Rvac A/c System ???

Does anyone have this type of airconditioning system in their coaches. I've asked Marathon to inspect and service the RVAC system, flush it and lubricate the ducts. The RVAC A/C SYSTEM WITH TWO POSITION "IN-DUCT" DAMPER , the damper needs to be lubricated as it makes a funny noise when it comes on while in the air conditioning mode. each of the 2 RVAC systems are located in 3rd bays, Thermostats for air conditioning and heat are SMX key pad style. these are large units in both sides of the 3rd bays. have any of you had experience with this system?? One uses standard home style air filters one on each side. Is this standard stuff or something special ordered??