RL,
Thanks for the reply and quite a bit to ponder. Here are my initial
reactions:
I had NO tire complaints until this last set of Marathons which were
installed in '04. I have used them since the '80's and I considered myself a
loyal consumer until last week.
One tire showed scalloping...possibly an unbalanced situation.
Both tires showed signs of what I believe to be belt/tread issues as well as
side wall issues. I do not see how two humps all the way around the
circumference of the tire (with pronounced low spots on both sides and
center of the tread) can be anything other than belt issues...but I admit
that I am not a tire expert.
I have to replace a few rivits after almost any trip of length. This has
been happening for decades. I suspect that the drums may have been out of
balance all these years and we did not know it. I have ridden in the trailer
on ocassion just to see how it rode. Probably never over 45 mph. In hind
sight I should of done this on an interstate at higher speeds, just long
enough to be satisfied that it was riding smoothly.
In '03 we remounted the springs on top of the axle to gain much needed
ground clearance. This lifted the trailer an estimated 4 to 6 inches. Enough
that we carry around a box to use as an additional entry step. I have
noticed no difference in how the trailer handles because of this
modification. If I were to do this over at this time I would just get a
straight axle. This would half the additional height that remounting the
springs gave us and still be high enough to get in and out of most driveways
without scraping the bars installed to protect the added sewer piping under
the rear of the trailer.
As appliances are replaced the newer ones are lighter weight. We weighed the
trailer and the side to side balance is very good, less than 100 pounds
difference when loaded. We did add a wash water tank. It is mounted mid way
between the axle and rear bumper, as far forward as the frame would easily
allow. We attemp to never travel with water in this tank. The spare tire is
mounted on the rear bumper. I thought that this was a factory option however
a 1960 picture has surfaced and no spare is on the rear! It lived just
minutes from the factory and it was always taken there for service so I am
certain that the factory did that modification. As a result of the extra
weight on the rear we do need to travel with some water in the fresh tank to
keep the tongue weight near 10% of total.
Location of the axle...I have noticed that in general the earlier the
trailer the more central the axle(s). As the 60's and 70's came along the
axles tended to migrate rearward. I believe that this was in response to the
realization that 10% tongue weight was optimal for handling and the advent
of weight distributing hitches that permitted the heavier tongue weights
without overloading the rear axle of the family car. And lets not forget the
interstate system which encouraged faster towing speeds. In the early 60's
it was the general rule in WBCCI to never tow over 50 mph. I did get the
opportunity to inspect up close a '60 Overlander with dual axles. The second
axle was simply placed behind the first. The lead axle of the duals is in
the same position as the single axle.
Scott
> Scott - in thinking about your tire scalloping situation - here's
> something to ponder:
>
> When your (single axle) trailer was new - it was available in both single
> axle and twin axle formats.
>
> As you've mentioned - 26' for a single axle is a lot of length for a
> travel trailer to begin with. Add to that how the factory tuned it and
> how the owner loads it and maintains it and tows it and you've got even
> more to take into consideration.
>
> In looking at RJ's photos from '55 thru '60 - it looks to me that
> depending on what year the Overlander was offered (single axle version)
> there may have been year to year differences in the actual location of the
> axle when looking at the frame/shell. Some years appear to have the
> single axle placed in the very center of the shell (fore and aft) and some
> years appear to have the axle mounted rear-of-center when looking at the
> shell of the trailer from the side.
>
> If so - these changes very likely may have had to do with (among others)
> the year-to-year weight changes in kitchen/bath locations etc.
>
> Depending on how these single axle models have been remodeled and updated
> over the years - (weight shifted) - this could have serious balance
> implications on the original factory design for the frame/shell/axle.
>
> I'm pretty sure your family one-owner Overlander is probably still in it's
> original layout etc - but if you've made any weight distribution changes
> (permanent trailer components) - you might consider this as one reason for
> "odd" tire scalloping. I say "odd" - if after all the new service work
> you're doing is completed and all the "usual suspect" issues have been
> confirmed as being "not suspect".
>
> The single most interesting class I took years ago in Auto Mechanics
> school (Spokane Community College) was the "drivetrain and driveline"
> vibration class.
>
> The single most important thing I learned is that just because there is a
> vibration/wear issue present in a vehicle - you never should assume the
> vibration/wear issue is being caused by something obvious.
>
> Sometimes the source(s) of vibration/wear issues end up being no where
> near the point of actual wear....
>
....It might be worth comparing the axle location on your 1960 Overlander
with other single axle Overlander owners and then comparing tire wear
stories.
>
> Also - you might want to think about your tire wear issue in terms of what
> was normal for tire wear when the trailer was new (not now). In
> otherwords - there weren't any radial trailer tires available - and owners
> may have been changing their bias-ply tires more often. If not for good
> measure (like today) - then maybe just because they were wearing out
> faster.
>
> Maybe your trailer axle design is simply meant for "more often tire
> replacement"....due to the individual reality of how your specific trailer
> bounces, wiggles, shimmies etc...etc...etc. regardless of how many ways
> one balances everything out. Modern tires are no doubt generally better
> than what was available in 1960 but...they may not be better for your
> specific trailer. The modern tires are possibly intended to match up with
> modern chassis designs - while your old chassis may simply be overworking
> them...no matter how well they are made.
>
> Good luck and travel safe. RL