FROM: someone@someone.com (Someone) SUBJECT: Re: Question on Locking Hubs & Limited Slip Diff. DATE: Wed, 30 Jun 1999 21:41:54 -0400 ORGANIZATION: Interlog Internet Services NEWSGROUPS: rec.autos.4x4 >>Statement: >> >> The front hubs lock automatically when you need them, but there are no >> locking or limited-slip differentials in Suzukišs system. >> >>Explantion: > >>I donšt understand this, please explain if you can. > >>Are they talking about when the vehicle is NOT in 4 wheel drive? >No, they mean when engaging 4wd....hubs are on the outside, diff is in the >middle. >Note though that you must have those hubs engaged/locked *before* you >switch into 4wd at high speed....there *are* some exotic systems that are >able to spin the front drive train up to the necessary speed, but AFAIK, >the Vitara (or any other Suz) isn't one of those. > >And, if one of the front wheels does NOT have traction, I will still get > >out because the hubs are locked to the axle, and thus the same amount of > >power is applied to both front wheels, so the front wheel with the > >traction should get me unstuck. > > Nope, same situation as in the rear, once the left wheel looses traction > the right one doesn't get much torque either....all an open diff does (can > do) is to split torque evenly between left and right....if left = zero, > then right = zero too.... > > >So to ge stuck, as I see it, I would have to lose traction on both front > >wheels, and at least one rear wheel? > > Nope, one front, one rear. Front is no different than rear, both are open > diff's in most stock configurations....and *when* there are factory options > (LSD or locker), then it starts with the rear, in which case you would need > loss of traction on both rear wheels and one front wheel. > > >Does anyone know if the JEEP TJ has limited slip differentials? > > Think so, and if not, then heaps of aftermarket (also lockers). Thanks again for the clarification. But something still puzzles me. In the article, the reviewer specifically says that the ŗfront Hubs lock˛, and thus in some way are different than the back. How then, are the front different than the back? Can they front hubs lock, in some other way, than a locking differential or limited slip differential? And also, with the Suzuki, you can shift on the fly into 4WD,thanks to the Grand Vitaras 2-speed transfer case... so the catalogue says. I didnšt find much technical information at Suzukišs web site on this, kind of disapointing. Thanks again. FROM: brucegb@bga.com (Bruce Burden) SUBJECT: Re: Question on Locking Hubs & Limited Slip Diff. DATE: 1 Jul 99 03:47:17 GMT NEWSGROUPS: rec.autos.4x4 Someone (someone@someone.com) wrote: : In the article, the reviewer specifically says that the front Hubs lock, : and thus in some way are different than the back. : Once upon a time, 4x4 vehicles had the front wheels permanently connected to the front axle shafts. Then somebody said, hey, wouldn't it be cool if... and the locking hub was born. This is a mechanical device that you twist to mechanically connect or disconnect the front wheels from the stub axle (the one connected to the CV or U joint). Later, Jeep said, hey, would it be cool if... and the "automatic hub" was born. There really isn't anything "automatic" about the hub, it is a throwback to the earl days, where the wheel is permanently coupled to the stub axle. The difference is that there was an axle disconnect somewhere so the two front wheels aren't coupled together. This works, more or less, depending on the system (ie, really cold days could make engaging inreliable [GM], vaccum motors [big 3?, as in vaccum leaks], and other means I am sure). For the '99 models, Ford (and the Mazda clone) introduced a true locking front hub, under the name Pulse- something-or-another. From what I understand, this is a true automatic locking hub. : How then, are the front different than the back? The rear wheels are permanently coupled to the axle. It is possible to install locking hubs to a full-floating rear axle, but I understand it is not really recommended (front axles are, by design, always full floating units. This means the axle doesn't have any role in holding the wheel in place. All the axle does is turn the wheel.) : Can they front hubs lock, in some other way, than a locking differential : or limited slip differential? Terminology problem here. Well, no, not really, I suppose. Whether you are talking about locking the front hubs of the front differential, you are talking about mechanically coupling the unit in question to an axle shaft (or, in the front diff, the OTHER axle shaft). Look at it this way. With manual hubs, you can turn the axle and not turn the wheels if the hubs are unlocked (and, obviously, vice-versa). With an automatic axle connect system, and a locking differential, you will turn one wheel (the one that is not disconnected, obviously). The disconnected wheel won't turn. : And also, with the Suzuki, you can shift on the fly into 4WD,thanks to the : Grand Vitaras 2-speed transfer case... so the catalogue says. Some of this is marketing. If you have manual hubs, you can probably shift into 4WD "on-the-fly", but it won't do any good if the hubs are unlocked. If the hubs are locked, and you are going nearly straight, with no wheel spin, you can "shift-on- the-fly" as well. Some vehicles have a transfer case equipped with sometype of clutch or differential, and "shifting-on-the-fly" simply locks up the clutch (to a greater of lesser extent, depending on the design) and they may/may not engage the front axle. The newer "all-wheel drive" 4x4's and autos run with the front wheels always coupled to the axle, hence, the may/may not engage the front axle. Bruce -- ------------------------------------------------------------------------ "I like bad!" Bruce Burden Austin, TX. - Thuganlitha The Power and the Prophet Robert Don Hughes