IRS Swap from 2003 Expedition?

[column_shift]

Hello, this is my first post instead of an intro post but I wanted to populate my intro post with pictures of the truck I already have and don't have that figured out yet. I joined this group to find people specializing in my favorite pickup chassis including to speculate on or consider some wilder or more interesting ideas at times.

I'm aware most offroaders are going the solid axle swap route because they want greater off road durability and toughness - but for this topic I need something that will be 85% of the time on the road. But I was trying to think about cool things I might be able to do.


Does anyone have any knowledge or ideas about how feasible it would be to swap the independant rear suspension setup from a Ford Expedition over to something like a 3/4 ton Suburban? IRS is great for ride and handling and road manners, i'm sure i'll have to ask experts on the ford board obviously for what comes from the donor side, i'm just wondering what problems I might face on the chevy recipient side if anyone has any insight. My assumption is both being ladder frames and such the differences shouldn't be too radical. However since i'm not an expert in fabrication (rather I will be learning about it as I pursue this slow, long project) i'm hoping to pick a few brains here first. Any comments?

 

[RichLo]

interesting topic and welcome!

I have never heard of this swap before on these trucks and I'm kind of curious now too.

 

[michael hurd]

Many many moons ago in the lowered street truck scene, some people were swapping the vette IRS suspension in trucks.

If the truck were relatively new, I could understand such motivation, but it hardly makes sense on a 20 year old truck in the rust belt area.

Solid axles may not be the best answer, but you already have one installed. Changing the bushings out ( they will be toast after this long ) and replacing the leaf springs and shocks will help out the ride and handling tremendously.

 

[LML Duramax 95 Z71]

Many many moons ago in the lowered street truck scene, some people were swapping the vette IRS suspension in trucks.

If the truck were relatively new, I could understand such motivation, but it hardly makes sense on a 20 year old truck in the rust belt area.

Solid axles may not be the best answer, but you already have one installed. Changing the bushings out ( they will be toast after this long ) and replacing the leaf springs and shocks will help out the ride and handling tremendously.

I see what you mean there, but on the other hand, the IRS gives far more ground clearance. On a full on offroad or minimal street use build, dual solid axles make sense. For the OPs uses it would make sense.

Hello, this is my first post instead of an intro post but I wanted to populate my intro post with pictures of the truck I already have and don't have that figured out yet. I joined this group to find people specializing in my favorite pickup chassis including to speculate on or consider some wilder or more interesting ideas at times.

I'm aware most offroaders are going the solid axle swap route because they want greater off road durability and toughness - but for this topic I need something that will be 85% of the time on the road. But I was trying to think about cool things I might be able to do.


Does anyone have any knowledge or ideas about how feasible it would be to swap the independant rear suspension setup from a Ford Expedition over to something like a 3/4 ton Suburban? IRS is great for ride and handling and road manners, i'm sure i'll have to ask experts on the ford board obviously for what comes from the donor side, i'm just wondering what problems I might face on the chevy recipient side if anyone has any insight. My assumption is both being ladder frames and such the differences shouldn't be too radical. However since i'm not an expert in fabrication (rather I will be learning about it as I pursue this slow, long project) i'm hoping to pick a few brains here first. Any comments?

Now, as for my comments on your post sir. I am an experienced fabricator and have a lot of usually useless knowledge about vehicles, but here I can use it to help. To my understanding, with the frames being similar, it would be nothing more than making and welding on some mounts. With decent equipment I would estimate the swap to take 2 or 3 weekends if you wake up early and hit it hard all day. Take your measurements, make some brackets out of either 1/8in or 1/4in plate steel and weld it all up. Its one of those things where there really is nothin' to it but to do it.

 

[column_shift]

Many many moons ago in the lowered street truck scene, some people were swapping the vette IRS suspension in trucks.

If the truck were relatively new, I could understand such motivation, but it hardly makes sense on a 20 year old truck in the rust belt area.

Well I already have a 1991 K1500 with about 20,000 miles on it that spent most of it's life garaged not even seeing rain or snow. (though the first few years that it did still affected it) Though I don't think that will be my project truck, i'm more curious about putting it on a Suburban. I'm not averse to getting a nice truck from anywhere in the US and hauling it back for building it up either.

Basically I really like the ride and handling of independant suspension and it's about the only thing that i'm not a perfect fan of on these trucks. An IRS Suburban (with something strong capable of towing and such, dont think i'd do the vette suspension) to me seems like perfection.

 

[column_shift]

I am an experienced fabricator and have a lot of usually useless knowledge about vehicles, but here I can use it to help. To my understanding, with the frames being similar, it would be nothing more than making and welding on some mounts. With decent equipment I would estimate the swap to take 2 or 3 weekends if you wake up early and hit it hard all day. Take your measurements, make some brackets out of either 1/8in or 1/4in plate steel and weld it all up. Its one of those things where there really is nothin' to it but to do it.

Thanks for the suggestions. My fab skills are not YET up to par - but i'm hoping to learn - and one of the things I was hoping to learn on was an application like this. Both older explorers and suburbans are fairly affordable now, so tinkering around and trying to make it work is not an impossible budget application. My main fear was would it require something like cutting and merging the Suburban frame to the rear part of the Expedition frame, but if it's mostly brackets and mounts i'm hoping that's something I could learn to do.

A slightly newer version/not alot of great online pics I can point to offhand, but for those curious the Expedition IRS looks like this:

http://www.ford-trucks.com/wp-content/uploads/2008/01/expedition_161.jpg

 

[LML Duramax 95 Z71]

Thanks for the suggestions. My fab skills are not YET up to par - but i'm hoping to learn - and one of the things I was hoping to learn on was an application like this. Both older explorers and suburbans are fairly affordable now, so tinkering around and trying to make it work is not an impossible budget application. My main fear was would it require something like cutting and merging the Suburban frame to the rear part of the Expedition frame, but if it's mostly brackets and mounts i'm hoping that's something I could learn to do.

A slightly newer version/not alot of great online pics I can point to offhand, but for those curious the Expedition IRS looks like this:

http://www.ford-trucks.com/wp-content/uploads/2008/01/expedition_161.jpg

No problem man, happy to help. I checked that picture and it definitely confirms my theory on just making brackets and mounts. No way will you need to cut and splice the frames if you don't want to. But, on the other hand, if, and this is a big if, the frames are the same sizes (channel height, and overall width from frame-rail to frame-rail) it may be an option to do the cut and splice the frames. There are ways to strengthen the section where the two frames meet so there's no weak-point. Although at the same time, if you do that, you will probably have to make body mount brackets or drill new body mount holes in the top of the frame-rails. Honestly, it's 6 one, half a dozen the other. Just depends on which one YOU are more comfortable doing. If you're not comfortable while taking on this kind of project, stupid little mistakes will be made that just irritate you and slow things down.