Unibody vs Body-on-Frame for Overlanding

[Dysan]

I have searched on this topic but haven't found much information. I am curious as to what some of you think of a unibody vs body-on-frame for an overlanding rig. I will be moving back to the mainland from Hawaii sometime in the next year or two, love Hawaii but my wife wants to move back for family. I unfortunately only have a 2010 Sonata, but will be purchasing a vehicle once we get back to the mainland and I am trying to do as much research as possible. I have owned 2 Cherokees(XJs), a 96 Dodge Ram Dually and a 99 Grand Cherokee. I also have the advantage that I have worked for the rental car industry since 2002, so have had exposure to a lot of different vehicles.

I am wanting to know what everyone's opinion is on a unibody vs body-on-frame construction, because I had to get rid of my 99 Grand Cherokee, which I got rid of because there was a lot of rust, a hole developed right above the "frame-rail" behind the drivers front seat, and moving to where things rust out fast.

 

[Theoretician]

This is like asking whether steel or aluminum or carbon fiber is stronger - the question has inadequate specificity. Designing to the strengths matters more than the strengths themselves. XJs were quite popular because they worked, but these days they're aging out of the game. Wranglers are popular because they work. Trucks are popular because they work.

BoF is easier to build up enough to handle rough country, but if you never go into the boulder fields and mud bogs then its pretty arguable if the cost of weight of a BoF is worth it over a unibody.

 

[StuntmanMike]

I think it depends on the rig you are starting with.

My '97 Grand Cherokee (ZJ) was anvil reliable, but I got rid of it because of corrosion. Not so much on the unibody, but everywhere else.

I'm kinda looking for a 3rd gen Toyota 4Runner (BOF), but am realizing finding a nice one in New England is going to be hard, because these also suffer the dreaded Toyota frame rust. I've seen some that look nearly mint on the exterior, but the frames look like they sat in the ocean for a year. The rear lower control arm mounts literally rot right off the frame.

There are some super hardcore XJ's and ZJ/WJ's out there, so I don't think unibody is any type of hindrance as long as it's in good shape. I think the main advantage of BOF is that you have the frame to attach sliders, tow hooks, winch mounts, etc to. All that can be done on a unibody, it might just take more work/engineering and $$.

On that note, I'm actually thinking of skipping the T4R and going with a WJ Grand Cherokee. Solid axles will be better ofroad, and the V8 power will be way better than the little 3.4L in the Toy.

 

[FJ81]

What matters is that it fits the budget and needs for you. Choose a model that has aftermarket offerings for whatever future upgrades you may need, unless you are the DIY kind! I had a 2000 Dodge Ram 2500, QCLB 4x4, Cummins. I miss the old girl, but I am very happy with my FZJ80 now!

 

[Junktj]

Unibody vehicles like xj, zj, and wjs will work off road, but using unibody bracing is a very good idea in the long run.
When used hard the unibody over time will become tweaked, happened to the old xj I had years ago...

 

[Anak]

You can make either one work.

I have an XJ and a Suburban. I prefer the XJ for offroad trips because it is lighter.

On the rust front, my previous Suburban got retired on account of rust. Body rust. Frame was fine, but every time you closed a door you got a shower of rust. OTOH, if I come across a good donor body I can resurrect that rig pretty gracefully. That sort of resurrection won't be possible with the Cherokee, should that day ever come.

 

[Murphy Slaw]

6 of one, half dozen of the other......

 

[Dakota Houligans]

I tend to look at vehicles as tools. I need them to do a task. If you figure out what you need it to do ( as in how many people, how much gear, how long, and where and how you will be driving it). Your options on vehicles while get narrowed down. Then look at reliability and what is available for it. Or what you can build it to be. Every vehicle I own has a purpose just like my tools. If you can't or don't want to build custom parts stick with something that has lots of aftermarket support. Paying a fab shop to build you custom stuff could get expensive.

 

[TerryD]

I owned a Cherokee for about 8 years. It was a great vehicle. It was rust in the "frame" tubes above the rear axle that cast the deciding vote to sell it and move on. When I went looking for a replacement, I decided I wanted body on frame for the added rigidity.

There were several times off-road when I opened the hatch and it would not close back because of the twist in the body. I also felt like attaching things like sliders and bumpers would be much easier and also stronger with a framed vehicle.

I wouldn't turn down another Cherokee, but I do personally feel like the unibody is a bit of a flaw with them. That's my personal opinion though, you just have to consider what direction your taking and how far that way you are going.

 

[Arailt]

Depends on your definition of overlanding. If you're car camping in state/national parks, unibody is fine. If you're going to push the vehicle hard over rough terrain (Moab, Rubicon, etc.), BOF is the better choice. They provide a much stronger platform to mount sliders, skids, bumpers, and winches. Also, as someone already mentioned, you don't have to worry about BOF vehicles twisting out of shape from hard wheeling.

I had a XJ for several years and opening any of the doors off camber meant I couldn't close them, which was a giant PIA on more difficult trails. Very capable otherwise.

 

[Dysan]

Thanks for all the replies. While discussing with the wife about vehicle options, decided I will be looking for a Chevy Sub/GMC Yukon XL. Made that decision based on the wife has a company car that changes weekly(Rental Industry) and she is always restricted to sedans and 5 seater SUVs during Thankgiving and Christmas when we have family over. So since we will need the extra space on the one vehicle we will own, can't really do anything smaller. Not into anything hardcore so the vehicle should suit my needs, plus it has the largest aftermarket support of all the full-size SUVs that I could see in my research. Now to decide which platform to go with. My wife wants me to have the newest one so I can have bluetooth, but looks like I can add bluetooth through the reader for between $100 to $800 depending on the radio.

Now to do even more research to narrow the field down for when I get back to the states and actually start the process of getting said vehicle.

 

[Anak]

Suburbans are a good solid platform and make a great family hauler.

Happy hunting.

 

[TerryD]

Thanks for all the replies. While discussing with the wife about vehicle options, decided I will be looking for a Chevy Sub/GMC Yukon XL. Made that decision based on the wife has a company car that changes weekly(Rental Industry) and she is always restricted to sedans and 5 seater SUVs during Thankgiving and Christmas when we have family over. So since we will need the extra space on the one vehicle we will own, can't really do anything smaller. Not into anything hardcore so the vehicle should suit my needs, plus it has the largest aftermarket support of all the full-size SUVs that I could see in my research. Now to decide which platform to go with. My wife wants me to have the newest one so I can have bluetooth, but looks like I can add bluetooth through the reader for between $100 to $800 depending on the radio.

Now to do even more research to narrow the field down for when I get back to the states and actually start the process of getting said vehicle.

We really loved our Suburban but there's no way we'd be able to get one through most of the trails here on the east coast without plenty of body damage. Best of luck to you! I think you'll love it.