my 2001 f150 Titan 5.4 4x4 Super Crew has a tapping sound coming from the bell housing even in park. The sound varies by engine speed. It comes and goes away some times. I remove inspection plug and noticed nothing unusual....

Prior to the noise (over the last couple weeks) I noticed that once in
a while as the trans shifts it slightly seemed to slip between gears, usually under low torque.

Torque Conveerter problem ????

 

Yes that sounds like the phenolic thrust spacer has died on you. Ford revised that part in 03 on all models so you either need a newer converter or to have one built with bearings instead of that component. I would be concerned that you have overheated that transmission. It sounds like you need a cooler and at the very least a fluid change. If you work the truck hard I suggest just having the transmission freshened up.
Alan

 

dirtydog I have the same issue and I was told it was cam phasers and I should replace motor .

 

Jshultz I'd like to hear more info regarding this issue.. Thanks