Originally Posted By: hattaresguy
I will disagree with you here, their is a reason no real truck uses IRS or even IFS.
You're a bit mistaken. The HMMWV has used IFS and IRS since the get-go, from 1984. The empty weight of a HMMWV is nearly 6,000 pounds, with a rated payload of 2,500-4,400 pounds.
The HMMWV's replacement, the MRAP, also uses IFS and IRS. A third party upgrade available for these, from AxleTech, is rated at 25,000 pounds per axle. Heavy duty indeed.
The M1117 also uses independent suspension, front and rear. Its dry weight is nearly 30,000 pounds.
Clearly, heavy duty vehicles do use independent suspension, and independent suspension has demonstrated its durability over decades in heavy duty use.
Originally Posted By: hattaresguy
It simply cannot handle the weight of heavy loads, and no its not safe to have a ton of chamber like that on tires, when your carrying a lot. That's how you ruin your wheel bearings and could break an axle too.
The alignment characteristic is 'camber', and it's very safe. In fact, it provides more vehicle stability and improved vehicle handling than having zero camber, as with a live solid axle. Wheel bearings are desinged for this, and no, you cannot "break an axle". You realize, of course, that there is no actual load on the axles themselves. The axles (CV shafts) ride in bearings on both sides and are "full floating" to steal a term from the solid axle glossary. No matter how much weight you do or don't load into the back of an IRS vehicle, the suspension "load" on the axles is the same, because they bear no weight.
It looks, visually, as if the "axles" are bending under the weight of the load. But that's not happening at all. The suspension geometry is producing exactly what the engineers desired: negative camber gain with wheel travel. As stated earlier, this improves vehicle stability and handling, which becomes increasingly important as the load increases.
