Any known issues with 4.0 4x4 Automatic's??

I just bought a 93 Cherokee 4.0 4x4 with an automatic for $825.
I am rebuilding the motor since the existing one has a rod knock w/136K miles (It appears that the previous owner was hard on this vehicle).
Are there any things which typically fail on the 4.0 automatics which I should replace while I have it apart??
For instance, I have been told to change the rear main (these fail on the 4.0's apparently). Also I was advised to change the motor mounts and the crankshaft position sensor.

Thanks much

PS - The trannie & drive train appear to be ok....I plan on changing all the fluids.

tranny mount.
Check the ehaust manifold for cracks.
Might want to pull the t-case halves apart and check the chain for slack.

Are you sure its a rod knock? Could be piston slap, also a cracked or loose flexplate has been know to mimic a rod rap.
Thw AW4 tranny is pretty much bullet proof, one of the strongest auto. tranny's ever built.
Have you checked under the carpet for moisture and rot, these are notorious for it.

Yes, I checked the flex plates out.
Also, it could be piston slip but it's really really bad and never actually goes away. Piston slap should stop when the motor warms up.
And I did pull the carpets and I have some dampness under there.....I know that the weld seal above the right liftgate in the back needs sealer...This is where I think the H20 is coming from

Thanks much for your help

The fenders also tend to be bad, most here trim them out. Also the stock springs, those get swapped out a lot too...or added to. And the stock sized tires, theres reasons you don't see many on here with those. Then if you do swap out the bad tires there are known issues with the stock gearing.

Sorry its been a long day at work sarcasm was needed.

The only other thing to watch out for while doing the engine work is watch out for all your vacuum lines, most running problems people ask about are vacuum related. And keep in mind, anything you replace try to upgrade if you can, no sense in replacing something with a stock part if theres a chance you will want to upgrade in the future.