You can run "Full Time" even on dry ground, but it is not the same as "all wheel drive". Sorry they are confusing people, but now we know better.

Wow, thank you.

I have a 2003 Wj. Do you notice a loud rumble while in 4x4 full time?

@@maxd.m1183 I haven't heard anything like that. It usually switches pretty easy. also when you are in 4x4 fulltime there is a different sound than 2x4 but I wouldnt call it a "loud rumble" ....maybe make sure your diff has fluid

@@maxd.m1183 yes mine does that omg

@@cactusrider7686 Finally found someone who noticed this! I thought I was nuts

2003 WJ mine pops and sounds like it’s going to break apart in part time, 4 hi and low

Yes the new venture 242 also used in the Hummer

Very under rated. Granted my 96 ZJ had quadra-trac full time 4WD and it went everywhere I took it, Selec-Trac just gives you the best of both worlds both full and part time 4WD. I now own a 98 ZJ with Selec-Trac.

Part time is to be used in continuously low traction conditions where full time 4WD can be left engaged year round if you wish regardless of traction conditions. In part time 4WD the front and rear axles are mechanically locked together with a 50/50 torque split regardless of traction conditions, and regardless of if you are turning or driving in a straight line. In full time 4WD the front and rear axles are no longer locked together they are a 48/52 torque split with an open center differential which allows differences in front and rear axles speeds to allow for turning on paved surfaces without binding up the drive train. Its a great system and one major thing I looked for when I got another Jeep. We get varying driving conditions in the winter here in Idaho where the roads continuously change from fully snow covered to patches of snow/ice where you'd typically need to be shifting into and out of 4WD going in and out of parking lots and parking spaces, the full time 4WD mode is great you just put it in full time 4WD and just leave it....if the snow/ice gets really bad you can of course select part time 4WD mode to give you a locked center differential and an even amount of power going to the front and rear axles. My Jeep has an added bonus of a rear limited slip differential so I get power to both rear wheels regardless of traction...helps a lot too in deep snow/mud. I hardly use the part time 4WD setting snow would have to get really deep to need it. I had a previous Jeep that had quadra-trac which was full time 4WD all the time no 2wd and no part time and I was amazed where that thing would go and how well it handled in deep snow...never got stuck and never felt like I was ever close to getting stuck and I had that thing offroad more than it was on the highway.

Remember, not every Jeep has both 4WD modes, so don't be confused if you only see 4WD High and Low.

DeathScouter Thanks. Yeah it has full time and part time on the shift. Thanks for the reply. ATB

Don't go by that necessarily either. Crawl under the vehicle and verify that it has a NV242 or NP242 on the T-case. Some people like to swap out parts but never bother to change the decals LOL. Doesn't happen often but it does happen, so be 100% certain.

I was under the assumption that there would be a pretty big difference in fuel economy driving in 4WD full time VS 2WD. My previous 96 Jeep Grand Cherokee had quadra-trac, so it was in 4WD all the time regardless, I would get between 14-17mpg in town, and 22-25mpg on the highway consistently. My current 98 Jeep Grand Cherokee has Selec-Trac, so figuring ok, it has 2WD it'll get a couple MPG better than my previous Jeep that was in 4WD all the time. The real world results are different than I was thinking. I may have maybe 1/2-1mpg by being in full time 4WD VS my current Jeep in 2WD. So with that, there isn't a huge difference between driving in 2WD VS 4WD full time, at least nothing to really give me a reason to drive in 1 mode vs the other to save fuel. I still use 2WD in my current jeep since its there and most times I don't need 4WD anyways, but its sure nice having the ability to chose. My Jeeps are the only 2 vehicles I've ever had that have full time 4WD, every other vehicle I've had/have is/was part time 4WD only, and I really like the full time 4WD feature as you don't have to shift in and out of 4WD when the road conditions are always changing...here in Idaho we get snow/ice and the roads are usually a mix of dry pavement, ice/snow/packed snow, so being able to use full time 4WD and just leaving it there when the roads are bad is really a nice feature.

You'd be surprised in real world driving that being in 4WD full time isn't going to hurt your MPG's.

Nice. I had no idea Selec-Trac was available on Wranglers. I have a 2013 JK and a 2013 JKU and my GF has a 2017 JKU... all Command-Trac

@@DeathScouter Yep. A lot of the people who watched my video were surprised at how smoothly the transfer case operated. Its my first Jeep ever, and I'm very much enjoying it. Already put on more than 95,000 kms...lol

The 50/50 split in part time splits the engine torque to the front and rear differentials. At 5:19 I explain open differentials.

I'm aware of the difference between a "locking" versus "open differential. If these Select Trac differentials are "open", as you so stated, then locking the "transfer case" has no impact on the front and rear differentials, and since the front wheels (and rear wheels) are not "locked" to each other on the same axle, the wheels are free to spin at different rates. That is why, regardless whether transfer case is locked, if this system was stuck with NO traction on both a front wheel and a rear wheel simultaneously, the front wheel and rear wheel with zero traction would spin (get all of the available torque, 50% to the Front and 50% to the rear because the transfer case is locked) and you would get stuck. To get unstuck, you would need to lock the rear diff or the front diff. If either front or rear diff had an LSD feature, that would also get you unstuck. Glad I was able to explain that for you!

No, you don't wanna switch it from 2wd to 4wd at freeway speeds. I've always slowed down to 5mph,then switched it. I have a Ford Explorer also. That one says on the back of the visor not to do more than 45 mph in 4wd. If road conditions are bad enough to need 4wd, you probably shouldn't be doing 45mph anyway. I prolly wouldn't be anyway 😆

That is correct

CORRECT, by splitting propulsion between the two axles, you take a lot of stress (wear) off of your rear passenger tire, which does most of the work on standard 2WD open-diff vehicles. 4WD FULL TIME is also said to prolong the life of your rear diff, for the same reason (although I don't know anyone wearing out diffs on the KJs). Thanks for watching!

In full time mode you really do that I run in 2WD most of the time but even at that you'll get slightly more wear on the rear tires as the front tires are just along for the ride as there's no pulling in 2WD mode of the front axle. We shall see how the tires last this way. My previous Jeep was quadra-trac so it was in 4WD all the time and never had any abnormal tire wear with that system and never rotated the tires. I kind of want to see how the tires do running in 2WD mode mostly and see how they do as far as wearing faster than the fronts.

Part time is for only on mud or snow and ice. Never on dry pavement called part time cuz it should NOT be used unless there is slippage. I was not getting it at first too.

@@gregj.gotham4402 that's not what my comment was referring to. It's about how he said the outside wheels can't slip but they can because there is no locker on the axles.

You won't get wheel hop because they are "open" differentials. 4WD locks the FRONT and REAR DIFFERENTIALS together, however, Jeep differentials (unless you bought a Rubicon edition) are still "open" differentials which means the LEFT and RIGHT wheels are not forced to spin at the same time. In fact, the wheel that has the LEAST resistance (like the one stuck in mud or sitting on ice) gets all the engine power (which is actually the OPPOSITE of what you really want to have happen). That is why people (usually Wrangler or Cherokee owners) will buy "lockers" for their differentials. "Lockers", "spools", or "limited slip" differentials force the LEFT and RIGHT wheels (as opposed to front and back differentials) to spin at the same time. FANTASTIC feature if you're off-roading... So the truth is that "4WD" is FUNCTIONALLY only "two wheel drive", being the Front Left and the Rear Right wheels. If you want "ALL wheel drive" then you need a locking/or limited slip differential, and then you will experience "chirping" or "wheel hopping".

In full time 4WD the front and rear differentials are not locked together mechanically by the T-case. Normally in full time 4WD mode you have a 48%/52% torque split between the front and rear differentials. Combined with a locking center differential in the transfer case it also gives you the ability to have part-time 4WD as well. The NP242 gives you the best of all worlds, 2WD, full and part time 4WD, neutral if you want to tow behind another vehicle without having to remove the drive shafts and don't need a dolly you can tow on all 4 wheels, and you also get low range for extra pulling power or for low speed maneuvers for offroad use or recovery.

Two different things. This video is describing how the transfer case distributes torque from front to rear. Lockers take same the front to rear part-time 4WD concept and apply it side to side. Lockers, if you have them, are located in the front and/or rear differentials. Lockers connect the wheels side to side, making a solid connection so both wheels on a given axle are forced to turn at the same speed. Lockers apply significant force to the axle, which is partly why a Rubicon has Dana 44s front and rear. So just like this video describes how part-time 4WD is only to be used off-road in loose or slick conditions, lockers are only to be used in off-roading when faced with an extreme situation on the trail, then disconnected after conquering that obstacle, because you don’t want to apply that level of force on you axles unless you really need it.

The selec-trac transfer case is a NP242, I'm not sure what the Liberty has, maybe the same one, but just go find an XJ with selec-trac and pull the t-case, unless you can find a Liberty with selec-trac then crawl under it and see if its the same NP242, the only issue I'd see would be the output shafts may have a different number of splines.

I get this in my 98 Jeep Grand Cherokee in full time 4WD mode, not nearly as bad as 4WD part time though. My 98 ZJ I guess has the heavier duty front axle in it as it has U-Joints rather than the CV axles that my 96 Jeep Grand Cherokee had...so I assume in my case its due to the U-Joints. If you have CV axles you may have a CV axle that is binding up, as is most likely the case with my U-Joints. Have no issue in 2WD, just in 4WD that it seems like its trying to bind a little bit in a tight turn, but I also have a rear limited slip so I'm not sure if that has anything to do with it or not either.

I know on the older Grand Cherokees you could swap them but I'm not sure if you can on the newer ones, the output shaft on the t-cases are different so you would have to do some parts swapping to get them to work.

I believe the Grand Wagoneer's system was a 2WD/4WD switch then hi/neutral/lo? I cannot recall for sure, but seems to me like some where like that and that was the earlier version of selec-trac, worked different and no full/part time mode, it was just a switch and lever system.

Actually I think I understand now, someone please correct me if I'm wrong -> The wheel in mud actually is easier to spin since it has no traction (It spins really fast but doesn't actually apply any torque to the road, so less power is used to spin it than the tire on paved road at a given speed) Thus all torque would go to this tire and the car would never move.

You're correct, the tire that SPINS THE EASIEST receives all the torque. This is FIXABLE if you install something called a "locker" (popular with Wrangler owners who do serious off-roading)

It make sense to me that it would since 4Lo is interlocking both axles just like 4-Part Time. I haven't worked on the GC so I don't have first hand knowledge of this model.

Thanks. You are correct. 2 modes are off road only. The light should say ‘Off ROAD’ instead of ‘part time’ it makes people think that in that position it switches between 2WD and all wheel drive automatically by sensing road conditions. I would not want such a thing anyway. It’s aJeep! I need to get an owners manual. Had Quadra-trac in my last Jeep. Loved it except for short tire life. This Select trac sticks in 4WD fairly bad on mine. I am going to change the lube to see if it helps. It’s not that big of a deal since I hardly put it in 4WD anyway with all my city slicker driving. My wife drives it the most.

Open front and rear differentials are pretty common in all 4WD vehicles. Some offer a limited slip rear differential, some offer one form or another of a locker in the rear differential, not very many offer a front locker but are usually an aftermarket option. Most likely your Jeep has open differentials. The Selec-Trac system has a lockable center differential in both the 4WD part time and low range position. In the 4WD full time position the center differential in the transfer case is unlocked which allows the front and rear differentials to turn at different speeds allowing you to drive on dry pavement and turn without causing any drive train binding problems that you would find if you tried those same turns in part time 4WD. I have a 98 ZJ Laredo Special Edition which was ordered with the rear limited slip option. It does pretty well in snow/ice but you still really want the additional pulling power of the front end (4WD) to help keep you going down the road straighter.

Most have open differentials, some give you an option for a limited slip rear differential, some give you lockers (Jeep Wrangler Rubicon). Lockers and limited slip differentials are all available in the aftermarket world though, if you need them. My 98 ZJ has selec-trac and a limited slip rear differential and an open front differential, its fine for most conditions and if you just drive on paved roads all the time having fully locked differentials can get you into some very interesting road positions if you aren't careful LOL.

Part time gives you a straight lock (no slippage) between front & rear wheels. In rough/extreme 4WD environments, it may be better have all 4 tires spinning to pull you up/out. But you are correct, in most cases Full Time is you "go to" setting.

Part-time locks the front and rear drive lines together giving a 50/50 torque split front and rear, its great in really nasty conditions such as deep snow, mud, sand, etc. My 96 ZJ had quadra-trac full time 4WD and it went everywhere I pointed it, and it didn't have lockers or limited slip, so with the selec-trac system 4WD Full Time would be somewhat the same, if you find that you can't get enough momentum in 4 Full time shift to 4 part time. Most of the time you'll find you can get through with full time 4wd though. My current 98 ZJ has selec-trac 4WD, haven't had a chance to play with it too much, and this jeep also has a limited slip rear differential so it gets a little better traction in 2WD mode so most of the winter last winter I never used the 4WD anyways. With most Jeeps regardless of which 4WD system you have you have open differentials, some of them had the option of limited slip in the rear, and if you had quadra-drive you'd get limited slip front/rear which they've done away with in the newer models and replaced it with the brake trickery system which uses the brakes to slow the spinning wheels, no actual limited slip in the differentials...and of course if you get into a Jeep Wrangler Rubicon you get electric lockers front and rear.

You can shift from 2WD into 4WD (NOT 4 Lo) at any legal speed (I'd recommend 50 MPH or lower). Check out your owner's manual for how/when to shift into 4Lo, and note that this is LIBERTY ONLY information. Other vehicles have different methods for shifting, especially for 4 Lo. Per the owner's manual (page 226) "NOTE: Shifting in or out of 4L is possible with the vehicle completely shopped, however difficulty may occur due to the mating clutch teeth not being properly aligned. Several attempts may be required for clutch teeth alignment and shift completion to occur. The preferred method is with the vehicle rolling 2 to 3 MPH. Avoid attempting to engage or disengage 4L with the vehicle moving faster than 2 to 3 MPH."

justgivemethedamnmanual.com/jeep-liberty-owners-manuals/

Between 2WD and both part time and full time high range modes you can shift in and out while moving, release the accelerator make the shift into the desired setting, then back on the accelerator. Same goes for shifting back out of either 4WD high range modes. Shifting to low range can be done while stopped but usually you find it won't engage until you move a little bit one way or the other, best way is to shift the transmission to neutral while moving a couple miles per hour then shift to low range then shift the transmission back into gear.

I had an XJ for years, and I could comfortably tool along at 65-70 all day long in FullTime

No speed limitations once its engaged, I believe they say you have to be going 55mph or less to engage it on the older models, but newer ones you can engage 4WD high range at any legal speed.

Its preferred because with the part time you get equal power to both the front and back making it easier to yourself unstuck typically

As far as I know, some Jeep products from 2002-2005 offered a FORM OF Posi that was marketed under the name "Trac-Lok". After 2005 the feature was essentially replaced with electronic traction control. I believe you can tell if your differentials have Trac-Lok by a metal plate/tag on your diff cover.

In Part Time 4WD he also confuses 'slippage' in the center diff with the work done by the front and rear diffs.

I don't know the answer. It would be in interesting experiment to do. Run 1 tank of gas in Full Time and compare.

DeathScouter has this been completed yet?? :)

Pat M it's not worth spending time worrying over..... use the 2WD option if available under normal highway driving conditions. In poor weather use 4WD Full Time. If you're in a foot of snow or mud use 4WD Part Time. If you're in really bad stuff, like stuck, or moving at 10-15 mph trying to crawl through deep snow or such, use 4WD Lo

Well, none in reality. My first Jeep was a 96 ZJ limited 4.0 Straight 6 with the quadra-trac 4WD, I usually got around 24mpg highway. I have a 98 ZJ Laredo SE 4.0 Straight 6 with Selec-Trac 4WD, same 24mpg highway in 2WD mode, and in full time 4WD. So in reality you don't lose anything.

My 1999 grand Cherokee averaged 10 mph consistently with the 6 cyl. My 2008 with the hemi did 10 around town 16 on the highway.

Thanks for watching. While AWD would technically denote thrust on all 4 wheels, "Full Time" would give you torque on the front and real axles at the same time (usually front driver's tire and rear passenger tires)... so yes. Its 1 step below AWD but on dry pavement, it would be pretty much the same.

Depends on the distance. If you tow a vehicle without disconnecting the drive shaft (or put the xfer case into neutral) then you're still spinning the transmission and without the engine running, fluid is not flowing for cooling purposes. Whenever you tow, you should put the Xfer case in Neutral, or disconnect the drive shaft if a vehicle doesn't have a Xfer case.

My 01 grand cherokee limited has selectrac with 4.7

@@hb91 is that.pretty fun having a v8 in a small vehicle like that...

It goes super good I believe it's faster than my 09 Z71 1500 silverado it runs 340 hp n jeep will lay rubber like nothing on dry pavement to I always wanted the Jeep cherokee limited v8 since 93n up but the 4.7 n 5.7 hemi are both faster n run better but come with different problems alot of people don't like 4.7 cause double timing chain but hands down way more responsive revs

@@Bennett-xo6iu way more fun n faster thanost

@@hb91 damn sounds fun.. well at least I know now they do offer v8 with the select trac 4wd system...

Same way as the selec-trac in part time. Its a 50/50 torque split so 50% torque goes to the front differential and 50% torque goes to the rear differential, regardless of if you are driving straight or turning, its just a part time system so you would have some drive train binding when turning on dry pavement with this system. Selec-Trac just gives you an open center differential allowing the front and rear drive lines to spin at different speeds when turning.

+Xbox360Gamer112 Select Trac

+DeathScouter With Command Trac, your transfer case options would be 2WD - 4WD (High) - N - 4WD (Low) Select Track "Part Time" is the same as Command Trac 4WD (High). What the Select Trac offers is the ability to drive in 4WD all the time.

+DeathScouter i know that I was just wondering what case you had. do you have the limited trim? or do you have a sport trim.

2003 Jeep Liberty Limited

LIMITED trim package. Selec-Trac 4WD on my rig

Running on 2WD puts 100% of the job of pushing the Jeep on the rear differential. If you run in Full Time, you would be splitting the load. However, in ANY 4WD "hi" modes, Mopar recommends top speeds of 55-60 MPH.

@@DeathScouter so i should not run it in full time over 60 mph? So if I'm on the interstate goi g 60/75+ I need to be in 2wd?

@@BRYKS22 Yes, that's my understanding, and a bit of a "logic' question, right? Why would you need 4WD if the roads permit you to be moving at such high rates of speed? Mopar sets a high speed limit for high-range 4WD. I would keep it under 55 MPH just to be safe.

@@DeathScouter yeah, the main reason I asked that was because I was looking at a jeep liberty forum and they guy was talking about how he got better mileage using full time vs 2wd but didnt mention the speed. Thanks alot buddy!!!

@@BRYKS22 I could see getting an improvement from Full Time because you have 2x the parts sharing the work... I would watch the high speeds though. Happy Jeepin' !