We own a '96 Explorer (~ 90,000 miles) with a tow package, although we've done only limited towing with it with a 5x8' utility trailer. No tranny problems. Until recently we lived in Tigard, and on recommendations of friends we've had it serviced 100% at Landmark Ford in Tigard. We've had excellent results for over ten years, although admittedly no major hassles like you describe.
I have no idea what kind of service you're likely to get in Lebanon, but according to my map it would only be about 7 miles further from Newberg to Landmark, all on I-5, so it would take just about the same time.
Landmark is quite large, and I've heard they have the largest parts inventory in the NW. Despite their size, however, we've always enjoyed excellent, personalized service. They have about 6 service managers (Green Team, Red Team, Black Team, etc.), and we always deal with the same mgr. (Red Team). He supervises his own team, so the job does not get lost among a large group of anonymous mechanics. We almost always receive a follow-up call from customer service a few days later -- always a good sign in any business!.
They do charge dealer prices, but we've never felt like they've been trying to encourage any unnecessary work. Their diagnostic skills seem to be excellent. I took it in recently for a squeal coming from the right front, thinking it was brake pads. They diagnosed faulty dust seals on the axles, replaced them, and the problem went away.
YMMV!
iggy
