Dodge Repair: Thank you + New Question, rubber grommet, dodge durango

Question
I was able to eliminate the air pocket in my cooling system for my dodge durango with 180K.  Everything checks out great.  Another question:  No problems with my Tranny other than a leak.  It can leak excessively while parked or not at all.  Thoughts? Maybe a new seal? Big trouble? or a Pain in the Neck?
Thanks,
Greg

P.S. Also The gas guage doesn't work accurately.  I'll have to drop the tank and replace the sending unit right?  Again I ask BIG JOB, Pain in the neck, or walk in the park.

Thanks again
GG

Answer
first the gas gauge.. yes its a drop of the tank and its a royal pain.. just have an extra person and a few hours..
as for the transleak.. I recommend changing the rubber grommet where the dipstick meets the trans seems like after 40000 miles they start to cut themselfs causing leaks