I like to believe that I am pretty knowledgable on some subjects. Certainly when it comes to bolting wheels onto vehicles of any kind I have a lot of experience.... (I have made my living as a mechanic and now the owner of a shop that specializes in European auto repair). Anyway I have bolted on a lot of wheels in my day.
Some of you may have read my thread on the Marathon tires I have been carefully monitoring the tires for flaws from the moment they were new. Recently I discovered what I believe is a failing tire and have decided to replace the tires with Michelins.
In my quest to further isolate myself from tire woes I also decided to install a Dill pressure/temperature monitor system.
Another thing I investigated was reported lack of balance of the Dexter drums.
Andy at Inland RV has mention this before and I was skeptical, I had to see for myself....
Holy cow!!! These things are gross! I took the step of balancing my drums so that my wheels can now be balanced off the rig. This will be the subject of another post!
My final modification was to retrofit shocks to my Airstream as I really want to cover the bases here.
I began by mounting my new tires on the rims Airstream supplied with the trailer new, Sendel S20T's. I like the look and wanted to keep this wheel.
Now all that is left is to balance and check RoadForce numbers to verify that there are no problems. Here is the moment things begin to unravel!
A fussy balance takes about 5 minutes to set up. A RoadForce adjustment can take 15 or so minutes as a dismount is required but with quality tires this is seldom necessary. As part of a fussy balance one of the things a mechanic does is to verify that the rim is centered on the balancer. A procedure is run and once verified the balance can be made.
On the wheel that had the good Marathon (right side of the trailer) I could not pass the centering check. No matter what combination of lug-centric set up I used, no matter what I tried. The result was that the balancer began "chasing weight" (more about this later). I became annoyed and spent hours trying to get a perfect looking wheel/new tire to balance. I could not! Finally I simply took the wheel and tire to a tire shop explained my problem and asked them to show me what I was doing wrong. They could not get good results either. Critical inspection finally revealed that the tapers in the lug holes did not appear to be centered. Almost like they were not machined correctly or perhaps they were run loose??? The lugs have always been tight when I dismounted the wheels. I simply do not know what happened. (The Hunter Equipment representative is going to stop by Tuesday to see what he can determine, stay posted). Anyway that wheel is no longer something I trust.
Chasing weight is a condition were a wheel is balanced and a check spin is performed to verify that the balance is fine. After passing the check spin (balancer calls for no more weight or says “OK”), the “balanced wheel/tire” is removed from the machine and then re mounted on the machine for another check. A balanced assembly is balanced, it needs no weight but upon checking the second time the balancer calls for weight to be added. Obviously something is wrong with the balancer or the procedure.
Full of self doubt I recheck the Marathons by remounting them on a known good truck wheel to see if the decision to abandon them was valid. It was! Apparently the out of round lug pattern did not impact the RoadForce measurements very much. When I say out of round I mean by thousandths of an inch, just enough to prevent the wheel from bolting to the hub or balancer the same way every time.
Now to look at wheels. I really do like the look of the Sendel wheel but now I am beginning to wonder exactly what happened. In my search the first thing I discovered is that Sendel no longer has a listed telephone number. They also have not answered my email for information about their wheel. Are they still in business?
I then found a very interesting website of a trailer wheel manufacturer, HiSpec.
HiSpec Wheel & Tire, Inc. - The Safety Wheel
There is some very interesting reading here! In the end I purchased their Type 3 wheels that have the same appearance of the Sendels.
1.Balancing a tire on an Airstream separately is useless if you do not first balance the drum or alternatively balance the wheel on the drum.
2.Dismount the wheel/tire from the balancer and remount for a balance check, you may be surprised!
3. Wheel torque is important, re-torque is more important!
Look carefully at those wheels and inspect the lug bores for signs of loose running.
4.I really am impressed by the information on the HiSpec website. I called and easily got through to an engineer who verified my concerns about my current wheels and promised their wheels would be better in this regard (all without bashing the competition)
5. I knew less than I thought....