I am pushing 70 years old, and still are not very smart. I purchased 25' class C motorhome. But it was 3,280 miles from my home. It was in New Hampshire, I live in Idaho. It was the model I wanted, and only made for two years. It had 28,200 +/- miles on it. It ran very well drive at 62 MPH and I got 8.45 MPG for the trip. The entire trip it had a strange noise at times. It did not get better or worse for the entire trip. The noise did not change with RPM nor MPH. It could happen at 20 MPH or 65 MPH. Driving at 65 it would come and go more often. Did not matter if you were going up hill or coasting down hill. But at 62 MPH it did make the noise, but not as often. The sound was like a worn brake pads, but the same sound and pitch at any speed. Pushing on the brake made no difference.

 

A noise like that would make me look at things other than the suspension or engine. Is it possible it's something in the RV?

 

It is in front on the driver side. The external driver side step is loose on the back or rear. I do need to find why it is loose. But I have walk round in the coach, and it is not heard. The passenger side is not as prevalent. Some place on the Ford forum I read that baffles some place under the valve covers had broken loose and made a strange. As usual I did not mark it or save. It was not exactly the same but people do not describe the same way. I wondered it it was or could be the serpentine belt, but it does change with RPM. After 3200 miles one would think something would break or break-in.

 

I had the same issue with my F-450. Turned out to be a bad clutch on my A/C compressor. Even though the A/C worked.

 

That is a VERY good point - it explains it all. NOTE: Even on defroster, the AC will cycle.

 

At least I have a place to start, that does make sense. Do you have a way of testing it. I have always had problem on replacing something, could fail like a bearing or seal. A clutch is not a great deal of money, but replacing the complete compressor is not a great deal more. I will likely have someone do it. At near seventy about all I do any more is change oil, pump gas, and drive. But thank you very much, it was helpful.

 

Funny thing is, the noise may occur when the compressor is NOT engaged if it is indeed just the clutch. The clutch bearing will spin when it's not engaged. If that bearing is shot, it'll make noise.

Easy to to tell, spin the front of the AC compressor clutch by hand even when the belt is on the pulley. Any roughness needs to be dealt with.

 

I have looked at a number of YouTube on replacing the clutch bearing, it does not look like a difficult job. However I have yet to crawl under to see if it can be done without removing the compressor.

 

Depending on how much room you have, you can replace the clutch and bearing without removing the compressor. Clutch is held in by 1 bolt in the center. Bearing by a snap ring. If you have the room, remove the belt from compressor and it can be done in the chassis.

 

I think my noise is coming from someplace other than the AC unit. Was able to remove fiber/plastic cover. The bearing on the AC unit is very smooth. The motorhome only has 30,000 miles. I never have had to replaced AC unit and/or clutch until vehicle has 150,000 to 200,00 miles. It maybe that turning the radio up could solve the noise. If anyone has an other an suggestion would be helpful.