Wheeling in Four Wheel High
JK Enthusiast
Joined: Jan 2011
Posts: 323
Likes: 1
From: Portland Oregon
I've spent a lot of time on the beaches in mexico and I used 4hi most of the time BUT I always would air down to around 10-12 psi. Your engine/transmission works really hard in sand if the tires are hard and round. Low pressure adds more surface area.
Having said that, if your running up dunes or doing something stupid 4lo saves your transmission a lot of trauma. I over heated my transmission running in 4hi trying to climb a sand dune. Switching to 4lo solved that issue and I installed a transmission cooler the next weekend.
If you have a stock Rubicon like me then you know the pain of not being able to lock up without 4lo.. I tend to run in 4lo a lot more often now. Then again theres a big difference between the arizona deserts and the trees of oregon.
Having said that, if your running up dunes or doing something stupid 4lo saves your transmission a lot of trauma. I over heated my transmission running in 4hi trying to climb a sand dune. Switching to 4lo solved that issue and I installed a transmission cooler the next weekend.
If you have a stock Rubicon like me then you know the pain of not being able to lock up without 4lo.. I tend to run in 4lo a lot more often now. Then again theres a big difference between the arizona deserts and the trees of oregon.
JK Super Freak
Joined: Nov 2010
Posts: 1,053
Likes: 0
From: East Stroudsburg, PA
Are you running stock gears with those 35"s? If so that is probaly why you are overheating. The extra stress of trying to turn those meats in the sand is creating too much heat in the trans. Remember with an auto the torque converter is what allows for slippage, it will only lock at higher speeds where slippage is not needed. That slippage creates heat, that is more than likely why you are overheating.
JK Super Freak
Joined: Nov 2010
Posts: 1,053
Likes: 0
From: East Stroudsburg, PA
Low tire pressure creates MORE rolling resistance, not less. The bigger foot print creates more friction, ie, traction. Ever push a car with a flat tire or tires. which would you rather push.
JK Enthusiast
Joined: Feb 2011
Posts: 437
Likes: 1
From: Meredith, New Hampshire
True statement. However, in sand a fully inflated tire will spin more because it's not getting the traction you would if the tires were aired down.
Banned Member
Joined: Nov 2009
Posts: 767
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JK Enthusiast
Joined: Jan 2010
Posts: 405
Likes: 0
From: Alberta
Never had a problem with the tranny overheating in 4lo which I run most of the time when offroad. I got my first hotoil message last weekend and I was in 2hi driving up a forest service road. May have to start looking for aux cooler 
JK Enthusiast
Joined: Mar 2011
Posts: 270
Likes: 0
From: Cascade, Id
100% wrong!
Not 100% sure why you would go to 4 low on the beach or in a tough situation. 4lo adds more torque and pulling power, a.k.a. climbing. For instance, you get into a little mud, 4 lo will not allow you to spin the wheels fast enought to clear the tread on the tires to get grip. This is where I us 4 hi. The reason your trans is over heating is the lack of air flow that is coming through. I don't see how going to 4 low is going to be any different since your trans acts the same, it is your transfer case that shifts into the lower gear.
Unless you have a radiator thats clogged with mud, then thats another story.
JK Enthusiast
Joined: Feb 2011
Posts: 174
Likes: 0
From: Austin, TX
I can't agree with this... I run in 4Lo on the beach, mud and throughout the entire obstacle that I frequent. Your wheels spin fast enough in 4Lo to clear mud and it actually seems that it takes a lot less throttle to do so in 4Lo than in 4H... Also, for a manual, your better off in 4Lo while going through mud because of the water. In 4Lo, no clutch is needed to start your vehicle so you don't have to worry about mud or water getting in the clutch...