Differentials, adding a full-floater

[djm68]

Hello,

My wife and I just had our first adventure in our 2009 Quadvan: we drove back from Fresno CA after having an SMB top installed on our van. While exploring some remote, back roads we managed to get stuck in a moderately deep, icy snow patch. We might have been able to plow threw the snow well enough, but the rear end of the van fishtailed quite a bit, putting the tail end uncomfortably close to the roads edge and a very steep ravine. We managed to dig ourselves out and get on the road, but I was underwhelmed with the trucks traction.

I know I wanted to add some sorta of locker or limited slip diff from and rear. The rear end is, unfortunately, only a semi-floater; I would like to upgrade to a FF. So, a few questions:

What vehicles should I look for to get a donor rear axle? Excursion and f350s? Year range? I should be looking for a Sterling 10.5, correct?

Regarding differentials: I come from a sports car back ground, so I am mostly familiar with limited slips or Quaife style torque biasing differentials. I would think the needs of a 4x4 camper van are fairly different: I want to be able to get through snow, mud and sand, and reliability is paramount. Initially we will be doing short trips: 1-2 weeks of camping, but we do plan a 1+ year trip in the near-ish future.

Thanks,
DJM

2009 Ford E350 SuperDuty 6.0PSD, Quadvan 4x4, SMB pop-top

 

[ujoint]

You have a few options. If you don't have large tires (over 35's) or plan on towing a lot, the semi float will be fine. The only locker available is from ARB, which is a good unit. Up front, I'd recommend a good limited slip like a Detroit True Trac. These will give you plenty of traction!!

Is the van 8 on 6.5 or 8 on 170mm?

 

[djm68]

You have a few options. If you don't have large tires (over 35's) or plan on towing a lot, the semi float will be fine. The only locker available is from ARB, which is a good unit. Up front, I'd recommend a good limited slip like a Detroit True Trac. These will give you plenty of traction!!

Is the van 8 on 6.5 or 8 on 170mm?

Thanks for the input. I do not plan on towing much, but the van will grow in girth as we finish the interior, add on board water, heat, a small motor cycle is likely to be on the back as well. I was under the impression these heavy vans really benefit from the FF.

I am curious why you do not suggest a front locker? Would the Detroit True Trac provide better turning vs a locker? I was thinking a locker, up front, is ideal as it is only locked when you need it.

WRT to the bolt pattern: 8 on 170mm.

Thanks for your input.

DJM

 

[charlieaarons]

You have a few options. If you don't have large tires (over 35's) or plan on towing a lot, the semi float will be fine. The only locker available is from ARB, which is a good unit. Up front, I'd recommend a good limited slip like a Detroit True Trac. These will give you plenty of traction!!

Is the van 8 on 6.5 or 8 on 170mm?

Not true, the most reliable locker is a Detroit Locker, which requires some brain input to use properly. For example, on slippery roads engage 4WD early.

Charlie

 

[notmiller]

Not true, the most reliable locker is a Detroit Locker, which requires some brain input to use properly. For example, on slippery roads engage 4WD early.

Charlie

Chris and Charlie are both correct, and you'll always hear differing opinions. I run a Detroit Locker in the rear of my daily driver/ rock crawler. Essentially, it provides full power to both wheels normally, but disengages when it "senses" that one tire needs to spin faster, like in a turning situation. The Detroit is probably the best and quietest locker, but after running it now for 6 or 7 years it likes to unwind with a big ka-chunk at least once a week, freaking out the people around me, but not actually doing any harm. Lockers can sometimes be more difficult to handle on icy roads, especially when turning, because they may change their mind at the wrong time. As Charlie stated, they require some brain power, so you must be conscious of that fact. For that reason, I chose to put an ARB in the rear of our van so that I could have a reliable, controllable diff depending on the situation. The last thing I want is a locker on a 9,000lb van to unwind on an icy road around a turn. For fronts, I've always run a limited slip/posi and agree with Chris' choice there, too. They get the job done well for a good price.

 

[Toolman]

I have front and rear ARB lockers and love em. However I don't think I needed the front ARB. It's nice to have when I need it but it makes turning really tough. Also you don't always want a locker on ice, snow or sand. I use them as emergency use. I would never use the rear locker on an icy hilly road. When the rear is locked it has a tendency to push you straight forward when you really want it to turn. The ice provides little traction for the front tires to grab and pull the van around. Having complete control of my axles is very important to me. I hate Detroit lockers because they make that horrific noise.
BTW the semi float has been working very well for me.

 

[CodyY]

Hard to go wrong with a front True-Trac in an "all-around" vehicle

 

[ujoint]

Thanks for the input. I do not plan on towing much, but the van will grow in girth as we finish the interior, add on board water, heat, a small motor cycle is likely to be on the back as well. I was under the impression these heavy vans really benefit from the FF.

I am curious why you do not suggest a front locker? Would the Detroit True Trac provide better turning vs a locker? I was thinking a locker, up front, is ideal as it is only locked when you need it.

DJM

I don't like a full locker up front for a few reasons. They're not really needed on a rig this big, they cause you to fight the steering, and they're hard on the front end components. A good aggressive limited slip is just more versatile for all conditions. My van has a powerlock front diff & I wouldn't change a thing! It just gives you more control in my opinion.

Not true, the most reliable locker is a Detroit Locker, which requires some brain input to use properly. For example, on slippery roads engage 4WD early.

Charlie

Not sure what you mean. I have a Detroit in the back of my van, and I never said the ARB was the most reliable, it's just the only option for this application.

 

[djm68]

Thanks for all the info, guys. I have decided that I will go with an Eaton type gear based diff or a true LSD in the front. I am tempted to go with the gear based diff as they require little/no additional maintenance vs. a LSD. Any thoughts on this?

WRT to the rear end: if I stick with the sterling, then the ARB seems the obvious choice. Is it possible (advisable?) to run a dana 60 in the rear?

Cheers,
DJM

 

[ujoint]

Since you're already 8 on 170mm, the Sterling is the best option. A full float van 60 will need adapters to change the pattern and you're locker options are slim to none without custom shafts/etc. I have a new Sterling install kit, will be posting a pic & price on my build thread today!

 

[Jakey]

If I'm familiar with what Quadvan uses, it more than likely is 2005+ style F250/F350 Axle up front.
You will want a 2005+ F250/F350 Rear Axle to match the width of your front axle.
The 1999-2004 F250/F350 10.5 are narrower due to the near center[+.250"] wheel offset unlike the 2005+ wheels with even more positive offset.

 

[ujoint]

The 99-04 Sterlings are 68.5" WMS to WMS, 05 up is 70.5.

 

[djm68]

If I'm familiar with what Quadvan uses, it more than likely is 2005+ style F250/F350 Axle up front.
You will want a 2005+ F250/F350 Rear Axle to match the width of your front axle.
The 1999-2004 F250/F350 10.5 are narrower due to the near center[+.250"] wheel offset unlike the 2005+ wheels with even more positive offset.

Yes, Quadvan uses the later style f250/f350 gear up front.

Thanks for the info...now I know what years to look for.

Cheers,
DJM

 

[djm68]

The 99-04 Sterlings are 68.5" WMS to WMS, 05 up is 70.5.

Thanks for the info, Chris. One more question: will I need your Sterling adapter kit to mount a 10.5" axle on my '09 e350, or is this a bolt in operation?

Cheers,
DJM

 

[ujoint]

Not a bolt in deal, and my kit will make it simpler/easier