Journey with Confidence RV GPS App RV Trip Planner RV LIFE Campground Reviews RV Maintenance Take a Speed Test Free 7 Day Trial ×
 


Reply
 
Thread Tools Display Modes
 
Old 05-06-2007, 11:45 AM   #11
Senior Member
 
jage's Avatar
 
Join Date: Apr 2007
Location: Parker, CO
Posts: 7,643
Re: 4wd, limited slip, lockers

Quote:
Originally Posted by geoffff
The ARB air locker uses its own compressor, not the onboard ExtremeAire compressor. So, I have two air compressors on my van.

-- Geoff
I don't think that's a requirement though, the ARB should be able to use any pressurized air source.

__________________
it was good to be back
jage is offline   Reply With Quote
Old 05-06-2007, 12:15 PM   #12
Senior Member
 
geoffff's Avatar
 
Join Date: Apr 2007
Location: Seattle, WA
Posts: 1,061
two compressors

Quote:
I don't think that's a requirement though, the ARB should be able to use any pressurized air source.
For some reason (that I forget), Sportsmobile insisted that I install both compressors.

-- Geoff
__________________
2004 Ford, SMB 4x4, RB-50
https://octopup.org/sportsmobile
geoffff is offline   Reply With Quote
Old 05-07-2007, 04:14 PM   #13
Senior Member
 
Buji's Avatar
 
Join Date: Apr 2007
Location: Mather, CA
Posts: 378
You're right Geoff, they do. I believe it's because the extreme air compressor puts out much more PSI than the arb pneumatics are supposed to need, but a regulator could take care of that.

The other option would be to use manually locking hubs, which are good for the occaisonal issue, but sometimes you don't want to get out and in the mud manually lock your hubs. Depends on your usage.

My plan is to add the hubs later with a regulator to the onboard compressor
__________________
-Buji
_________________________
Modified EB-22 with Penthouse Top
https://www.sportsmobileforum.com/alb...43791a54be.jpg
Buji is offline   Reply With Quote
Old 05-07-2007, 05:44 PM   #14
Senior Member
 
Jeffrey's Avatar
 
Join Date: Apr 2007
Location: Santa Barbara, CA
Posts: 1,841
Garage
Buji,

Unless I misunderstood, you are referring to lockers, but talking about manual locking front hubs. Two different things.

I am strongly considering lockers in my soon to be van. I'm not going to have the onboard ExtremeAire compressor because I carry a Power Tank (compressed CO2). However, I also carry a small 12v portable compressor that fills a tire in about 20 minutes, for emergencies. The tank fills a tire in less than 20 seconds, and also runs the air ratchet. I may end up with the ARB pump for the lockers, too!
__________________
'07 RB-50 - My Photo Site -- K1JGS --
Jeffrey is offline   Reply With Quote
Old 05-11-2007, 01:00 PM   #15
Senior Member
 
Join Date: Apr 2007
Location: Reno, NV
Posts: 282
Quote:
Originally Posted by jage


Limited slip doesn't really engage or disengage, but there's a technique using your brakes to make it work better (I've actually gotten out of a twisted no traction situation with my Jeep Wrangler using only limited slip and the brake to prove it would work).
Hey, can you explain more about this? Is this what the miltary refers to as "brake-throttle modulation"?

I was totally blown away by what we could do in a HMMWV: driving up out of right angle stream bed with a height of at least 3'... we'd literally be balancing on the RF and LR wheel with the other two wheels totally, way off the ground, and could move forward and backwards just fine. To do it, you'd start with the brake engaged while in drive. Then give it some gas, then slowly let off the brake until you were moving, and drive with both the accelerator and the brake pedels depressed. Worked like a charm. The guy who was showing me how to do it said something about there being a danger in quickly releasing the brake during this operation, as it could do some sort of damage, but all that explanation was lost on me; I'm not much of a gear head.

So, is this the same thing, or is there something in the HMMWV that's different?
__________________
2006 RB50 6.0 Diesel
Flatplate water heater (mounted INSIDE), portable butane stove (no propane)
SMB 4WD
Amsoil
kzemach is offline   Reply With Quote
Old 05-11-2007, 01:48 PM   #16
Senior Member
 
geoffff's Avatar
 
Join Date: Apr 2007
Location: Seattle, WA
Posts: 1,061
driving with the brake

When you have one wheel in the air (with an open differential), by applying a little brake and gas at the same time, you're increasing the amount of torque that can be applied to that wheel in the air. With the brake applied, it takes more torque to turn a wheel in the air. (It otherwise takes essentially zero torque to spin that wheel.)

Because an open differential always sends equal torque to both wheels, when you apply the brake with the gas, the wheel on the ground now also gets some torque, too -- the amount depends on just how much you press the brake.

-- Geoff
__________________
2004 Ford, SMB 4x4, RB-50
https://octopup.org/sportsmobile
geoffff is offline   Reply With Quote
Old 05-11-2007, 03:45 PM   #17
Senior Member
 
Jeffrey's Avatar
 
Join Date: Apr 2007
Location: Santa Barbara, CA
Posts: 1,841
Garage
Having just returned from the SMB factory, I discussed this issue with them and got the opinion that in most cases, with the SMB 4x4, the ARB front locker working with the stock limited slip rear is sufficient. Most of the rigs they sell are equipped like that, and most of the off-road-ready finished vans I saw were the same. So I went with that configuration myself.
__________________
'07 RB-50 - My Photo Site -- K1JGS --
Jeffrey is offline   Reply With Quote
Old 05-14-2007, 10:28 AM   #18
Senior Member
 
Buji's Avatar
 
Join Date: Apr 2007
Location: Mather, CA
Posts: 378
Quote:
Originally Posted by Jeffrey
Buji,

Unless I misunderstood, you are referring to lockers, but talking about manual locking front hubs. Two different things.
No you're right, I was spacing. I don't think anyone wants to crawl under a vehicle to engadge a manual differential!

Eaton is also manufacturing electronic locking differentials, but I'm not sure if they have an fitment for the this type of application.
__________________
-Buji
_________________________
Modified EB-22 with Penthouse Top
https://www.sportsmobileforum.com/alb...43791a54be.jpg
Buji is offline   Reply With Quote
Old 05-14-2007, 11:00 AM   #19
Senior Member
 
jage's Avatar
 
Join Date: Apr 2007
Location: Parker, CO
Posts: 7,643
There are electric lockers available for the Dana44 and Dana 60, and there are also OX lockers, which are cable activated. Both are alternatives to ARB if you don't want to run air but still want selectable.

There is also the option of putting in a regular full-time locker, and the Jeep guys swear that you can't tell there is a Detroit in a front axle when you're in 2wd, but I'm still leery of doing this.

Also with a locker engaged in an axle, when the tires break traction, there is nothing preventing sideways motion and the axle whichever direction it wants. Whereas with an open diff, limited slip (usually), or an deselected locker, the wheel not under complete power will provide tracking, so while you may not go forward or back, you also won't be as likely to just go sideways.

Having had experience I'd rather drive on snow and ice open than with lockers.
__________________
it was good to be back
jage is offline   Reply With Quote
Old 05-20-2007, 08:10 PM   #20
Member
 
Join Date: Apr 2007
Location: Gunnison CO
Posts: 34
Lockers vs limited slip

We got a limited slip on the rear and ARB locker on the front of our van. I once had a Bronco with limited slips on both ends, and the front end had a nasty tendency to refuse to turn on slippery surfaces. Being able to totally unlock the front diff allows equal torque distribution to each wheel for most situations, while having the option of locking them together if you're really stuck.

The locker saved me an expen$ive tow when I had my van less than 2 weeks and got the right side wheels into the snow berm at the side of the road during a whiteout. With the axle unlocked, the right front wheel just dug itself deeper, while the left didn't pull. Locking the front axle allowed driving out.

John Tarr
oldfart3 is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

» Sportsmobile Registry

Clyde

ormtnbiker

The Yeti

TexGX
Add your Sportsmobile
» Featured Campgrounds

Reviews provided by

Powered by vBadvanced CMPS v3.2.3
Disclaimer:

This website is not affiliated with or endorsed by Sportsmobile SIP or any of its affiliates. This is an independent, unofficial site.


All times are GMT -6. The time now is 01:55 AM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2024, vBulletin Solutions, Inc.