UZJ100 4x4, 4wd system explained

[SALTY METHODS]

I'll take the stock 98-99 rear locker over ATRAC any day. Just put a locker up front and you will be triple locked with selectable locker controls front and rear and be done with it. You can do it cheaper than $2500 (prob $1500) if you aren't regearing and just adding the front locker. Get out and wheel the 100 for a weekend and I think you will find it is a lot more capable than you realize.

I agree.. If your concern is the front diff, then upgrade it and your problem solved. If you're that concerned that the 100 is weak then go buy a purpose built rock crawler. But i think your hunter clients' comfort will be cr@p by going with your second option.

 

[duggy]

IMO, you're giving the ZJ more technological credit than it deserves. Not saying you haven't seen a limited slip diff sending some torque over to a non-slipping tire, but a '97 Quadratrac isn't going to have any kind of electronic traction control...and a front limited slip on a Laredo is going to be a rare bird...traditional clutch pack front LS on full time 4WD is fairly rare on anything as they are not not transparent on pavement and adversely effect handling. Although the NV249 is apparently 80/20 rear/front biased in 4HI, so it's still within the realm of possibility. LS rear with V8 is fairly common.

So, not saying it's not a very capable rig, not saying it's more or less capable than your 100, but there is nothing magical going on. You put it on that roller test and it will sit there. With near 0 torque for the 16 year old clutch packs to transfer a portion of over to the other wheels...it's not going anywhere. Obviously it works pretty dang good in the real world...but that should just make you realize that while these roller tests show how effective the technology is in theory...real world application is completely different.

Anyway, I'm with the other guys, the only way you will find out if the 100 is capable of running whatever trail the ZJ has been down is to try...preferably with a buddy to avoid ruining a day with long self recovery...
So, could only find a few vids with a search of Skyline Alabama...

http://www.youtube.com/watch?feature=player_detailpage&v=KbeSidaBBkk#t=49

Is this the kind of terrain we're talking about? If so, that's some fairly technical stuff there that will probably prove to be somewhat challenging...

And not to kick you while you're feeling down about your rig, but make sure you search out front diff failure before applying judicious skinny pedal out in the middle of nowhere...

I watched the video. It does seem like some great technical terrain out there but the guy in the yellow FJ needs more experience behind the wheel on the trails. He should have bumped the ledge like the guys were telling him to do.

 

[sleeoffroad]

Here is a good primer on diffs and how they work. http://www.lcool.org/technical/diffs/diffs.html

Any traction control system that uses brakes to stop spinning wheels work to a point, until the going gets tough. Unless you can turn it off, you will get stranded since the brake application will prevent you from applying power to the ground. Granted systems designed lately is a lot better than the old systems designed in truck in the early 90's. For the most part they all work pretty well in rutted roads or situations where you have small sections of lost traction and you want to carry forward momentum. Stick in in some serious situations where you get bound up, it does not work.

Any system that "sends power" to the wheel with traction is mostly marketing fluff to try to sell a system to the masses.

The only think that works against the 100 is weight. I would put a 100 with rear locker against any Jeep with gizmo's for traction control. I would put a locker in the front for reasons that are explained in a lot of threads in this section.

 

[Nottajeep]

The only think that works against the 100 is weight.

And the front IFS...

 

[Jody Highroller]

Just to clarify. Last hunting season I took my 99 UZJ100 up Skyline via Smalligan's. Followed uncle's ZJ 5.2 Laredo. When we hit the long steep, muddy inclines my rig starts spinning. Now, I had some michelin street tires. Since then I have the treadwright Guard dogs and i have not been back yet. we shall see what she does. Btw these guard dogs straight up dig!

 

[duggy]

Haha, yeah...no off roading at all. In fact all city life in good ol Skyline. Never seen a trail or a 4x4 unlike you.

Lol, not quite. I will attempt to route this thread back on track. Why are you comparing a truck with street tires to one with mud tires? You're not being fair in this comparison, unfortunately.

 

[Trunk Monkey]

Back to tech please. Woody's warned a few of you about derailing threads. Jody, please use the multi-quote or edit buttons instead of posting repetitively, it keeps threads much cleaner.

 

[Jody Highroller]

Common ways IFS axles break

Here is a good primer on diffs and how they work. http://www.lcool.org/technical/diffs/diffs.html

Any traction control system that uses brakes to stop spinning wheels work to a point, until the going gets tough. Unless you can turn it off, you will get stranded since the brake application will prevent you from applying power to the ground. Granted systems designed lately is a lot better than the old systems designed in truck in the early 90's. For the most part they all work pretty well in rutted roads or situations where you have small sections of lost traction and you want to carry forward momentum. Stick in in some serious situations where you get bound up, it does not work.

Any system that "sends power" to the wheel with traction is mostly marketing fluff to try to sell a system to the masses.

The only think that works against the 100 is weight. I would put a 100 with rear locker against any Jeep with gizmo's for traction control. I would put a locker in the front for reasons that are explained in a lot of threads in this section.

Are you familiar with the most common basic conditions/actions that result in the 98-99 UZJ100 IFS (4 pin diff) Axles breaking? Is it big rock crawling or spinning through mud, ruts?

 

[ClankBang]

Its not the Axle its the spider gears in the diff.
I have seen it happen in loose gravel. Pretty much any time the tires spin I would worry about it.
You will know when it happens.
If I had one and planned on wheeling it I would save my money and throw an ARB up there before I did anything else.

 

[paflytyer]

Are you familiar with the most common basic conditions/actions that result in the 98-99 UZJ100 IFS (4 pin diff) Axles breaking? Is it big rock crawling or spinning through mud, ruts?

Do a little research on here and you'll likely learn all you need to know. For starters, the 98-99 you're talking about has a 2-pinion diff, not a 4-pinion.

http://www.sleeoffroad.com/newbie/newbieUZJ100.htm

 

[kennyao30]

Are you familiar with the most common basic conditions/actions that result in the 98-99 UZJ100 IFS (4 pin diff) Axles breaking? Is it big rock crawling or spinning through mud, ruts?

Skinny peddle with tires spinning, while one tire stops suddenly .....will break more diffs than anything else.

 

[KlausVanWinkle]

My friends blew when the rear diff was stuck on a rock, Passenger front tire was in loose dirt, the other was on a rock and then the passenger front tire suddenly got traction.

Yeah the 100 doesn't have a LSD (except the 98-99 LX) like the Jeep ZJ, but if you upstage your front diff you'll be triple locked and have stronger axles and diffs and be in a better truck. It's only like $1000 upgrade if you do it yourself. $1500 if someone else installs it. ARB usually gives you the compressor when you buy a locker.

 

[SmoothLC]

Thought of this thread when venturing over to ExPo today.

Looks like the 3rd edition of Four-by-Four Driving just came out.

May have to get me a copy for Christmas in order to slice through "the marketing jargon".

Update: Reading the book review on Overland Expo, according to Mr. Sheppard "there are basically just three" four-wheel-drive systems. "The profusion of trademarked drivetrains are all just slightly tweaked variations on a trio of themes." Looks like an interesting read.

 

[Muddy Bean]

Someday, with four electric motors running individual wheels, they will be computer controlled and we won't have a need for lockers...just send power to every wheel that has traction and save the batt juice on the one that's spinning until it gains traction. Done. No center diff...no driveshaft.

 

[KlausVanWinkle]

Someday, with four electric motors running individual wheels, they will be computer controlled and we won't have a need for lockers...just send power to every wheel that has traction and save the batt juice on the one that's spinning until it gains traction. Done. No center diff...no driveshaft.

I've been saying that for years. Get a diesel generator under the hood to recharge the batteries between the frame rails. Also some solar film, regenerative breaking and regenerative shock absorbers....

 

[Muddy Bean]

Doing it!! Let's go Klaus. We will be rich. I can already see myself swimming in the riches!!!

 

[stonepa]

I've been saying that for years. Get a diesel generator under the hood to recharge the batteries between the frame rails. Also some solar film, regenerative breaking and regenerative shock absorbers....

Didn't Toyota recently announce that the next Land Cruiser for the US would be a hybrid? At that point I may consider finally replace my 100 after 20+ years of enjoying it.

 

[Muddy Bean]

2016. Hopefully it will drastically improve mpg numbers.

 

[woody]

Update: Reading the book review on Overland Expo, according to Mr. Sheppard "there are basically just three" four-wheel-drive systems. "The profusion of trademarked drivetrains are all just slightly tweaked variations on a trio of themes." Looks like an interesting read.

Look forward to the review

http://www.drivingfast.net/off-road/technology/four-wheel-drive-system.htm

Good article that covers the basic three systems. I suspect this book will largely mirror the above link.

 

[revoked]

Someday, with four electric motors running individual wheels, they will be computer controlled and we won't have a need for lockers...just send power to every wheel that has traction and save the batt juice on the one that's spinning until it gains traction. Done. No center diff...no driveshaft.

Who's going to be the first one to lift a Tesla Model X?