4WD or Not?

[Ultima Thule]

So here’s my question:
I have a 2021 JL Rubicon, it is my third or fourth Jeep, and I dearly love it. 2.0 Turbo/8-speed, 4.10’s. Totally stock Rubicon. I haven’t found anywhere I wanted to go that I can’t in this thing, so no modifications yet.

We do our off-roading more as “overlanding” or adventuring. As we call it “Where Does This Road Go?” And no body damage permitted.

So, we do a lot of forest service roads, barely maintained gravel and such in the East Tennessee/Western North Carolina area.

I find that quite often the speed I want to travel is slower than the road allows coasting downhill, and I end up dragging the brakes in 2WD. Would it be easier on the Jeep to shift into 4HI or even 4LO and let the engine braking maintain my speed? Often there is no need for me to be in 4WD for the traction, but since the Jeep doesn’t have a 2LO like my F-250, I just wondered if you folks cruised gravel forest service type areas in 4WD to be able to use the speed control/downhill descent control, and sway bar disconnect, even without the need for traction?

Thanks for helping a noob!
Ultima Thule

 

[TripLeader]

I have, and do, use 4 low for speed control on descents on dirt and rocks, even when there is no need for traction.

 

[Peter_n_Margaret]

Any time off the black top, 4WD will provide better braking, better handling and less damage to the tracks.
And reduce your tyre pressures for more of all the above.
Cheers,
Peter
OKA196 motorhome

 

[Ultima Thule]

Any time off the black top, 4WD will provide better braking, better handling and less damage to the tracks.
And reduce your tyre pressures for more of all the above.
Cheers,
Peter
OKA196 motorhome

Much of the washboard type damage we see is from dummies gassing it up hills and rutting it up as they bounce. Do you disconnect the sway bar also? Easy push of a button on my Rubicon.

 

[zgfiredude]

Two thoughts: One, I find myself from time to time wishing I could keep the sway bar unlocked while either above 24 mph or in 2 wheel drive. Both of those things will attempt to re-lock the sway bar (terrain dependent).....So I'd say yes to unlocking the sway bar perhaps more than you have. Try it and see if it suits your situation. Second thought is have you tried manually shifting the auto? I will do that frequently when in hilly terrain up or downhill for more control.

 

[NatersXJ6]

In the situations you are describing, a fair number of people, me included, find the 4:1 Rubicon case to be “too low”. I’m generally completely happy tooling along as 5-6 mph, but often 15 would be a more reasonable speed, and that is too fast for my JK in low range. Your best bet is probably 4 high and second gear and light throttle. My experience driving JLs for several weeks left me unimpressed with the engine braking capabilities, small turbo engines just don’t brake well.

 

[Herbie]

Any time off the black top, 4WD will provide better braking, better handling and less damage to the tracks.
And reduce your tyre pressures for more of all the above.

I regret that I have but one 'like' to give to this post.

Yes, 4-Lo is better than riding the brakes. Yes, 4WD is kinder to the trail. Yes, airing-down is kinder to the trail, and the vehicle, and your backsides.

 

[SDDiver5]

If we're talking engine breaking, why not use 2nd or 1st gear to go down a hill?

Different application, and I have 4.56 gears, but if I go into 4 low in my truck it barely moves and I have to give it some throttle. And I only use that on very steep and rocky trails. All other times and depending on the grade I use tow/haul, 2nd or 1st and let the engine do the work for me.

 

[Herbie]

If we're talking engine breaking, why not use 2nd or 1st gear to go down a hill?

Different application, and I have 4.56 gears, but if I go into 4 low in my truck it barely moves and I have to give it some throttle. And I only use that on very steep and rocky trails. All other times and depending on the grade I use tow/haul, 2nd or 1st and let the engine do the work for me.

Yeah, it all depends on the drive ratios involved. On my Astro van (30" tires, 4.10 gears), 4Hi/1st was still sometimes too fast for downhill or tricky terrain, so I was constantly on the brakes, where as with a 2.72:1 Low in 2nd, it was easily moderated with slight or zero throttle. In 4Lo/1st the van would idle at a nice walking pace and even climb slight hills without throttle.

On my new truck, I'm still re-learning everything. Even with 3.73 gears, the 10-speed has such a short 1st that I've only reached for the 4Lo knob on one very tricky hillclimb so far.

 

[billiebob]

Would it be easier on the Jeep to shift into 4HI or even 4LO and let the engine braking maintain my speed? Often there is no need for me to be in 4WD for the traction, but since the Jeep doesn’t have a 2LO like my F-250, I just wondered if you folks cruised gravel forest service type areas in 4WD to be able to use the speed control/downhill descent control

ALWAYS,,,, I shift into 4WD way more often than others think is required.

A Toyota ad for a 4WD Tercel in the 1980s..... had an impact on my attitude forever.

On any given road if 15HP will spin a tire due to snow, ice, rain, gravel, grade.... 2WD means you spin tires at 30HP..... 4WD means you lose traction at 60HP...... same thing downhill, engine braking doubles with 4WD.

Think of 4WD as Tread Lightly..... often in 2WD you must spin tires to maintain headway. 4WD eliminates that traction loss and ripping up of the watershed. A lot of road closures are due to harm to the watershed. YES, definitely use 4WD whenever traction is limited.

PS, EDIT,
The option to traction is speed, momentum, and speed often breaks things.

 

[billiebob]

a fair number of people, me included, find the 4:1 Rubicon case to be “too low”.

EXACTLY !!!

I love my Rubicon when towing but never use 4L when not towing.

On my YJ tho I would run up the mountain to a forestry lookout in 4H in 2nd gear.... never shifting.... and come down in 4L in 3rd gear.... never shifting. That YJ had the dreaded 3.07 axles but in 4L it ran like a Mustang..... 4L and 60mph coming down a forestry road was an incredible drive.

I agree, the Rubicon 4L 4:1 ratio is a stupid low ratio unless you are climbing a waterfall. The Sport 4L ratio of 2.72???? is far more useable and way more fun.

PS, EDIT.... The Rubicon built for and named after the Rubicon Trail is the only vehicle in North America with the 4:1 Transfer case. Everything else for the last 100 years has had a 2.72:1 ratio or something similar. Unless you want to literally crawl OFF ROAD.... the Rubicon 4.00:1 ratio is a stupid low transfer case ratio. It makes sense for me towing a trailer.... It would be practical on an ambulance off road with a spinal injury victim.... but otherwise it is too low a ratio for most of us.

The Jeep Rubicon was built to give Jeep the bragging rights to being the ONLY factory stock vehicle capable of tackling the Rubicon Trail. It was a brilliant mrketing decision.

Some of the other features like D44 axles on both ends, same thing. A fully locked Rubicon might put ALL the torque to any single tire, front axle included. Before the Rubicon all 4WD vehicles in North America had lighter front axles than rear axles because in 4WD torque was 50% front axle, 50% rear axle but in 2WD ALL the torque went to the rear axle so the D60 rear, D44 front axles were common.

I love my Rubicon not for the 4:1 Transfer Case but for the selectable lockers and the D44 axles at both ends.

 

[billiebob]

If we're talking engine breaking, why not use 2nd or 1st gear to go down a hill?

The difference 4L to 4H is the range of speed available. 3rd 4L will narrow that speed range. 2nd, even 1st in 4H will often give too much speed range when descending a forestry road. Think of close ratio 4speeds vs wide ratio 3speeds from the 1970s. Far better control when the gears are closer together.

Going uphill tho is the opposite. 4H in 2nd gear will give a wide range of speed and let you blast up a mountain road.

 

[86scotty]

@Ultima Thule, I also have a 2021 JLU but a Willys and I also live and explore (some) in East TN/Western NC. I also have the 2.0 w/ 8 speed which I love. I also 'overland' more than I crawl, wheel or whatever they call it that they do at Windrock.

I have found the 8 speed automatic with the manual mode (manumatic or whatever they call that) to be extremely helpful off pavement, actually even sometimes on pavement. I use it to hold gears up slow offroad climbs and hold gears for downhill descents whether in 2wd or 4wd. Honestly though, since I also travel a lot and do more serious offroading in the Rockies I can't really think of many places in the east where you'd need to put a Jeep in 4wd. If it's wet or muddy, sure, but we just don't have much steep terrain.

Have you fooled around with hill descent control on your Jeep? I messed around with it a couple of weeks ago running around the Alpine Loop in Colorado but mostly found it too agressive. I'm sure it is really helpful in extremely tricky terrain or with less skilled drivers but I feel more in control using manual shifting in 4L for tough, rocky downhill trails.

Hill Descent Control

Hill Descent Control (HDC) has been available on Rubicon models for quite some time, but most people never use it!

jeeptourscolorado.com

 

[Peter_n_Margaret]

Apologies to those who have seen this before.
Coming down one of the many jump-ups on the Carson Track in the Kimberley, Oz.
First gear, low range, no brakes used and no accelerator used. The vehicle weighs about 6 tonns.
Always under control.

Cheers,
Peter
OKA196 motorhome

 

[billiebob]

Old video, Rubicon 4L down


and 4L up all locked, zero drama, zero throttle..... where 4:1 transfer case ratios rule