Rlmx

Trying to understand locking hubs.

I get what happens when the hubs are locked. With locking hubs, the wheels are locked into the axle (assuming that both [non-auto locking] hubs are engaged by the driver/user).

But I guess the difference (vs. a locker) is that both wheels just roll in unison with the axle, vs being turned in unison (aka receiving power from the engine through the drive train) by a locker?

tinytrax78

a lock out hub or auto lock hub connects/disconnects the axle at the hub (at the wheel ) it can only put out power that is received from the differential (center of axle) witch can be open, locking, or limited slip when you refer to a locker that is in the differential (and is a traction adder that make both wheels spin instead of a open differential that only puts power to the wheel that spins easiest) when you refer to lock outs those are at the wheel and only lock in that wheel im sure more ppl will chime in and help you understand but you might look on youtube for a video

Rlmx

So when used with an open diff, is the non-spinning wheel nothing more that a drag on the "system." With the OD, the formerly non-spinning wheel is forced to turn with the spinning wheel given the locking hub... but is the torque delivery to the ground different on what would have been the non-spinning wheel?

Forgive the lack of use of appropriate terminology, I am an IT guy, not a mechanic, nor a mechanical engineer.

00t444e

All a locking hub does is connect the wheel to the axleshaft so It will get torque from the differential. The hubs on the front of our Jeeps are full time hubs, which is equivlent to having the hubs locked on a vehicle with locking hubs.

Rlmx

So maybe this is why the new Cherokee's are advertised as having "permanent locking hubs?" Have learned something new here.

1976gmc20

Well, sorta, kinda ...

On a Cherokee (and also all FWD cars, and other modern 4WDs with independent front suspension) the male splined axle shaft fits through a female spline in the middle of the hub bearing assembly, and is secured with a big nut (which only holds the axle into the hub; the hub itself is mounted to the steering spindle). Only difference is the older Cherokees had a "solid" front axle as opposed to IFS.

Manual locking hubs were found on all* the older 4x4 pickups and many/most earlier Jeeps including Wagoneer, Gladiator, CJs, etc and currently possibly on some medium duty 4x4 trucks. A manual locking hub has a third doughnut shaped piece with both female and male spines that can either connect the axle shaft and the wheel hub, or be slid out of the way to only connect one of those so the front wheel hub can freewheel much like any old RWD 2wd car/pickup. That's the somewhat simple explanation. The old locking hubs had serviceable bearings that you could remove after unscrewing a double set of ring-like nuts that go onto the hollow spindle, while all the modern hubs (including XJ) have sealed bearings. None of this may make any sense if you don't have any mechanical experience at all.

Locking differentials are something completely different, but often found on 4WD vehicles. A normal "open" differential has gears that allow inner and outer wheels to go different speeds on a driven axle when you go around a corner. Unfortunately, they also allow one wheel with less traction to spin limitlessly while the other side doesn't turn at all. This commonly happens if there is a difference in road camber between front and rear axles and is commonly referred to as being "stuck" - LOL. A locking differential when engaged just forces both wheels to turn at the same speed so you either drive out of the situation or now happily spin both wheels and still be stuck.

Solid axle Jeeps like the old Cherokees have suspension capable of flexing with the road camber (up to a point) and so keep the weight equal on all four wheels and mostly avoiding the open differential allowing one wheel to just spin problem. Even stock Cherokees are truly amazing.

* Actually, early 4x4 Jeeps/pickups did NOT have locking hubs, but instead had a connecting piece bolted into the outside of the hub assembly. These would qualify as "permanent locking hubs." Then along came companies like Warn (I believe that they were the first) with an aftermarket assembly that replaced the "permanent locking" piece and allowed you to "un-lock" the front hubs (in the manner described above) for extended highway use, ostensibly to save gas and wear on the front axle. Ironically, "modern" 4WDs have gone back to letting everything turn all the time or actually driving the front end via AWD or "full time 4WD."