Hi first time poster, tried this on 4x4 site and was ignored so hopefully I can get help her

I have a 21 foot Chinook RV built on a 2001 2WD Ford E-350 Super Duty with Limited Slip Diff, and DRW with MorRyde suspension system. Currently running stock 225/17/16. Some specs:
UVW 9100lbs
GVWR 10,700
GCWR 18,500

Possible only towing is kayak on small trailer.

My goal is as follows:
To keep 2WD, but to get more ground clearance and traction for off pavement use. I will not be rock crawling or mudding, use will be restricted to washboard dirt and gravel fire/forest and backroads, unimproved remote campsites. Dirt roads may have dips/water gully's/very slight off canter areas. Also in mid-atlantic we get lots of rain so having traction in slippery stuff very important. Ground clearance is major need to not get hung up.

Majority of driving is on highways so payment comfort a necessity.

To meet my needs above I am looking at:
Installing 235/85/16 AT M+S tires, Duratrac or KO2
Installing 4-5" lift
Maybe a rear locker of some sort
New Fox shocks
Fox Steering Stabilizer

Regarding the lift, I am not doing work myself and I am strongly considering Action Vans Perf Suspension System. My only concern is they use blocks in rear, would it be better to use add-a-leaf or new leaf springs over blocks, or for my mild use are blocks OK? Are there other options.

Do you think the size and tires I am looking at are right for my uses?

Do you think I need a locker at all? If I do get locker, I don't think I want one that is always engaged as I don't want thunking sounds when turning etc on pavement. ARB Air Locker is expensive but electron might be interesting, is it worth it for my uses? Any other idea's? Would a TruTrac be beneficial?

Sorry for all the questions and thank you in advance.

 

A true track is a great option for the rear if you don't want a full auto locker. I am not a big fan of selectable lockers in the rear because the offer you no help on the street.

 

 

A true trac is a big help on the street and off road it isn't a full locker but will be fine for what you do with an RV. A selectable locker is no help on the street because it is either an open diff or fully locked, and neither one of those are much help for street driving.

 

In my mind, there are 4 worthy "lockers". Ox and ARB selectable, detroit locker, and detroit tru-trac limited slip.

the full Detroit only unlocks on sharp turns. You will feel it clunk back in, but it is easy to get used to. Be aware with a rear locker that if you accelerate mid turn, the vehicle will want to follow the nose, not the front wheels. This is VERY prevalent on slick pavement. Just don't gas it going around a tight turn.

the tru-trac is the best LS because of its gear drive. This makes it super reliable.

as for the lift, I don't like or trust blocks over 2" tall. You could use a factory f350 block and a small add a leaf. The factory blocks have a huge protrusion that prevents them from spitting out.

I recently took my stock 99 v6 e250 up Rollins Pass in CO to 11,500 ft, and was surprised at it's capability on the old 4x4 trail. Never had a clearance problem, and the long wheel base smoothes the ride out.

 

I'll second (or third?) what's already been said.

I wouldn't go with a selectable (like an ARB) in your application. Yes, it's an open diff on the street so great manners there. And yes, you can engage it on the street if you need it. But any time you lock it it's LOCKED. Like a spool. That's OK in a lightweight trail rig, but with a motorhome you will frequently get too much traction with the heavily loaded rear wheels and it;ll be very annoying and hard on tires at best, and possibly hard on axles which would be a lot worse.

An automatic locker (like a Detroit) is nowhere near as bad on road as some people make it out to be. But it's not "seemless" either. I'd only recommend going with one if you really value the positive locking performance. And in your application I don't think it's at all necessary.

I think a TrueTrac is a great option for you. Really it's only weak spot performance wise is that it doesn't work well when one tire has NO traction. It sends 3.5x as much torque to the tire that's not slipping as it takes to slip the other tire. If you're rockcrawling and one tire is in the air it takes zero torque to slip it, so the TrueTrac sends 3.5 x 0 = 0 torque to the other tire. So it's not a great choice there. But you won't be lifting tires, and almost any time you've got both tires planted you'll have good enough traction on the one that wants to slip for the other to pull you through just fine.

The one exception might be if you have one tire on ice. But in a rear axle the emergency brake trick is really effective with a TrueTrac. Apply the e.brake a little. The torque it takes to slip the e.brake will be multiplied by 3.5 and sent to the other tire. OK, you need to slip that brake too. But you still have 2.5x helping you.

I think you'll be really happy with a TrueTrac

 

Thanks all it does sound like the TruTrac is the way to go, as I can't image having one wheel in air in this thing, I do see ice as a possibility but very rarely and only patches of it.

Neat idea, thanks.

The lift kit I was looking at does use blocks, trying to find out size, I may look at custom leafs instead, depending on price.

 

How will a lift work with the MorRyde suspension system. Would you lose the use of it? I'm not familiar with it so was wondering. The E-350's ride a bit high and for most trails all you need is a little larger tire but without an axle ratio change it may bog you down on the interstate. Do you drive a lot of miles or sit in the parks most of the time? Maybe a more aggressive tire. What are you running now? My E-350's biggest drawback is the open diff. Hate it but I'm rarely off-road except at scout camp and that is only an issue if rain. Let us know how all your mods go with pics. Before and after please

 

Suspension folks say I can keep MorRyde because it attaches to rear of leaf spring. The E-350 is a Chinook Concouse rv, so It actually is pretty low to ground. Most of my miles are highway and only need lift for clearance looking for out of the way primative or remote campsites. My diff is limited slip which should be OK but TruTrak would give more comfort. Diffently getting more aggressive tire and want 235/85 but they won't fit without higher clearance.

 

are we talking about an actual motorhome or still a van? I took my stock v6 99 e250 with stock tires on some pretty gnarly terrain out in the mountains. Just gotta know your limits. It did much better than the escape did last year. Ought to have seen the looks we were getting in the "free candy and naps" creeper van going up this little jeep pass road. 14 miles up, back, up, back, up, and back once more. Once at speeds most would deem unsafe, in a hail storm at midnight for extraction due to altitude sickness.

EDIT: went back and looked, saw it is a motorhome. That's a bit different lol

 

Yes, it is motorhome. Here are two pics, not great but it is at shop getting brakes:

For this one, look behind rear tire, you can see where gray & black water tank release valve hangs under camper body.

 

Oh yea, a 4 or so inch lift and 33s would help you out a lot.