstall the oil filter adapter using new o rings as appropriate.
Lower the engine and enjoy your new motor mounts. If you have installed aftermarket style mounts, you will likely notice slightly more engine vibration. The extra vibration is most noticeable when the starter motor is engaged. Once the engine is running, there is very little extra vibration transferred to the body of the Jeep.