Nissan Repair: 99 ford expedition, shaft bearing, engine bearings

Question
QUESTION: I here what i think is a bearing or out of balance noise coming from the uunderside of the suv while it is in park and running. The drive shaft is not spinning. The noise starts and stops and then eventually goes away. I just repaced the shaft and ujoints and last year repalced the transmission still under warranty. Could it be a out put shaft bearin/ curious   Jon

ANSWER: Jon,

If you get the noise in park, and you are not moving, that would mean it is transmission or engine related.  The output shaft bearing is not spinning when in park, so it could be the torque converter or the front pump making the noise.  Or, the drum inself could be making noise, internal to the transmission.  Other things that can cause this type of noise are the engine bearings is they are worn or a bad balancer.  The best thing to do is get it up on a lift where the noise can be pin pointed.

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QUESTION: are the engine bearings hard to change and or expensive job. The suv has 204800 mile. I am hoping to use it for a coupe of more years.

Answer
Jon,

The engine bearings are not difficult.  But, you do need to jack up the engine to get enough room between the crossmember and engine to get the oil pan out.  Once that is done it is just a matter of removing each main cap, one at a time and replace the bearings with standard replacements.  The rods are the same.  But, at times you will have to rotate the assembly to get to the next rod bearing cap.  Get a torque wrench and a Haynes Manual for instructions.  Be careful and take your time.  It is easy but time consuming and just do one at a time to not mix things up.  Keeps the caps in the same direction as they came off and install the same way and once you are done get a new oil pump while you are in there.  Replace the pan, lower the engine back on the motor mounts and bolt it up, replace the oil and filter and you should be fine.