People are still very stuck in the old "solid rear axle required" mindset

[shane_th_ee]

But it doesn't change the fact that anyone with the $60-100k investment into customizations is going to be smart enough to look for the right platform to build upon. They won't pick a behemoth like an Expedition (or a Tahoe/ Suburban) to start with.

Or, they might pick a behemoth to start with, but it'll be a Land Cruiser. There's almost as many aftermarket parts available for those as for Wranglers.

 

[Mike Wolfe]

The Military HUMMER is equipped with a very well designed IRS as I recall

 

[Artie]

I don’t plan on rock crawling or getting crazy with any off road driving but I, as many, do need a good mix of cargo/people/towing capacity with 4x4. You do end up with having to make compromises and I’m ok with giving up a solid rear axle, based on my needs. I would like a better approach angle but I guess I got ventilated massaging seats instead.

 

[duneslider]

The Military HUMMER is equipped with a very well designed IRS as I recall

I guess that depends on what you classify as well designed. Almost zero articulation, rides rough, great ground clearance, tows well. Again, it did well for what it was designed to do but "rock crawling" and comfort were not design criteria.

 

[rjdelp7]

I read the Expedition rear axle change, was for more cargo space and to lower the body. This issue was also debated in the Mustang forum. Ford switched them over recently. I believe it was because every 'car magazine' , would mention the solid axle, as a weakness in handling. In reality and owning one with the solid axle, it handles just fine. Most actual Mustang owners(not car testers), never complain about it.

 

[3DogRanch]

Is anyone old enough to remember all the old Explorer roll-overs from defective tires? It seems to me (may be coincidental) that Ford went to IRS after the NTSB report came out about how the Explorer was unstable in the event of a rear tire failure. Lowering the body as rjdelp7 suggests could have been a part of that calculation, or as others have suggested, the auto-industry-media seems to go overboard explaining that the "live axle" was invented for buckboards and horse-drawn carriages and any modern vehicle that uses a live axle is lazy design.

Anyway, I will not setup my Expedition for rock crawling or extreme off-road, but I do expect it to serve as a daily driver and family vacation hauler. When I lived closer to a city center and hurricane threat, it was also to serve as a "bug-out" vehicle for 3 humans and 3 dogs. The Yukon Denali was a close second choice for me, but I would have to buy CPO/Used to get it into a comfortable price range. Having kept my last truck for 12 years, I can justify the depreciation of buying new.

 

[JExpedition07]

The axle generally is better for hauling/towing. Look at our Gross Rear Axle Weight Rating vs any F-150, the IRS cannot handle as much weight as a semi-floating axle. Then go a step higher to a fully floating axle like in the Super Duty F-250 and it’s an eye opener how much weight it can handle vs IRS.

 

[JExpedition07]

For example a few years ago GM switched to IFS (Ind. Front Suspension) on the 2500 HD, Ford said no way and instead redesigned an even stronger solid front axle in 2011 for the F-250, Look at the front axle rating on the GM IFS vs the Super Duty Dana Axle, it becomes clear which one you’d rather put a plow on fast. The axle also has much less point of weakness with that stress.

Yes I like my IRS on the Expedition with the smooth ride and it does well for me, but I’m realistic it’s not the end all.

 

[shane_th_ee]

And yet the 3.73 IRS has a higher RAWR than any of the solid rear axles in the GM BOF SUVs

 

[JExpedition07]

And yet the 3.73 IRS has a higher RAWR than any of the solid rear axles in the GM BOF SUVs

What’s the rear GAWR on a 4th gen? My 3rd gen is 4,250 pounds where comparable year F-150 is 4,800 pounds.