Forum Discussion

Desert_Captain's avatar
Desert_Captain
Explorer III
May 21, 2016

Re securing the cab/cabover joint/seam

Like most Class C 's manufacturers, Nexus uses screws to connect/secure the cabover to the top of the cab itself. The problem is that over time, miles and having hit just about every pothole between Arizona and Maine those screws tend to work loose or fracture.

This leaves a bit of movement between the cabover and the cab. After a couple of years this movement became more pronounced so I pulled the plastic molding down and tightened every screw, replacing a few with larger and longer. This band aid solution worked for a year or so but was not the long term cure I needed.

I ordered the three replacement plastic molding pieces from Nexus and ended up with three additional pieces that are enough to redo the entire cab (I'll save those for some future needs).
About $40 worth of hardware and couple of additional tools and I was ready to go to work.

Taking down the molding and opening up the seam/joint was straight forward enough and happily all of the existing screws came out without complaint. Using a Cobalt drill bit (which went through the steel like the proverbial hot knife through butter), I re drilled each hole going all the way through/out the top. I replaced every screw with a 2" #10/24 SS machine screw (with large round flat heads), and added flat washers and lock nuts to the top.





Before I could torque them down I had to place clamps on either side of the new bolt to tighten/flatten the steel top of the cab. I worked from back to front alternating from right side to left finishing in the center of the cab. Once they were all torqued down I used a hack saw to trim off the excess bolt right at the top of the nuts.

The last step was to install the new molding and for good measure I replaced all of those screws as well. Buttoned everything up and took the coach for a test drive and Wow! what a difference. There is zip, zero, nada, no movement of the cabover with not a squeak top be heard.



Structurally this is a 1,000% improvement from the original, perpetually loosening screws. I know through bolting takes more time/money but it is definitely the right way to go and frankly I was disappointed that Nexus used screws in the first place. I can't see how those lock nutted bolts will ever loosen up but only time will tell.
Class C
  • coolmom42's avatar
    coolmom42
    Explorer II
    May 22, 2016
    Desert Captain wrote:
    coolmom42 wrote:
    As a potential class C owner, I am interested in this repair as it seems to be a common problem. I see the washers and lock nuts sticking up on the upper side of the cabover. It looks like a very effective repair, but don't they damage the cushion that fits in the cabover?

    *just a little confused*


    Look closely at the last picture. The plastic molding slides over the top of the nuts and the cabover mattress lays on top of the plastic molding. Most Class C manufacturers use basically the same construction technique as Nexus, nothing unusual there. Here is another pic that may help....



    As you can see the left piece of molding is in place with the decorative buttons covering the screws that secure it to the seam. The center piece of molding is overlapped by the left hand piece and has not been drilled (note the dimple on the left side), but both pieces are covering the nuts on top where the 2" bolts protrude. hope this clarifies.


    If you are wondering if you have some movement, and you probably do, place your hand firmly on the cabover while driving down the road. You may be surprised at how much the cabover moves. It is fairly easy to troubleshoot, you just have to strip away whatever covers the seam and then check the condition of the screws (loose, broken etc.), and then take the appropriate corrective action. As noted larger/longer screws tightened up is at best a temporary solution.

    Also when you open things up look closely for any evidence that water has gotten in/migrated and take the requisite corrective action there as well. I had zero water intrusion.

    Hoping that the use of through bolts, lock nuts and washers will solve the problem.

    :C


    Thanks! I see now that the molding is thick enough to cover the nuts etc. Makes sense. And that is a nice repair job.
  • klutchdust's avatar
    klutchdust
    Explorer II
    May 22, 2016
    My Itasca Cambria had one of the angle supports they use come loose from the top of the cab. I re-fastened it with some epoxy and also eliminated some squeaks by re-tightening all screws that I could see into the wood frame them applying a thin spray of foam and that made a difference.

    You did a nice job and the pictures are a great help.
  • Desert_Captain's avatar
    Desert_Captain
    Explorer III
    May 22, 2016
    coolmom42 wrote:
    As a potential class C owner, I am interested in this repair as it seems to be a common problem. I see the washers and lock nuts sticking up on the upper side of the cabover. It looks like a very effective repair, but don't they damage the cushion that fits in the cabover?

    *just a little confused*


    Look closely at the last picture. The plastic molding slides over the top of the nuts and the cabover mattress lays on top of the plastic molding. Most Class C manufacturers use basically the same construction technique as Nexus, nothing unusual there. Here is another pic that may help....



    As you can see the left piece of molding is in place with the decorative buttons covering the screws that secure it to the seam. The center piece of molding is overlapped by the left hand piece and has not been drilled (note the dimple on the left side), but both pieces are covering the nuts on top where the 2" bolts protrude. hope this clarifies.


    If you are wondering if you have some movement, and you probably do, place your hand firmly on the cabover while driving down the road. You may be surprised at how much the cabover moves. It is fairly easy to troubleshoot, you just have to strip away whatever covers the seam and then check the condition of the screws (loose, broken etc.), and then take the appropriate corrective action. As noted larger/longer screws tightened up is at best a temporary solution.

    Also when you open things up look closely for any evidence that water has gotten in/migrated and take the requisite corrective action there as well. I had zero water intrusion.

    Hoping that the use of through bolts, lock nuts and washers will solve the problem.

    :C
  • coolmom42's avatar
    coolmom42
    Explorer II
    May 21, 2016
    As a potential class C owner, I am interested in this repair as it seems to be a common problem. I see the washers and lock nuts sticking up on the upper side of the cabover. It looks like a very effective repair, but don't they damage the cushion that fits in the cabover?

    *just a little confused*
  • Robocop's avatar
    Robocop
    Explorer
    May 21, 2016
    Every day is a new day as it relates to issues, regardless of manufacturer. Your detailed explanation as to the repair process was great.
  • j-d's avatar
    j-d
    Explorer II
    May 21, 2016
    A little surprised, from what I hear of Nexus, too. So far, our Jayco hasn't exhibited any cab/cabover issues. Doggone, now I've gone and said it...

    Was ready to blow the screen up to see if you'd used elastic lock nuts. Of course you did! Quality Job! Use it in good health.

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