Independent suspension

[Southern Gorilla]

I can't even imagine the price tag on his custom work. It'd be cheaper to take a year of welding classes at the local tech school, buy a welder, and build my own.

But like I said, this isn't in my plans. I don't think any independent system could handle 40"+ tires. I know SEMA trucks and magazine trucks do it all the time. But I plan to drive my rig further than on and off a trailer.

Well... unless I could find an Oshkosh fire truck to use as a donor.

[El_Diablo]

There are actually ifs rock racers now that seem to do awesome.

As far as the suspension. I'm actually using one of his ideas in my own custom setup for the stang. Its a 5 link that's really a 4 link and 3 link in one. You just alternate between 2 top bars or 1. This combined with a watts link should be one of the most versitile setups out there when its finished.

[Southern Gorilla]

Funny thing is that when the OEMs started switching to IFS it was the crawler guys screaming the loudest about how IFS was useless on trails. Now that a few rigs have started tearing up the trails the crawler guys think IFS is the greatest thing since sliced bread. I've seen the IFS/IRS buggies. Some of them are pretty nicely done. But I don't think the stresses they deal with crawling across rocks at a snail's pace translate into anything useful for screaming down the highway.

But if anybody has pictures of a 4,000# rig on 40"+ tires running IFS/IRS reliably on the road and off I'd definitely be interested in seeing them.

Or a pro-touring IFS/IRS SUV. That would be sweet too. I still know where there's a Wagoneer looking for a good home.

[El_Diablo]

But I don't think the stresses they deal with crawling across rocks at a snail's pace translate into anything useful for screaming down the highway.

But if anybody has pictures of a 4,000# rig on 40"+ tires running IFS/IRS reliably on the road and off I'd definitely be interested in seeing them.

Ever seen shannon cambells ifs rock racer? He's not exactly just crawling at a snails pace. How about some of the lifted h1 hummers that roll on 42's? They're far heavier than 4k lbs and they have ifs and irs. The MRAP (Mine Resistant Armored Personnel) also has 4 wheel independant suspension and weighs well over 4k lbs.

Its really on how tough you build it. Heck, think of how much force a wheel takes when it hits a pot hole at 70mph. I've seen vehicles blow tires and bend wheels and the ifs is still intact. That's a lot of force... I've also seen plenty of crown vics jump curbs at speed and so on and the front suspension holds up just fine.

Just sayin....


Oh, and as far as the pro touring wagoneer. I would love to do it but Ineed to finish my protour/road race mustang first.

[Ghinmi]

Plenty of multipurpose rigs running independent suspension at KOH too.

[Carnuck]

It's not too terribly hard to narrow up the H1 stuff if you have knowhow

[Southern Gorilla]

The MRAP would be my daily driver if I ever woke up wealthy.

I never said independent suspension couldn't work on an FSJ. I only asked if it had been done. I know if I had a ton of money laying around I could easily buy a set of H1 portal hubs and a couple Corvette/Viper D44 diffs and have a pretty beefy drivetrain.

But those parts aren't in my local junkyards. I've seen what the H! hubs sell for. A set of those is out of my budget. So even if the H1 stuff was durable with 42s on a heavy rig I'd never be able to build that. Which is why I'm stuck with solid axles.

But the H1 stuff also wouldn't really work on a street truck. And that's why I started this thread in this section. I was really curious if there was a luxo-touring FSJ roaming around. It seems that would be a lot less complicated to build since the parts are more readily available. And the parts are strong enough since there are a ton of Expeditions rolling around on 31s.

[Husker77]

I guess I thought we were talking about a street truck, more of a lowered racer than something on 40's. Something like ghimi's(sp?), the newer truck irs would all probably be to wide to run any sort of backspacing on your rims.

I've been looking for years for a complete h1 frame to swap a body onto. I'm sure if I ever did find one it would be out of my price range, but there is always hope.

[Southern Gorilla]

I guess I thought we were talking about a street truck, more of a lowered racer than something on 40's. Something like ghimi's(sp?), the newer truck irs would all probably be to wide to run any sort of backspacing on your rims.

That was the original idea behind the thread. But folks assumed I was thinking about plans for my own build. I tried to clear the air by pointing out that my build was incompatible with the idea. And that's when 40s got thrown into the mix.

[ProTouring442]

But if anybody has pictures of a 4,000# rig on 40"+ tires running IFS/IRS reliably on the road and off I'd definitely be interested in seeing them.

This is why I think it might be good to start with the front suspension of a truck. There are a lot of parts out there to lift and strengthen such systems, and these could be put to good use in adapting the front suspension to be used as an IRS. The differential would need to be changed, but adapting the differential of your choice shouldn't be that difficult, and there are myriad axle companies that could make heavier CV shafts for it.

A Ford F150 4X4 weighs in at nearly 5,000 lbs, and the Raptor seems pretty off road capable so I would think such a front suspension system would make a great basis for the rear suspension.

[El_Diablo]

If it were me. I would get a HP 60 front and cut the axle tubes completely off. Then machine some mounting flanges for half shafts and just run a run of the mill HD truck outer knuckle and just use a setup like you would find on a UTV only built to a larger scale. For the rear I would do pretty much the same thing with a 9 inch or 14 bolt except instead of a steering rack and pinion you would just have fixed tie rods for the rear... or you could always set up rear steer.

[Husker77]

If I was going to do something like that I would use a modified ford ttb setup. Autofab makes a kit that has like 20" of travel or something, dana 44 center or the f250 has the dana 50. I know people dog on the ttb but it is strong and is used a lot in desert racing.

[Southern Gorilla]

If I didn't know better I'd say some of you have been thinking about this for a while already.

I think I'll just sit back and watch the ideas fly.

Ok, I'll throw something into the mix... would it be possible to use an ordinary pinion mounting flange and seal as the output on the side of the diff? Or is a pinion seal somehow different from an axle seal?

[Southern Gorilla]

I did a bit more research. It really looks like the Expedition is the perfect donor for a street FSJ IRS swap. The ring gear is the same 9.75" as a D60. I can't find out for sure if it is a D60 or not. So I don't know if it has the same diameter shafts or what U-joint yoke it has. But it should be plenty strong for any street machine. Strong enough for most 'wheelers too. I'm not sure that's enough meat for 40"+ tires though.

[Carnuck]

I can't recall if the Excursion was stronger or not.