Over Inflate Tires when storing trailer ?

[MikeD]

We are getting our trailmanor in about a month, and I've been working on coming up with a set of checklists. While working on my checklist for winterizing and storing the trailer, I came across this Goodyear webpage which gives Storage Information for your tires.

On this page, it says that you should inflate your tires to the "recommended operating pressure plus 25%, ensuring that the rim manufacturer's inflation capacity is not exceeded".

Here is website: http://www.goodyear.com/rv/tirecare/maintenance.html

I haven't seen any other references to over inflating your tires for storage on this site. Has anyone else done this ? Any recommendations ?

thanks, MikeD

[RockyMtnRay]

I haven't done this but it does make sense for two reasons: (1) it compensates for the loss of pressure that will occur because of lower winter temperatures and possible very slow leakage that many tires have; and (2) it reduces the sidewall bulge above the tire contact point. Reading between the lines in the linked instructions, it is this sidewall bulge that's most susceptible to ozone cracking (which leads to premature tire failure).

However, I note that Goodyear recommends the over pressure technique only if the trailer has to be stored with its weight on the tires. I currently have the front of my trailer setting on the front scissor jacks so the tongue could be folded. I'm thinking of cranking down the rear scissor jacks to raise the rear enough that most, if not all, of its weight will be off the tires. It's on a level concrete garage floor so there shouldn't be any frame twisting if I am careful about cranking down the rear jacks by the same amount. Anyone else doing this?

[RockyMtnRay]

Update to idea of using rear jacks to remove weight from my TM's tires. Just remembered I have a pair of jack stands that can be adjusted to 3 different heights (using a pin). These stands in conjunction with a 2X4 will be tall enough to raise the rear of the TM about 3 inches...enough (in combination with the front scissor jacks) to mostly (if not completely) remove its weight from its tires. The jack stands, being of exactly the same height, also won't introduce any twist into the trailer's frame.

Ray,

I wouldn't recommend using your TM's scissors jack stabilizers or any jacks to elevate the ends of your TM trailer in order to take the weight off the tires. This appears to be false economy because in trying to extend the life of the tires you may be causing damage to your trailer's frame. Engineeringwise, the steel frame of your trailer functions as a beam. Most of the load on it is concentrated near its center and, therefore, the axle and tires are placed closely underneath most of this load. This design relieves the stress on the frame under ordinary static and towing conditions - and allows the framework to endure the additional stresses caused by bumping along on rough roads, or excessive weight that you may have put into the trailer. If you elevate the ends of the trailer with the stabilizers or jacks and raise the tires off the floor, you're now supporting the "beam" only at its ends. The beam or framework then will be subjected to its greatest bending loads, and, may be permanently deformed or fatigued.

The stabilizers are only for "stabilizing" the corners and to reduce the trailer's movement when you walk around inside of it or the wind hits the outer walls. It's probably okay to use the stabilizers temporarily to raise a flat tire off the ground if you don't have a jack to put under the axle. Raising the tires off the ground over a long term, however, might do significant damage to your trailer's framework.

[RockyMtnRay]

Well, Larry, I think we first need to move away forever from using the term "stabilizers" when discussing any of the newer TMs (those made with the scissor jacks) such as mine. My manual (2002 edition) no longer has any reference whatsoever to "stabilizers"...they're now solely referred to as "scissor jacks". Furthermore, it clearly states "use the rear scissor jack on the low side to level the trailer side-to-side" (page 12). My trailer has jacks; it does not have stabilizers. The word "stabilizer" (and its associated limitations) is not even part of my TM vocabulary.

It seems to me that Mr. Hulsey (a PhD engineer) (or any other of TrailManor's engineers) do know what they are doing and would not have written that part of the manual (or approved the inclusion of it) if they didn't have complete confidence in the rigidity of the TM's frame to handle loading placed well behind the wheels. Similarly, I seriously doubt they would have approved the use of the swing-away tongue if they didn't have confidence in the use of the front scissor jacks to support the trailer on a long term basis when the tongue jack is raised so the tongue can be swung for storage.

Therefore, I have total confidence in the strength of the TM's frame to remain longitudinally unbowed no matter whether I have it setting on its wheels or setting for 6 months on its rear scissor jacks (which are only about 3 feet behind the axle attachment points anyway). I do recognize that the lateral frame members are not as large (or stiff) as the longitudinal members, so I will attempt as much as possible to use identical height lifts on each side to reduce any torsional forces (particularly since the front of the TM will be sitting on its jacks and not on the tongue).

Your concerns may be valid for your '99 model. I respectfully disagree that they are valid for my 2002 model.

Ray, you and I are talking about two different things. My comments were directed at what I consider to be a harmful suggestion to elevate the tires completely off the ground with all the stabilizers (or jacks) while you're now referring to supporting the front of the trailer with the front corners' jacks or leveling the trailer with the jacks. In both of the situations that you describe, the tires (and, therefore, the axle) continue to bear part of the weight of the trailer. I agree that these uses of the jacks will not harm the trailer's frame. What I suggested is that it is harmful to the trailer's frame to elevate the trailer's ends with all the jacks to the point that the weight is taken completely off the tires. This is analogous to removing the center posts of the beams in a building and allowing the end posts to bear the weight of the roof and ceiling loads. In time the ceiling and roof will collapse. Likewise, in time you may damage the trailer's frame.

I appreciate the fact that Bill Hulsey is an engineer who knows what he's doing. As a design engineer myself with extensive past experience in designing structural steelwork: elevated platforms, railroad trestles, steel buildings, etc., I am giving you the kind of advice that all design engineers would agree with. Mr. Hulsey can confirm the wisdom of my advice if you want to ask him. ??? ???

[RockyMtnRay]

No, Larry, we are talking the same thing...using the rear jacks to support the back end of the trailer for an extended period to totally (or at least mostly) remove the weight of the trailer from the tires. I knew I shouldn't have tossed in that mention of using the front jacks...it just confused my main point.

I remain completely confident that based on TM's clear instructions to use the rear jacks for leveling the trailer, it is perfectly safe to use those jacks on a very long term basis (many months) to support the rear of the trailer during storage. Given the litigious age we live in, if they had meant their instructions to be limited in time (e.g. Don't do this for more than 3 days or your trailer will be permanently bent), I'm sure they would have so stated to preclude legal liability.

But to remove any ambiguity about TM's design limitations vis-a-vis long term use of the rear jacks as support for the rear of the trailer, I will call TM in the next day or so to get the official opinion. My bet is they'll say it's no problem at all but I will report whatever they say to this forum.

[Bill]

Ray and Larry -

I'm anxious to hear what the factory says, either way. But either way, are we making this more complicated than it has to be? Why not just put your bottle jack (you do have one, right?) under the frame just behind the wheel, lift to the desired height, and put some wood blocks or a jack stand under the frame (not the axle!). Repeat for the other side. If desired, lower the stabilizers - as stabilizers - and you're done. The weight is supported where it was designed to be supported, the weight is off the tires, and it's easy!

Bill

Reason prevails, Bill, I think you have the most level head of all of us.

I could be wrong, but I thought trailer tires were specifically designed to bear extended "parking" time.....made of different composites, sidewalls, etc.....Than regular tires are...........That's why we buy them for our trailers.....(opps! different topic!).......again, just a thought......

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