Large Family Sportsmobile

[daveb]

FWIW there’s been a several times where if I didn't have the front locker engaged I wouldn't have made it and it was something a jeep W/O lockers could have done (mainly loose gravel/rock). These vans are heavy! I have limited slip full floater in the rear. I do have a pull-pal and winch as well but it's much easier to push a button.

[TwoVans]

I've been led to believe that with a limited slip, you can essentially "lock" it up by applying the brake a little while on the gas. I've never been in a situation to try this. Can anyone confirm?

Additionally, if you've got an ARB in the front, it's an open diff when not engaged. That, of course, is not helping keep you moving in a low traction senerio. In that case, you are essentially in two wheel drive unti you lock up.

Make no mistake, I've experienced the advantage of a rig with lockers next to one without more times than I can count (lucky for me, I'm the one with the lockers). I'm just making a calculated guess that I'll get bigger bang for the buck elsewhere on the van and that the limited slip will by far out last the many moving parts associated with the ARB.

Hopefully, there will be MANY opportunities to run side by side to find out the definitive answer.

[daveb]

I missed you wanted to put one in the front. Well I'm not that big of a dirt jockey but are you trying to make an AWD van?

[TwoVans]

Not really. I'm trying to focus my efforts on choices that meet the following criteria (in order of precedence):

1. Moves the entire family around safely.
2. Will have maximum chance to outlast the requirement to move the entire family (read long term reliability).
3. Will provide maximum 4x4 capability.

From what I have experienced, although lockers provide a sweet capability, it comes at the expence of reliability. I'm thinking I will retain the majority of the capability with a big jump in reliability. Plus, the vast majority of driving is done unlocked. With ARB, that is open.

OBTW, if you think my thought process is flawed, please feel free to spout off. I have little to no ego, and I haven't committed yet.

[pjpvi]

Back to the "locking up a limited slip", this particular situation below I was going nowhere in 4lo with one unweighted wheel at each end of the van (rear driver side tire slipped into a washout). I was just getting ready to winch when I remembered the applying the brake and gas to lock up the limited slip trick. Did it and it popped right out.

So far I've gotten everywhere I've tried to go with my set-up. A locker would give a nice sense of security though.



Phil

[SMBDAD]

If you lock the front hubs will both tire spin? If you lock the front hubs and one tire is has no wieght on it, it will spin leaving the front useless?

[BroncoHauler]

Originally Posted by pjpvi

Back to the "locking up a limited slip", this particular situation below I was going nowhere in 4lo with one unweighted wheel at each end of the van (rear driver side tire slipped into a washout). I was just getting ready to winch when I remembered the applying the brake and gas to lock up the limited slip trick. Did it and it popped right out.

So far I've gotten everywhere I've tried to go with my set-up. A locker would give a nice sense of security though.



Phil

Applying the brake and gas can help with an open diff as well. In certain circumstances it can provide just enough loading to get the tires moving.

Phil, is it an opitcal illusion from the angle of the camera, or is your front Aluminess uneven. or did your van body flex enough in that spot with respect to the van frame (where the Aluminess is attached to)?


Herb

[TwoVans]

Originally Posted by pjpvi

Back to the "locking up a limited slip", this particular situation below I was going nowhere in 4lo with one unweighted wheel at each end of the van (rear driver side tire slipped into a washout). I was just getting ready to winch when I remembered the applying the brake and gas to lock up the limited slip trick. Did it and it popped right out.

Phil

Phil,

Thanks for confirming what I've been told with real-world experience with an SMB. That adds to my confidence about my plan.

Eric

[pjpvi]

Phil, is it an opitcal illusion from the angle of the camera, or is your front Aluminess uneven. or did your van body flex enough in that spot with respect to the van frame (where the Aluminess is attached to)?

Herb,

Somebody else noticed that a long time ago too. That is a good example of how much the front sway bar really works when it is hooked up. This was not a technical trail, so I didn't disconnect the front sway bar and yes, it did twist the van some while I was in this position. It did untwist though! Had the front sway bar been disconnected, both front tires would have probably had good traction and I most likely would have never even been temporarily stuck.

Here's a picture of more articulation I can get with the front sway bar disconnected and without the van body/frame twisting (note the bumper is in-line with the van).



Looking at these pictures really makes me want to get out of the office and head to the mountains!

Phil

[TwoVans]

Originally Posted by SMBDAD

If you lock the front hubs will both tire spin? If you lock the front hubs and one tire is has no wieght on it, it will spin leaving the front useless?

That is essentially correct with an open diff. "Locking" the front hub is a seperate concept from locking the diff. Locking the hub is what allows power to go to the front axle. Power essentially only goes to one wheel at a time. The locking diff connects the two axle shafts within the axle housing and applies equal power two both wheels on the axle.

The standard Dynatrac axle comes with an open diff so the above applies if not upgraded. If an ARB locker is added, it is still an open diff when the locker is not engaged. This is why you can find yourself stuck in 4 wheel drive, then drive right out with a flick ofthe switch.

A limited slip helps get the power to the wheel with traction. Therefore, the likelyhood of needing both wheels to turn should be dramatically reduced.