Foretravel Owners' Forum For owners and Fans of Foretravel Motorcoaches September 08, 2025 ...

Underbody/ bulkhead joint

May 26, 2025, 03:17:32 pm

Beneath at the rear bulkhead there is a joint with a strip of metal. This metal strip is deteriorated an 3/4 of it breaks off and a joint is visible.
Should I remove the last 18" ?
Do I need to install a new piece of trail using 1/2" aluminum angle?
I have removed all the loose silicone, wire brushed it removing any loose rusting crud. Now intend to spray with corrosion technologies rust remover.
Should I then just paint it and seal with a polyurethane caulk?
Thanks

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Re: Underbody/ bulkhead joint

Reply #1 – May 26, 2025, 03:34:27 pm

Yes, I would remove the remainder of the rotted strip-- doesn't appear to do anything positive in the condition it is in.

Then be sure to seal the joint using something that is a little flexible.  So polyurethane would work.

How many Roloks were broken? Did you replace the Roloks? With what?

What was the condition of the transverse box beam into which the Roloks thread (just in front of the angle where you see the Rolok bolt heads)?

I also seal around the heads of the Rolok bolts with automotive undercoating as that is another point of water entry.

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Re: Underbody/ bulkhead joint

Reply #2 – May 26, 2025, 03:41:51 pm

Hi Brett, the roloks appear ok, I did not try tightening them for fear of damaging the anchor points. I don't appear to have any rust or movement. The box beam is not visible: the underbelly is all secure

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Re: Underbody/ bulkhead joint

Reply #3 – May 26, 2025, 03:49:55 pm

With the way the metal strip is degraded, I would be very surprised that the box beam immediately in front of that strip is OK.

And, you hurt nothing by trying to tighten the Roloks.  They are grade 8 bolts.  If they will not hold, say 20 lb-ft, they are sure not going to hold the coach together. 

What I have found is that they will either hold that low amount of torque, or will break off a couple of threads from the head with heavy rust at the break indicating that it has really been broken for a long time. Have never seen a "fresh break".

There is no way you could "twist the head off" that grade 8 bolt at 20 lb-ft.

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Re: Underbody/ bulkhead joint

Reply #4 – May 26, 2025, 03:58:36 pm

Ok will get torque wrench out, thanks

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Re: Underbody/ bulkhead joint

Reply #5 – May 26, 2025, 05:16:44 pm

Problem:
I have one rolock on the rear bulkhead that twists at 20lbs: it is the most outside bolt on the passenger side. What do I do now, is this an easy fix or a trip to Nag?
I have read numerous articles here but they are discussing how it should not be built, any suggestions for repairing?
Can I remove the rolock and insert a new one?

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Re: Underbody/ bulkhead joint

Reply #6 – May 26, 2025, 08:09:02 pm

Bite the bullet and through bolt the front and rear bulkhead.
If you were to dig into it I'm sure you will find the original Rolox bolts are broken or severely rusted and compromised.

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Re: Underbody/ bulkhead joint

Reply #7 – May 26, 2025, 08:10:35 pm

So, only one Rolok would not torque up-- that is great.

Is the "floor in front of that location open or already sealed?

If open, a bolt and nut with appropriate rectangular washer is the "go to".

Have you pulled out the offending Rolok?  Are the threads in poor condition (meaning a new bolt may fix the issue) or are they in good condition (meaning the box beam into which it screws) is degraded.

Send me a PM if you want to visit by phone.

Brett

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