Have just under 70M mi on LT extended. Leaking fuel when full, found to
be cracked filler 'pipe.' Am original ownder, not aware of any underbody damage - anyone else had this type of prob, know of service bulletin or
'secret' recall, etc ???? Gonna be expensive and frustrating.

yup there is a recall notice for anyone who has the problem, bring your TB to a dealership to have it fixed for free.