My wife and I have decided on where we will get (oh wait, we already ordered it) our next 5th wheel, and I am happy to report that it will be our third Montana. We have not had a major problem with either of the previous two models, but have had minor problems which can probably be attributed to a seven to eight ton house bouncing along on the always well maintained highways and byways of our land (sarcasm intended, particularly in reference to the WV Turnpike!). 90% of problems, I address myself (in warranty or out), the rest can be handled by a competent service department. Keep in mind that the primary use of this forum is to report problems so members can receive advice on how to remedy their problems. While these problems (ours included) are obviously of primary importance to the members who are affected, they are not and should not be construed as being indicative of every rig manufactured by any company out there. With regards to the OP, I have seen this problem in the past (can't remember if it was on the MOC, though), and if my memory serves me correctly it was caused by a structural fault in the slide itself. Keystone-Montana should step up to the plate to resolve this. The solution needs to address the slide itself in my opinion in addition to the cosmetic repairs that will be needed. The cosmetic repairs if properly done will be stronger than the original outside walls of the rig. The interior cracks will have to be remedied by replacing the wall boards. Replacing the wall boards will also reveal whether the structural integrity of the exterior wall framing is to blame.
Bingo