The transfer case sticks out sideways towards the driver side where the front driveshaft comes out to the front axle. The front nose of the tanks gets in the way so you have to cut it and weld a plate loosing 3 or gallons or you get an aftermarket tank ($$$$) that is shorter but chubbier and has larger capacity.
Another issue is the driver side catalytic converter. that is on the way of the aforementioned driveshaft so you have to cut the exhaust and re-route it to the passenger side. And list goes on with a lot of little details to take care of....

i documented my build here: Rig Runner build. I did it in the most frugal way but not skipping on safety. Gas tank on page 5.

 

Ah, I get it. I had to go down and take a second look at my tank. Ha!

Awesome blog. I'll be sure to use that as a resource.

 

This is from a good friend who went with a rear locker. He is a fabricator, engineer, and all-around DIY guy.

" I had originally collected nearly all of the parts to do a 4x4 conversion and was only waiting on a good deal on a transfer case. My brother-in-law who runs a 4x4 outfitter recomended I try a rear electric locker instead, before starting a conversion. He thought I might get all of what I was looking for in traction using a locker with RWD without the compromises that happen with the 4x4 conversion. Boy was he spot on.

A solidly locked (by push of a button) rear axle will take you just about anywhere that you would want to go. Muddy trails, backing up grassy slopes, gravel, sand and on. once locked-in, it just goes. I have not been stuck!

The issue with full 4x4 conversions on these vans is that in order for the front axle to clear the oil pan on the engine, you must lift the vehicle. Once you lift it, the center-of-gravity naturally goes up. Also due to the way steering is arranged, bump-steer happens. So imagine going down the highway, way up in the air at 70 mph and you pass over a series of those whoop-di-doos (long rolling bumps in series). The steering on most of the conversions including Quigley and Sportsmobile, causes the whole vehicle to want to swerve left to right! Scary right? A steering dampener helps but doesn't entirely solve the problem."





This van has 80% of the traction of 4x4 (remember electric locker is fully locked solid when engaged) without the weird steering or stability issues. I am so glad we went this route instead of the 4x4 conversion!

BTW, he's selling the van on CL San Francisco. This is not a plug or advertisement for his van. He's detailed what he did to the van and it's useful to all of us who build our vans for adventure.

 

With 40,000 miles on my van since the 4x4 conversion, I can positively say its not scary whatsoever and people that have ridden in my van as passengers have commented how smooth it rides.

Yes, most people could get away with a rear locker and winch and be happy.

Then some of us have been to places where front and rear lockers were required.

 

Properly done, a 4x4 van should ride as good as any big vehicle with similar architecture. Proper alignment and geometry check are necessary. Steering stabilizers are, in general, a patch; I tried them on mine and hated them , it rides better without them. The ride is not like a Cadillac, but I can cruise at 90 mph if I wanted to all day long .

Decent tires and Limited Slip Differential served me well for 10 years on my old 2000 E150 on fire roads, ski trips and long road trips. My current 4x4 E350 has allowed me to do more. In some cases, things I didn't or event shouldn't do, but I wanted to.

Original 2WD front suspension may behave better on the road and higher center of gravity will affect the handling. 4x4 is not an option for everybody: It is expen$$$$ive, requires more maintenance, ... but nobody needs a 400hp sports car to commute to work either.

Love the picture at Hancock pass Mike. My next step is a front locker.

You will not do this with 2WD and a locker, but then again, you may not need to. I wanted to.

 

Hey, could you try and put me in contact with the guy in San Francisco? I live in the Bay Area and I'd love to pick his brain more about this. I suppose I could start with locking out the rear differential and decide if I want to do a full 4x4 conversion later on. Anyone see any issues with that?

That said, and at some point, I would like to go places beyond the capacity of RWD and diff lockers. In the more immediate future, I'd like to have a safer ride during Tahoe snow conditions.

 

A rear locker will help a lot, but to say it's 80% of the traction of a 4WD is overly simplistic and for most uses overly optimistic.

In snow or mud 4WD would be a LOT better than a rear locker, because in those situations a rear locker frequently isn't much better than an open diff. Open diffs always push both tires with the same torque so if one tire slips with low torque it won't push the other tire any harder. Meanwhile a locker will push both tires as hard as they can take, which sounds a lot better. But usually in snow or mud neither tire gets great traction, so the locker is only gaining you the marginally more torque the non-spinning tire will support. Plus you now have both tires spinning so you can't keep it straight. 4WD will push all 4 tires about the same as the locker will push 2 tires. So 4WD, even with 2 open diffs, will give close to twice as much traction as a rear locker and 2WD

On the other hand, on a rough, rocky trail a locker with 2WD might even be better than 4WD with open diffs. On trails like this friction isn't usually the problem (like it is in snow or mud). It's weight distribution. When you get crossed up you have very little (maybe even no) weight on one tire on each axle. With 4WD and open diffs each diff sends the same torque to the planted tires as it takes to spin the unweighted tires. This can be very little, so you end up spinning the tires in the air while sending very little torque to the two on the ground. On the other hand, 2WD and a locker will send all the torque to the one planted rear tire that it can handle. This may well be more than the two open diffs send to the 2 planted tires of the 4WD.

And of course 4WD with 1 or 2 lockers will be better yet.

Still, if someone wants to try a rear locker to see if it's good enough for them, a "lunchbox locker" is pretty cheap and easy to install (no touchy gear setup required!). It won't have as good on-road manners as an open diff (or an unlocked selectable locker like whatever electric locker was being touted). But it will be as effective as the locked selectable when needed.

 

If youre going to start with a rear locker only, just make sure your current rear axle is one youll want to keep.

Mine was a semi float Dana 60 and during my 4x4 conversion I decided to replace it with a 2006 Sterling 10.5 (full float). I didnt want to spend the money on the factory rear end.

 

I've experienced the differences between open, limited slip, and lockers in a few vehicles and in some situations a 2WD locked or with a good limited slip can beat open 4WD. Open 4WD will win in some situations, and if you know how to power brake effectively a factory limited slip or even open carrier can get you through most situations that you'd want to activate a locker for.

 

I have a 02 quigley with a dana 60 full float LS in the back. It gaoes through just about anything in 2wd. However,I have been in soft sand that needed the front axle to be engaged to get out.Both rear wheels dug in.As for front LS/lockers,. I have not had any experience with them as I dont "rock crawl",but I have been told that on ice or some types of snow,they will push the front end straight and not allow the van to sreer straight.If I were to go with a front locker,it would definitly be an electric type. Also,as an aside. I have found that front and rear axles use different gear ratios. 3:55 in back/3:54 in front or 4:11 in back/4:10 in front,. It allows the front to "pull" just enogh to keep the vehicle straight and not want to go sideways 0n slippery road. That is why they tell you not to use 4wd on dry paved roads. just m2c.As far as bump steer; yes there is a little but it has never been a problem once you get used to it. It only occurs when hitting a small bump at hiway speeds and you dont have to compensate for it.Going over up and down hills, it doesnt exist.The reason conversions raise the chassis is to get clearance for the front axle to frame clearance.. I believe mine is 4in and is not a bother to get in and out of the van,although it is a bit difficult for passengers,especially women and children.

 

Mostly the difference is because you can't get exactly the same ratios for a Ford 9" and a Dana 44 (or whatever the axle combo happens to be in the vehicle with slightly mis-matched ratios). I've driven a bunch of different 4WDs on snowy highways, mostly with matching ratios but some with the mis-matches you mention, and none of them have any real tendency to go sideways (but all can be pushed beyond their limits).

Actually your tire diameters will always be slightly off from each other, so really even when going in a straight line with perfectly matched axle ratios you'll get some tire scrub.

But the real reason for not using 4WD on dry pavement is that when you go around corners the front tires have to travel farther than your rear tires, so you'll get bind which will suddenly release and keep repeating until you straighten out. This "crowhopping" can be pretty hard on drivetrain components.

 

Hi Mike - do you have a build thread somewhere? Your van looks great!

 

The difference in ratios is because of the limitations in some combinations of axles. Some vehicles have the same ratio F&R, all of mine have. AFAIK nobody uses different ratios by choice, but being only .01 difference is no issue so they do it when it's more convenient/cheaper than finding an axle pair that can run the same ratio. The reason to not use 4WD on good traction is because when you make a turn the speeds of the front and rear wheels will be different and that forces tires to slip while also putting a lot of stress on the drivetrain.