John:
I had an M3 service done at the Freightliner Oasis Service Center in Tolleson, AZ in February of 2007. Tolleson is in the West Valley just off I-10 and the 101 freeways join up. Kirk Ault is the service manager. I know you would really like him--he is the best and the techs are most knowledgeable.
Look up some service reviews for this shop at the RV Service Review web site--http://rvservicereviews.com.
Their shop rate is $110. and the M3 service on my 2004 Journey took 6 1/2 hrs. + parts. They serviced my quiet diesel genset as well.
Their address is 9600 W Roosevelt St.
Tolleson, AZ 85353
Phone: (623) 907-9900
Email:
kault@fazltd.com
Good luck!