ExRocketScientist wrote:
sh410 wrote:
From FE's post:
"GTW is what a trailer is supposed to weigh when delivered to the new owner. The CCC placard will list the maximum amount of cargo that can be added to the GTW. When added together those two cannot be more than the vehicle’s GVWR. At that point the only way to find the pin weight is to weigh it. Once the pin weight is deducted from the GTW the remainder - GAW - is what’s being carried by the axles. That weight cannot be more than the GAWR. OE tires must have a total load capacity equal to or greater than GAWR."
According to Dexter Axle:
"The maximum load carrying capacity is limited to the lowest load rating of any individual component selected. For instance, the load rating of a pair of wheels may be lower than the other axle components. If the is the case, the load rating of the total assembly must be reduced accordingly. As a specific example, if a pair of wheels are rated at 1500# each and are use with other components rated at 4000#, the maximum load capacity will be limited to 3000#. If two tires rated at 1400# each and are used on this assembly, then the maximum load carrying capacity is limited to 2800#"
Dexter applications manual
In example from placard you posted, according to Dexter the axles rating are derated to the total of load rating of the tires.
Can you post a reference that OE tires must have a total load capacity equal to or greater than GAWR?
This is one of those sneaky little details. The GAWR is not what the axle manufacturer says it is -- it is what the trailer manufacturer says it is, as long as it does not exceed what the axle manufacturer says.
So typically, a D52 shows up with a GAWR of 5000 pounds instead of 5200 pounds. This allows the trailer manufacturer to legally put the ST225/75R15 load range D tire on the axle -- i.e. trailer manufacturers are allowed to derate axles to suit their needs.
In an earlier post, someone (most likely FE) found a trailer placarded with GAWR of 7000 pounds and the tires were rated at 3420 each. As I mentioned, and either Roger or Barry confirmed, this would be subject to recall because it violates the federal standard. All the trailer manufacturer would have to do is issue new placards that indicated GAWR of 6840 pounds and they would satisfy the recall. Of course, there might be an owner who would take legal action over it being derated after the sale.
Or they would do what Duro did to some of their LRE ST's. Re-brand them at 3520 and 85 pounds inflation. Question is, did they go through the DOT testing at the higher numbers.
The trailers in the 6750 to 7K GAWR range are the biggest problem and the most expensive to fix with new tires and wheels in some cases. At one point they re-certified the Montana wheels to higher 110 lb inflation, to get around the issue. Disregarding FE single voice of opposition the 6K axle and under are easy to fix with LT tires.
Chris
