Loose bolts

[mazeeff]

I have owned our 2005 3255RL for about six months and figured it was time to snug up all the undercarriage bolts/nuts. I was shocked to find 90% of them loose. Some were so loose that they were spinning free! The large bolts securing the slides were the worst, but most everything was loose. I need some advice on one thing I found that did not look right at all. I was going to fix it, but thought I would check here first. The hydraulic ram that operates the big slide has a threaded end that passes through the steel bar welded to the slide frame. The threaded rod has two large nuts on one side, and one large nut on the other. The double nutted side appears to be the adjustment side, and the single nut side simply keeps the rod rigidly attached to the slide frame. On mine the single nut is about one inch away from the steel bar. This causes the rod to move about an inch prior to moving the slide. The rust on the rod, suggests that it has been this way for quite some time. The slide works perfectly, but I want to fix this, unless there is some reason for the gap. Any ideas?

[azstar]

Hello Mike,

I too have seen this on our Rig. I believe the gap is to allow some flexibility as the slide reaches it's final seating either in or out. If the nuts were to be clamping the piston rod securely to the frame this could put a stress on the piston shaft and possibly eventually cause a crack, either in the shaft thread just behind the nuts or a crack in the frame.

No slide goes out or in perfectly. Does that make sence?

Happy Camping

[mazeeff]

Steve. I understand what you are saying, but I'm not sure I agree. When the slide is being pushed out, the gap is on the outward side. The gap only allows for further movement outward. When fully expended, the gap can not be decreased, and therefore plays no role. The same is true when the slide is retracted. If I tighten up that nut when extended, I can't imagine any additonal strain on anything. The system just freewheels when it hits the stops after extending or retracting. The fact that yours has the same gap, makes me wonder however, if this is there for a reason. I guess if a few more folks can check theirs, I'll conclude it is planned that way!

[azstar]

Mike,

Actually in a perfect design your are correct. There would be no Stress, but this would require a perfect alignment of the piston to the object it's pushing or pulling in all planes.

In the Aerospace Bus. this was a common problem which we handled by ball mounting both ends of a piston. In the Aircraft Engine there is no place where we could leave any slop in a system like this, it had to be rigged solid and to prevent a failure we had to use ball mounts. An easy and cheap way to get around using ball mounts would be to leave a gap as you describe.

Man I love this Forum. Haven't thought about this stuff for a long time since I retired 4 years ago.

Happy Camping

[mazeeff]

OK. I now understand the logic. When I was looking at it, I thought the outside nut looked like one of those nylon embedded nuts (not sure what they are called!). That would make sense, if the nut was not intended to be snugged up against the mounting bracket.

[azstar]

Good on ya Mike,

There called "Nylock Nuts"

Happy Camping

[stiles watson]

Thank you for this discussion. You have, once again, answered questions I didn't even know to ask. I will be checking the torque on those nuts, bolts, and screws.

[MIMF]

Hey guys, don't touch those nuts unless you want to rip the facias of the rooms!!!!

You will always notice a gap between those nuts on the cylinder shaft. The two back nuts are jam nuts and are set so that when the room is in the full out position and sealed, the piston inside the cylinder is bottom out. THE CYLINDER CAN NOT PUSH THAT ROOM OUT ANY FURTHER!!!! The same applies coming in. The piston inside the cylinder can not pull the room in any further because, it is bottomed out at the back of the cylinder. All rooms are equipped with cylinders with a slightly longer stroke than what the room actually can move. That is why the gap. Some set-ups on other coaches, the cylinder shaft may move several inches before it engages the bracket to move the room. Can you imagine what would happen if the cylinder stroke was too short??

DO NOT MOVE THOSE NUTS! Not until you talk to me first.

[mazeeff]

I left the "NUTS" as is! Thanks to this forum, I checked here first. A couple of years ago, I would have gone ahead and snugged up the nuts, and damaged the unit! This forum has saved me a lot of pain and suffering!

[CRUZIN 2]

MIMF

I'm glad you answered, and said not to move those nuts. I couldn't have answered as good. GREAT JOB

Larry & LaVonne

[azstar]

Thanks MIMF,

I completely agree. Don't move the Nuts.

However I must respectfully disagree with the methodology of bottoming out a Hyd. Cylinder to control a final positioning. I know this is a pretty low tech application and seems to work so I guess it's OK.

Happy Camping

[Thunderman]

Do you ever lubricate the "shiny" shaft coming from the cylinder or just wipe it clean? Thanks!

[hodag]

we have an '03 3295 that i was able to tighten and keep tabs on the bolts on the under carriage. the u bolts that hold the axle to frame took more turns than i would have thought. i have box of spare shackle parts,haven't done anything with those yet. regarding space between nuts on shaft to slide, ours has about 1" play. within the past week there was a post about those bolts at each end of the square tube that runs the slide in, told size and keep some spares. i bought 6, now have 5 as found rear bolt on dinette [largest slide] sheared. just the head end of bolt holding in. noticed the slide coming in a little jercky and uneven so after reading post i checked out the bolts. if we own these things it doesn't hurt to crawl around under and on top of them.