JeepForum.com

JeepForum.com (http://www.jeepforum.com/forum/)
-   WJ Grand Cherokee Forum (http://www.jeepforum.com/forum/f310/)
-   -   When to use 4LO (http://www.jeepforum.com/forum/f310/when-use-4lo-1590801/)

smcutter 09-15-2013 11:46 PM

When to use 4LO
 
I searched this forum and browsed the first two pages of results without satisfactory answers, so here goes...

My buddy has a 2002 WJ Laredo with the V8 and auto tranny. His transfer case provides for 2HI, 4FT, 4PT, and 4LO. He usually sticks to 4FT while offroading, even when he's only crawling 2-5mph. Since I'm coming from a Wrangler with a manual transmission, I feel like it would be much easier on his tranny (specifically the torque converter) if he put it in 4LO for his crawling.

His V8 is definitely putting out enough torque that he doesn't need to be in 4LO to get over any rocks, so am I just unnecessarily worried about his torque converter being stressed by the slow speeds? Do y'all find that 4FT in an automatic is the best way to go for slow offroading?

troy70 09-16-2013 04:22 AM

I'm not a crawler (yet), but I do hit some decent mountain trails and snow. I have the NV-247 (no 2wd/4pt options), and I run the by the rule that you only use 4lo when you have to. About the only time I use it predictably, is to help control my decent when coming down steep mountain trails, reducing the load on the brakes.

MattJeep 09-16-2013 05:29 AM

I'm in 4lo as soon as I'm offroad. For the most part.

alfaitalia 09-16-2013 06:21 AM

Only when I get stuck and cant move in 4Hi!

WJ4x4LIFE 09-16-2013 06:47 AM

I would not suggest the use of 4Lo all the time, it does put a strain over time on a drivetrain of any condition. My opinion is to use the 4FT or 4PT, it would be a safer strategy with minimum wear and still enjoy one's self. I use 4PT, and it does just fine. The only time, I have use my 4Lo was during the test drive before I purchased it about two years ago. Now, do not get me wrong you need not to forget about it there, but do from time to time use it, so that nothing sticks when you do have to use it. keep up with maintenance on it anyway, whichever way you decide to use the four wheel drive option.

Idano12 09-16-2013 07:18 AM

Quote:

Originally Posted by troy70 (Post 16043089)
I'm not a crawler (yet), but I do hit some decent mountain trails and snow. I have the NV-247 (no 2wd/4pt options), and I run the by the rule that you only use 4lo when you have to. About the only time I use it predictably, is to help control my decent when coming down steep mountain trails, reducing the load on the tranny and brakes.

4 lo will always be easier on your tranny and the progressive coupler in your 247 transfer case.

MattJeep 09-16-2013 07:32 AM

Ya I disagree completely. Everything is easier offroad when in 4lo. I used to be a 4hi until stuck guy. Changed that when I got the TJ. It doesn't really have the power to motor over things when in 4hi, I would feather the clutch a whole lot less when in 4lo, and it would take the stress off the dana 35 by splitting the duty. I spent a week offroading in CO and went into 4lo pretty much as soon as I hit the trailhead. The 4.7 HO obviously will be better but i still expect to be in 4lo most of the time.

COL 09-16-2013 07:58 AM

Here is some quotes from an article I found online that states the uses of the different 4wd systems nicely. "Here's a 4WD how-to to help you get to know your four-wheel-drive vehicle:
here are several different types of 4WD systems. The two most common include full-time 4WD and part-time 4WD.

Full-Time 4WD means the vehicle is always making power available to all four wheels, typically shifting the power from the front and rear axles as necessary. Full-time 4WD offers maximum traction under all conditions, and does not require additional input from the driver (to turn on or off). Due to the nature of a full-time 4WD system, you'll find the vehicle does not have the overall on-road mobility of a part time 4X4 package.

Part-Time 4WD means the vehicle has a means to select between 4WD and 2WD. It could be a lever or it could a switch. With this setup, you shift between 4WD and 2WD on the go. A vehicle with part-time 4WD provides superior traction on slippery surfaces because the front and rear sets of wheels are (obviously) locked together. It's important to note that vehicles with part-time 4WD systems should not be driven on dry, smooth road surfaces when in 4WD mode. The constant use of 4WD under these conditions can damage drivetrain components."

"High-Range 4WD
4-High allows you to drive full speed, if necessary (keeping in mind the caveat mentioned earlier regarding driving on dry pavement). The high-range ratios in 4WD mode are the same gear ratios as the vehicle has in 2WD mode.

When to use 4-High: Additional traction when the terrain isn't steep; snow; ice; muddy roads or when operating where there is no road; rocky, gravel roads; when stuck in sand or snow; under extremely slippery conditions.

Low-Range 4WD
4-Low alters the gearing in your vehicle. It is designed so you can creep along at slow speeds (which also reduces the potential for damage to your vehicle). Most manufacturers recommend you do not exceed 45 mph in 4-Low. Keep in mind that 4-Low does not provide more traction. Instead, it provides considerably more torque (often 2-3 times that of 4-High at very low speeds).

When to use 4-Low: On wet, slippery surfaces; in heavy, wet snow; climbing or descending steep hills; on very rough terrain (trails, off road); powering through mud; climbing rocks; driving through deep sand; fording water."

"Four Wheeling Tips

Most systems can be shifted into 4-Low as the vehicle is moving forward very slowly at 1-2 mph with the transmission in neutral. Alternatively, you can stop the vehicle completely and engage 4-Low. Wait for the drive system lamp to stop flashing before shifting the transmission into gear.

To shift back from 4-Low to 4-High, slow to 1-2 mph with the transmission in Neutral. Wait for the drive system lamp to stop flashing before shifting the transmission into gear.

Always engage 4-Low before you need it, and if you're in doubt about the conditions, slow down and select 4-Low.

Never operate 4WD on hard dry surfaces. Jeep's 4FT can be operated on hard dry surfaces without ill effect to the drivetrain. Fuel economy may be slightly lower in this mode.

If the vehicle has an "Auto" setting, it will prove ideal for use when road surfaces vary (for example, wet or dry, snowy or dry, etc.). Typically, driving in this mode results in slightly lower fuel economy than the 2WD mode.

Even with 4WD, slow and steady is much more important than fast and aggressive.

When in 4WD, the front wheels will feel as if they are "pushing" or "skidding" in a tight turn. Don't worry! This is normal.

Treat loose or wet surfaces as if they are ice. That means you should do everything (brake, accelerate, turn) slowly and gently. This approach keeps the tires from spinning on acceleration and it also keeps them from locking up on deceleration.

If you have driven through deep water or mud or deep wet snow, apply your brakes several times at low speed to dry them out. Keep in mind that water, mud and deep snow will affect brake operation."

Pedro7 09-16-2013 03:53 PM

Quote:

Originally Posted by MattJeep (Post 16045265)
Ya I disagree completely. Everything is easier offroad when in 4lo. I used to be a 4hi until stuck guy. Changed that when I got the TJ. It doesn't really have the power to motor over things when in 4hi, I would feather the clutch a whole lot less when in 4lo, and it would take the stress off the dana 35 by splitting the duty. I spent a week offroading in CO and went into 4lo pretty much as soon as I hit the trailhead. The 4.7 HO obviously will be better but i still expect to be in 4lo most of the time.

X2, I'm usually in 4 low as much as possible. Unless its an easy green trail I'm in 4low. It makes it so much easier, a lot of times I barely have to hit the gas on some of the easier trails and it just crawls right along for me. However, I don't wheel much mud. Regardless, why not just start in 4low if you think you might get stuck?

smcutter 09-16-2013 04:07 PM

Thanks for all the feedback, guys! It seems the consensus is that he's not going to stress anything in 4FT, so if he prefers that over 4LO then there's no reason for him to do otherwise.

MuddyWJ 09-16-2013 04:19 PM

FT will get you stuck more often than not when off-road. Especially with open diffs. It sends power to the wheels with the least resistance. 4h with the v8 works great because of the gearing and torque. I use mostly part time while offroading( high or low depending on the situation ) If he's okay using FT so be it, won't hurt anything.

CRJEeP_wj 09-16-2013 04:35 PM

4low and 1st gear anytime I'm in rocks, snow or anything technical. 4 hi and 2 usually on 35+ mph loose dirt rocky roads. I never use drive or over drive in 4wd to keep my transmission from shifting constantly as the terrain/speed changes.

narnwv 09-16-2013 05:55 PM

Quote:

Originally Posted by smcutter (Post 16059249)
Thanks for all the feedback, guys! It seems the consensus is that he's not going to stress anything in 4FT, so if he prefers that over 4LO then there's no reason for him to do otherwise.

Just so your buddy knows, 4FT--is OPEN in the transfer case. 4H-PT is the same as the 4-high in your Wrangler. With 4FT, he can drive on dry pavement--but off road, if one wheel looses traction, all power goes to that wheel.

smcutter 09-16-2013 06:01 PM

Quote:

Originally Posted by narnwv

Just so your buddy knows, 4FT--is OPEN in the transfer case. 4H-PT is the same as the 4-high in your Wrangler. With 4FT, he can drive on dry pavement--but off road, if one wheel looses traction, all power goes to that wheel.

Yeah, we both get that. The wheeling he usually does is mostly just slow driving but with plenty of traction. Dry dirt roads with heavy washout, sharp shelf roads, etc. so having his center diff unlocked is definitely better in those situations.

For my part, I'm actually considering getting the Teraflex kit that allows me to have a 2LO option in my Rubicon transfer case. I'd say 80% of the time I'm in 4LO is simply because I need to go slowly, not because I need extra traction.

narnwv 09-16-2013 06:18 PM

that's cool. We get a LOT of people that get them backwards 'round here.


The time now is 09:55 PM.

Powered by vBulletin Version 3.8.4
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.