A few posts back, I discussed the importance of using forged aluminum wheels as opposed to the less expensive, weaker cast aluminum wheels offered in the aftermarket and as standard equipment on some RV products. Almost as if to illustrate the point, a gentleman brought in a huge triple-axle fifth wheel trailer that had experienced a critical wheel failure. We’ve all heard of tire blowouts, but in this instance it was a wheel blowout; the explosion was so powerful, it blew the outside lip right off the wheel. He told me that the tire came off the rim completely and travelled down the highway.
Closer examination revealed that the wheels were rated to 3,500 lbs. and 110 psi, and the other Goodyear tires were inflated accordingly. Unfortunately, the manufacturer of the trailer had tried to save money using cast-aluminum wheels, which were made in China. From my experience, Chinese manufacturer ratings don’t necessarily mean much when the wheel is loaded to its maximum. Besides that, castings just don’t have the same strength as forgings-the forging process creates a much denser molecular structure.
Having experienced such a violent wheel failure, you would think that the owner would want to make sure it didn’t happen again. But instead, he wanted to replace the cast wheel with another one, or failing that, steel rims as a replacement. My concern was that the same thing would happen with another cast aluminum wheel, and we have seen inexpensive steel wheels crack before. That’s why we recommend a forged wheel like an Alcoa or Accuride-they’re a lot more expensive, but in a product like this, you get what you pay for.
The tires were also exhibiting unusual wear patterns. After checking it out, we found that this trailer’s alignment was the worst of both worlds-it was both toed in and toed out too much. The front axle was toed in ¼ inch, the middle axle was towed out .18-inch, and the rear axle was toed out .26. In addition, the middle axle’s thrust angle was off by .23 of a degree, and all three axles had negative camber (where the top of the tire is leaning inward), which, when combined with the toe-out condition, will wear out a tire very quickly. When we were finished with the trailer, the toe in was set at .07-.09 inch (some toe-in is necessary in the static condition so that it is at or close to zero in the dynamic or moving condition), and the camber was set at between zero and .02 of a degree. The trailer will now have a lot less resistance going down the road.
An alignment job like this takes several hours to perform, and the customer was uncertain about spending that kind of money. However, it’s important to take into consideration that the Goodyear tires on this particular trailer cost $350-$400 a piece with mounting and balancing, and there’s six of them. And don’t forget that misalignment causes drag, and drag reduces fuel economy.
The customer also indicated that he had one disc brake caliper on the trailer that was not working. He wanted to have it rebuilt, but there was no kit available, so I offered to order a new caliper for him, which might take a few days. He declined. So in the end, he drove out of here with correct alignment, but with a spare cast aluminum wheel and one brake caliper that still was non-functional.
Believe me when I tell you that I understand that everyone is tightening their belts right now-but your wheels, tires and brakes are not the right places to try and save money.
Dave
George, it’s not as simple as “refusing to release the vehicle”. We repair professionals are not allowed to confiscate a vehicle, or hold a customer hostage merely due to our opinion that a vehicle isn’t safe. Sure we may believe that a part may fail in the future, but we can’t replace the wheels that the trailer was built with simply because there are “better” ones available. It’s not the same as if they’d spotted a crack or some other sign of immediate danger.
George
I question the repair shop, If he seen how unsafe the vehicle was he should have refused to release the vehicle to the customer and reported it to the law enforcement in the area.
Robert
Hello John,
Excellent question. Being involved in the aftermarket and repair industry ourselves castings and forgings are very important to me. On aftermarket or original equipment wheels the easiest way is to look at the back side of the wheel. If the unfinished surface looks grainy & rough it is most likely cast. If it is forged it will most likely have a smooth finish. There are 2 main players building forged aluminum wheels for the truck /trailer market that I am aware of. They are “Alcoa Aluminum” & “Firestone Accuride”. We just unstalled a Trail Air Center Point suspension yesterday on a gentleman’s 5th wheel and it had Chinese cast aluminum wheels on it. The main reason is the cost is much less for a cast wheel. It just won’t have the strentgh of a forged wheel.
Best wishes for “Safer & Happier Driving”
Robert A. Henderson
John Sacchetti
Great article but here’s a question for ya…
How do we determine if the wheels on our fiver are cast or forged Al?
Thanks
John
Robert
Thank you all for the great comments. It is hard to put a price on safety. With the fuel price coming down we all want to travel more. Let’s be careful if we are pushing our vehicles and components near their maximum Gross Vehicle limits.
God bless you, Robert
RV Bob
Wow thanks for the information, I been tempted to add a set of these cast aluminum wheels to my motorhome. Looks like forged is the only safe way
Robert Grant
I don’t wish him “lots of luck”. I wish all the rest of us luck that have to share the road with him as well as the left lane hoggers among us that cruise the highways at escessive speeds for these large, heavy, complicated vehicles, most of which are in the hands of rank, untrained and inexperienced drivers.
Louella Giddings
That’s just scary!! I can’t believe he couldn’t see that you only had his best interest in not only the RV but his life and perhaps others. I wish him lots of luck.
Rob
I learned something from your article. Thank you