Belt Line Repair

[Chargerman]

Almost all of the failed screws on my coach or on the front 10-15 feet. I’m guessing part of the cause of the failure is due to chassis twist over the years. Did you see similar failures Chris?

[throgmartin]

When going over uneven surfaces such as driveways, etc. the twist of the house frame is transferred and exaggerated towards the front and rear corners. This is why there are so many popped belt lines on the corners. You will get them elsewhere but those are mainly caused by leaks into the beltline which causes the screws to rust. 

So you are right, the twist of the house frame can pop beltlines loose if they are not riveted.

[throgmartin]

I did forget to mention that over the years I have seen thousands of beltline pops. In regards to the front pop's, approximately 75 % are over the drivers window. For the rear pop's, over 75 % are on the passenger rear corner. I attribute this to the house / frame construction.

Maybe it is also be that we make more right turns then left into driveways. or onto uneven surfaces. Typically, turns to the right into a driveway are tighter versus those from the left. Just a thought and a crazy theory. If we have a physics expert here maybe they can comment. I would enjoy reading comments on this. The fact remains, driver front and passenger rear beltlines are prone to popping.  

[RNMCBR]

Chris,

I think your theory about the front drivers side pops is very interesting. I am wondering whether you know what the frame looks like at the joint between the front steel frame and the rear “alumaframe”?
My coach has a persistent issue at the front drivers side upper belt line joint. Several years ago in an effort to fix sealant coming loose, I added several SS #12 screws along this joint to tighten it up. Then I cleaned the tar tape off the cap-roof joint and fiberglassed it over all the way down to the belt line on both sides. I did this on both front and rear cap joints, finished and repainted both upper ends of the coach to repair peeling clear coat. I hoped this would end the problem I’ve had with sealant coming loose on the front left corner while making the cap joints look better. It did look nice for a while. 

However, within a year I noticed the front left fiberglass’d joint cracking in the curved area from the belt line up toward the roof. There must be differential movement in this area. 

My coach has a steel frame supporting the front cap with aluminum framing from that joint rearward. I have suspected there is something wrong with this joint at the outer corner. Perhaps popped screws or fatigue-fractured aluminum framing. Whatever it is, it results in the corner of the joint being unstable. The fiberglassed joint is just not strong enough to hold it together. Anyway, that's what I’ve been thinking. 

I would like to get into this area from the inside to inspect and repair this joint but that looms as a difficult task. It looks like I would need to drop the cabinets and ceiling panels to get access to the joint. I wish I had a framing diagram showing the attachments. 

I think your idea of the frame twisting is what is causing this movement at the joint. 

I wonder whether you have ever dug into this area and have any insight into the joint structure where the steel front frame attaches to the aluminum frame. 

I appreciate any thoughts you may have on this.

Thanks, Roy

 

[throgmartin]

Roy:

The Monaco coach models differ slightly in construction on the roof and in the front cap area. Surprisingly, I have seen much more roof structure issues with the higher end Coburn built coaches then the lower end models built in Elkhart.

I have never dug into the structure, but I can tell you that I have seen issues caused by a cross brace or support beam that was missing. Monaco builds a rugged structure but there have been issues in certain areas. Roofs and the body areas in the corner of the slide openings are just some of them. Missing cross or support beams on the roof has produced sagging AC units and stress cracks around the front and rear caps on Sig's, Executives and Dynasties. You are talking about a big job tearing into the roof, either from above or below. Any welding in this area would require an experienced person who can weld dissimilar metals if there is a problem at a joint. 

All it took was a welder at the factory working with a hangover to have either missed a weld or applied a weak bead or completely forgot a support member to cause problems with the structure. Still, Monaco built some of the strongest structures on the market. Next time you are in a campground and there is dew on the side of coaches, take a walk and look at the walls on other brands. Yoiu will then see Monaco built a stout coach.

Having done inspections on thousands of Monaco's it was very easy for me to see patterns of problems on our coaches. Reminds me of a time I did an inspection on a members coach and told him I found cracks in his fiberglass roof near the TV antennae. He said he couldn't believe it. I told him I could because I have seen hundreds of these cracks and fixed several dozen. 

Sadly, our Monaco community is losing a lot of technicians who were experts with our coaches. We have seen it all, over and over again with our coaches. PJ Mcghan and Tom Bumpus are very close friends of mine and two of the best Monaco techs in the country. They left the industry and just this year I retired. There are numerous other great Monaco techs hitting retirement age. What is going to be left is young techs who rarely see these problems and know the fixies. It is scary. PJ, Tom and myself specialized in Monaco repairs and that is hard to find now.

[RNMCBR]

Thanks Chris,

I suspect the joint that is failed is between the steel front frame and the aluminum sidewall and roof framing to the rear. I think the problem is the intersection of the front cap and roof where they join the sidewall.  I expect they are bolted or screwed together and that either screws have popped or aluminum welds near the joint have failed. I agree, it would be a big job to expose that area. I will probably keep digging for information/diagrams/drawings until or unless it gets too bad to live with. I may just apply eternabond tape over the crack and watch it. Or maybe I can figure out a way to snake a endoscope in there to view the joints.

The other upper three corners of the coach seem fine, indicating to me there is something unusual on this one. 

Thanks for your thoughts and for all you do for our community.

Regards,

Roy

[RoadTripper2084]

Alright folks, my turn to share my belt-line related angst with the group.  

So when I bought the coach it had slightly popped belt-lines at the DS front, rear, and PS rear top corners such that the silicone sealant starting to fail and the belt-line was visibly separating from the sidewall. This was late fall and winter was days to weeks away so I took it to an RV shop and instructed them to fix the corners and reseal.  They were unable to secure new screws into the corners (they claimed there was nothing to screw them into that was holding), so I had them use a bunch of silicone under and around the belt-lines to secure them and waterproof them as best as could be done in a half a day's work. This "worked" until this year where the DS seam between the windshield and the driver's side wind is once again separating from the sidewall.

Having read all the advice and watched the youtube videos on belt-line repair, I purchased a number of stainless steel rivets and related tooling etc. to tackle this repair properly.  I am now working on this with a good weather window and a week off from work. 

Today, I discovered that there doesn't seem to be any steel behind the seam in question, just wood.  I was able to drill a new hole through the aluminum belt-line strip and the bit sank 1 1/2" without hitting anything harder than the relatively soft wood. Fortunately, the bit did not protrude through the padded vinyl they used on the interior of that area.

My coach is a '97 Dynasty, and is all-steel in construction (no slides).  Does this mean that none of my belt-lines are secured into steel beams, just the wood framing? ...or is it only the case in this narrow area between the windshield and side window?

They used 1" self tapping screws at the factory from what I can see. The screws haven't rusted or broken, but stripped out of the wood. It is possible the wood is water damaged and rotten.

So I have a "situation" here and a short time to rectify it.

With no steel to anchor the rivet to I was thinking of trying to anchor a larger SS screw (#10 or #12, 1") and possibly filling the holes with wood glue and some broken off bamboo skewers to add volume and strength.

In addition to figuring out how to secure the belt-line, with all the proflex all over the place there is no way I'm going to be able to remove it completely for a clean re-seal in this area, so I was thinking I could add some Butyl tape under the belt-line to provide a solid flexible sealing barrier (just in this area) and then just use Proflex as usual around the outside of the belt-line cover and hope for the best.

Edited Wednesday at 12:51 AM by RoadTripper2084

[Chargerman]

It looks like you have wood in there but the beltline screws must be missing it or are too short to get a good grip. If you have some that are mousing the wood I would pull off the trim inside and add another piece of wood for the screws to hit clearly there isn’t any metal there so the rivets wouldn’t work

Edited Wednesday at 01:04 PM by Chargerman

[jacwjames]

My suggestion would be to remove the drivers side window and take a good look at the area.  If the aluminum extrusion doesn't have something solid to fasten too it will be difficult to seal. 

I'm almost positive there is metal behind there, I've had my window out to fix the fogging.  Not hard, but will probably take two people,  I did mine myself but not recommended. 

I had to repair a large area of delamination on the passenger side rear where the roof and rear cap come together.  I think the body flex broke the upper beltline seal and let water get in.  I removed the beltline to repair the delam with epoxy then reattached, I had metal behind the aluminum.