A New Banging Sound After Year #6 - In The B+ Cap Area

We just completed our four week August trip with our 2007 2350.  It now has over 23,000 miles.  During the trip, the rig has developed a new distinct and abrupt banging noise when driven.  I have narrowed it down to the area above the windshield.  It is quite a bang from vibration of which I am able to quiet completely when opening the cabinet above me the driver, grab the cabinet, and hang on it while driving.

Once home, I removed everything from the motor home that is not nailed down, drove the motor home to work, and the noise continued in the same manner.  I ruled out the TV because the sound is not coming from that area at all.  I'll be dropping the head liner because the distinct sound seems to be right in the area of the interior cab spot lights.  I have also noted that there are wires laying on the headliner slapping it on road bumps, but they are nothing compared to the distinct and irritating banging.

One more thing.  As part of my investigation while driving down the highway, I rolled down the driver window, my wife doing the same on the passenger side.  We stuck out our hands and placed a finger between the aero-cap gasket and the Ford chassis roof.  In the rounded corner (very easy to reach), there is a whole lot of movement between the aero-cap and roof, while being driven.  A bumpy road amplifies the condition, but not dramatically.  I really don't know what to make of that.  It might be normal or it might be excessive.

Has anyone experienced such banging and found the cause?

I also kindly ask you feel between the gasket and Ford roof (while driving) and report back as to your experience with that.

Ron,

We are two weeks into our five week trip around the southwest, we are in Santa Fe for a few more days but I will check the movement between the cap and roof when we hit the road.  Our 2551 has 24,000 miles on it and I have not heard the noise you describe.  Could something have come loose behind the TV and is bouncing around?

Bob

I'd bet a little money a few of the sheet metal screws that bind the cap to the cab have stripped or broken. If so, recommend replacing the screws with stainless machine screws and Nylock nuts.

Bob/Ron
   Ron I had posted earlier about a small leak on our unit while driving at the cap area, , you have probably diagnose my problem it leaks when raining and were driving.. I caulked once,,, leak is now smaller
 
 Also is the noise all the time or only when you hit a rough patch, since you described a banging I'm assuming when you hit some rough patch on the road??  Something loose,,,, did you check those two outlet boxes, we have two, pass side cabinet, IF the back of them came loose, hitting that cap would be noisy,,, we also have those courtesy lights about the mirror, same thing,,. only thing I can think of,,,, keep us posted which I know you will

Bob   the screws you are talking about are they visible?   I replace nearly every screw on the outside of my unit with stainless when I first got it back in Jan. Lots of rust and corrosion on the one I replaced.
sparky

Ron, on my 2010 2350, the cap started making a rattling noise.  By the time I got from AZ to the factory, it had become a VERY loud noise.  They took out the cabinets and put in additional screws in the cap/cab.  It took them about 4 hours and many more screws/test drives before the rattle stopped.  Hope that's not your problem, because it was quite a job getting it fixed. 

First of all, thanks for all the replies.

What I refer to as "Banging" could actually be a very loud single "Creak".  It does not have to be a very rough road to make the noise, though some amount of rough ride is required to create the noise.

I had it in the back of my mind that I might have to remove the front cabinets to get to the mounting screws that hold the B+ cap to the roof.  If I go there, as suggested I would replace all screws with stainless bolts with nylon locking nuts and stainless fendor washers, and add more of them spaced 2 or 3 inches apart to resemble rivots on a school bus.  If I can do so without being evasive, I would even add a thin rubber gasket to close any gaps and reduce noise.  Something like a continuous strip of bicycle tire inner tube material.

One more thing I observed which could be influential.  My head liner goes 8 to 10" rearward to the decorative padding under the TV.  That headliner and padding all moves together in unison, up and down, under rough road conditions.  There is a significant amount of vertical flexing going on there.  I don't know if this has always been so, or something that has developed over time.

I fear in the end, I will be disassembling more than I care to.  If I do, I will over-kill any reinforcement so I never think about this one again.

Yuck,,, do not like the sound of a creak,, rather would like to hear a banging sound,,, Lmichael advised he had to go get his cap reset,, was it brand new???    Ron you have been on the forum a lot longer than me,,,, I think I just about read every post ,, do not remember seeing this problem before,,,,, I have fingers crossed that you find something else. Know you will keep us posted  good luck
sparky

Yes, my 2350 was only a few months old when the noise started.  The noise was actually a creaking noise--the rubbing of the cap against the metal cab.  THe repair job lasted the next 2 years I had the PC, so they did a good job fixing it.

lmichael
    tks for letting us know,,, goes back to Brand New unit and getting the bugs out,,, someone had a bad day or ?? when they attached your cap on the 2350  ,,,, I'm just hoping that Ron's problem is not the same,,, hopefully will hear from some othet owners if they had this problem.   He does such a good job, I know he will get it figured out and let us know
sparky

I'll do what is needed to get our rig right.  I am known to be quite handy so I am comfortable digging into my bang or creak or whatever it is.  I've learned over the years that anything that will require my time to this capacity, some amount of over-kill in the repair process is most often the better choice.

We got back from our 4 week trip last Monday on Labor Day.  The following day I started 12 hour work days, 6 days a week again.  Our PC is outside getting cleaned by God and his creation.  Live bugs are eating the collection of smashed ones.  I do hope to clean the rig today and maybe have some time to dig into the banging/creaking.  Who knows, I might get lucky and identify the culprit right away when pulling down the headliner.  I'll keep you updated with pictures where applicable.

I really hope to hear from you all in regards to the movement while driving, felt between the B+ cap gasket and Ford roof.  It would help to know up front if I have a normal or abnormal situation there.  The movement we have is felt both on the driver and passenger side so if we have a condition, it is uniform in that way.

We just returned from a trip to Wisconsin and noticed that starting in the morning we had a "creaking" noise above the driver that sounded like it was in the front compartment next to the TV. After several miles it would quit. This went on for the whole return trip. We removed the books we store in the compartment, but it had no effect. At first I thought it was the satellite antenna that was moving until it locked itself, but it could have been expansion/contraction of the roof cap on the chassis. Since returning home it seems to have quit, but I'll keep checking to see if it returns especially in cooler weather.

Way back i posted in regards to my ex-2551 having a very large rattle right over the drivers seat and when I took the headliner down I found a 2 inch wide strip about 18" long  of roof cut away steel that was attached on one end that was dangling enough that over a rough bump it would hit hard on what was left of the cut away roof below.  It was metal on metal and made a racket.  Perhaps over time you have something similar and and it is just now starting to hit what is below?   I am sure you have all seen these questionares as to what you would want in the perfect RV....there is no question in my mind that I would want a coach that does not have rattles and squeaks!  Right now on my 2012 I am hearing huge squeaks coming from the drivers side rear spring pack.  I have sprayed them with everyhitng and i can not stop the squek that is very loud in the coach.  Just like a front end alighnment issues  I am now getting the run around from all my local Ford dealers that they can not look at the issue becasue their lifts are not large enough to get the rig up in the air.  I now have toicall Ford and see if they will OK and will pay for taking the rig to a spring shop.....what a pain, Ford sells these chassis and can not service them, atleast not here in NH!

Way back i posted in regards to my ex-2551 having a very large rattle right over the drivers seat and when I took the headliner down I found a 2 inch wide strip about 18" long  of roof cut away steel that was attached on one end that was dangling enough that over a rough bump it would hit hard on what was left of the cut away roof below.  It was metal on metal and made a racket.  Perhaps over time you have something similar and and it is just now starting to hit what is below?

Thanks for sharing that.  I'll be on the look-out.

Nearly every B+/C motor home manufacture cuts the roof of the chassis, either for easier access in a C or opening up the interior in a B+.  I always considered that risky but it is so commonly practiced.

For reference, here is a picture taken in the PC factory.  I pulled it from the 2007 slideshow presentation on PC assembly.  I don't see how metal-to-metal could be banging unless the factory added some metal.


Yesterday was my first chance in doing something after our trip, so I washed the exterior and cleaned out my waste plumbing.  It took all day.  I just couldn't work inside until the 20,000 bugs and crud was gone.  If I get into that B+ gasket, I want it to be clean.

Anyone yet perform that test in driving their rig and feel for gasket-to-roof movement?

Yes, Ron. I've done it many times. Ours makes no noise and has very little movement between the cap & steel roof joint.

The " long sliver" of left over cut roof metal was actually hitting the front cross member that your photo shows so very well.  It was like a little diving board!  Best of luck getting yours torn apart and you wil have to tear apart for my bet is the front cap has broken loose from being afixed to the cutaway and is really hitting hard on bumps.