Thor Forums

[chimez78]

I had the same issue as you and believe this is the solution. I too posted this question and a video and received lots of suggestions that did not resolve the problem but after trying to diagnose and solve this over 2 years I believe this is it.
Firstly I have a 2017 Thor Axis 24.1 with the 6.8 V10. We purchased this new in April 2017 with 400mi on the odometer. At approximately 6000mi when driving home from Florida we experienced the same noise as shown by people on the videos in your post. Ours also occurred at 2100rpm was on the driver side and Air conditioning did not seem to affect this at all which confused me because even though it don’t quite sound like it my initial thought was it was the belt.
I figured it was the end of the season and I would take it to be looked at by my local Ford dealer. Let me tell you this whole portion of my story is a nightmare. I wont get into the ugly details but will tell you I took it to the Thor dealership that sold it to me who heard the noise and said it was a Ford issue, which they were right, and had it to 2 Ford dealerships which never properly identified nor remedied the issue and insisted it was a Thor issue after tying up my RV for approximately 2 months and I had Ford Customer Support involved. I must add that I did deal with an individual from Thor in attempting to resolve this, who if I ever meet him in real life I will punch him in the throat, and also dealt with the company that does the frame stretching of our chassis” Moryde” who unfortunately for them ultimately got stuck with Fords bill and it wasn’t even their fault. Moryde by the way was the best company to talk to out of the whole ordeal they were extremely kind and went above and beyond my expectations. It is a very long and complicated story that makes for some good entertainment.
Anyway getting back to the solution. I decided to test my suspicions and change the OEM serpentine belt and voila noise was gone. Unfortunately this was only temporary. The belt I installed was a Dayco from Advance auto parts, although it is listed as the proper belt it was approximately 0.5in longer than the OEM belt which concerned me because I thought to myself that the belt tensioner was already at the further end of its travel which I thought wasn’t a good thing. After driving the RV for about 800mi the noise came back unfortunately this time however it was distinctly a belt chirp and it occurred under the same conditions as the original noise.
So now I decided I am going to buy another new belt and a new tensioner. I did this time I replaced the belt with a Gates Heavy Duty Fleet truck belt and I bought a Dayco tensioner but in doing my research and putting them on I realized there is an open post above the power steering pump. In looking at the belt diagram online it was showing there is supposed to be a idler pully here however there wasn’t. I then consulted the owner manual and saw that the 6.2L engine diagram shows the idler pully is there but the 6.8, which has the same exact belt diagram does not. I thought to myself that given the noise is definitely coming from this side of the engine and discovering that my second belt debris was int this general area I thought it would only make sense to install the idler pully here. So I ordered another idler pully, same as on the passenger side of the engine, 90mmpully dayco part # 89006 and installed it on to the post. Sure enough I took it out and the noise is completely gone.
I believe that if you get a new belt, and install this pully you will find your issue will be resolved as well. This is a relatively new fix for me so I don’t have many miles under it but I am fairly certain this is the solution.