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kartfreak · 06-10-2015, 05:48 PM

I've got a 2013 Storm 28 with 18000 pound Ford chassis. Picked it up in Florida several months ago with about 13000 miles, and noticed the outside of both front tires looked to be wearing more than the rest of the tire. Tires were a bit low on air, so bumped them up a couple pounds over recommended. I.ve put on about 4000 miles, and the outside edge of both are clearly wearing rapidly, mainly the right side. I thought I would transfer them to the back, but guess that's a no-no after reading the book. Is this common for a straight axle? My old P30 had about 35000 on the tires before you could even see any wear pattern.

Skip426 · 06-10-2015, 06:02 PM

Sounds like it's time for an alignment .
Chassis is aligned before the body work is added, and the alignment should be checked at the first service, sounds like yours wasn't done.

Question; Which book says no to the rotation ?

twinboat · 06-10-2015, 06:08 PM

Check out the post about "King Pins" on your year, Ford MH.

Seems to be a trend starting.

Hikerdogs · 06-10-2015, 06:37 PM

As mentioned before the end customer is supposed to have the front end aligned with all the gear, fuel, and water that they will normally carry when using the motorhome. If you're already experiencing tire wear problems it's likely the final alignment was never done.

Ford aligns the bare chassis before it's sent to the body builder. The body builder is supposed to align it again after they add the weight of the house, and the customer is supposed to align it a final time when loaded for travel.

alank · 06-10-2015, 08:31 PM

We had the same unit as you have for a short period and the toe-in was set at 3/4 inch, tires were showing wear right away and drove terribly. Ford doesn't align them because the coach builder is going to put a big load on the chassis. Chassis builder doesn't align them because you are going to load it down so they put a sticker on the coach to tell you to align it.

If you can get a proper alignment (which is hard to do) you'll be amazed how much better it handles. Get it done.

kartfreak · 06-11-2015, 12:11 PM

Guess I'm headed to the alignment shop!

Skip, the Ford chassis book says to only rotate tires from side to side, not front to rear. That is completely backasswards from what they have always told us about radial tires: always keep them turning the same direction. So??
I read the king pins thread, interesting, but not my problem. I have no handling complaints, this thing is a million % better than my Southwind P30. I can actually relax while driving this one!

Statgeek · 06-11-2015, 12:16 PM

Alignment issue for sure. I had the opposite happen in my (brand new) DP, with the inside edges of both tires wearing out prematurely at month 13.. I had to buy two new tires and pay for an alignment... most RV manufacturers run away from alignment issues. They can point the blame to the chassis (who will point the blame back to the RV manufacturer), and both of them will point the finger to the owner, claiming improper tire inflation and/or overweight.

Hikerdogs · 06-11-2015, 12:55 PM

Quote:

Originally Posted by kartfreak

Guess I'm headed to the alignment shop!

Skip, the Ford chassis book says to only rotate tires from side to side, not front to rear. That is completely backasswards from what they have always told us about radial tires: always keep them turning the same direction. So??
I read the king pins thread, interesting, but not my problem. I have no handling complaints, this thing is a million % better than my Southwind P30. I can actually relax while driving this one!

Ford recommends side to side rotating (if you choose to do it) because they feel the wear will be different on the front axle than the rear. When rotating corner to corner you'll have 1 tire from the front and 1 tire from the rear in each rear axle position. If the tires haven't worn at the same rate the larger diameter one will carry more than half the weight. If you're at the max GVWR you'll likely overload the larger diameter tire. When rotating side to side the same pair of tires will always be together on the rear axle. Since they started as a pair they should wear at the same rate.

Some radial tires are single direction tires while others are not. The Michelins on our Buick are single direction tires and as such aren't supposed to be rotated side to side. They have an arrow molded into the rubber indicating the direction they should rotate. I am not aware of any RV radials that are single directional.

Gary RVRoamer · 06-11-2015, 01:40 PM

I think Hiker dogs pretty well covered the front-rear rotation question, but I'll add that it is not really a concern when the tires are relatively new or all are known to be worn to about the same degree. It takes a sizable difference in wear to make a difference on a dual mount. Besides, you can mount both front tires as one pair - there is no rule that says you have to rotate to the corners if you have reason to do differently. The corner business is just a standardized method for distributing normal wear across a set of 6 or 8 tires, but you can do differently if you choose.