[alkaline747trio]

So, I can drop a bunch of cash on an ARB setup. Or I can drop a good chunk of cash and a bunch of time on an e-locker retro-fit. Or I can throw in an auto-locker, and eventually get locking hubs and the part-time kit.

I'm probably going to do the last one, and I'm definitely going to try it out before I go part-time. So don't waste your breath telling me it's bad. I know this. And I am going to install the part-time kit. But I just want to try things out before hand, you all know how I am. And I figured I'd ask to see if anyone else has done this, and could explain a little better what it feels like to drive.

[Lka1988]

I don't know what it feels like, but I can happily tell you what it will sound like when you try to turn:

clickclickclickpopopoPOPOPOPOPSNAPcrunchcrunchgrindmangledeath

[89GASHOG]

If you can afford an ARB, get one!

[NaterGator]

You'll crash or destroy the front end in short order. The first time you accidentally give it the slightest bit of throttle around a turn... clink!

[stinkyfj60]

I dont know if you would break the front end, or if you would create extreme driveline windup and no telling where it would snap....

[Elijah]

If we are talking AussieLockers, I don't think you would 'break the front end' or have 'driveline windup'. I think you would have a little more ratchet sound than the rear lunchbox locker and maybe a tire chirp now and then.

[bpassmore]

If you unlock the front hubs on the road, and only drive locked up off road, then you will drive for a long while (possibly) before breaking anything.
You might be able to run for a long time like that.

Just stay unlocked on the pavment.

Off-road you will have some pretty serious jerking in the steering wheel, and it will be pulling to the center all the time. You will need to keep your eyes open, and your hands tight.

[stinkyfj60]

Originally Posted by bpassmore

If you unlock the front hubs on the road, and only drive locked up off road, then you will drive for a long while (possibly) before breaking anything.
You might be able to run for a long time like that.

Just stay unlocked on the pavment.

Off-road you will have some pretty serious jerking in the steering wheel, and it will be pulling to the center all the time. You will need to keep your eyes open, and your hands tight.

The only problem? He has AWD at the moment. Totally cool if he already had the locking hubs...

[bpassmore]

Yes, it would require getting those hubs asap.

[alkaline747trio]

Wow, so all the people with auto-lockers in the front of their part time rigs blow out their front ends every time they engage 4wd??

And...DUHHHH....of course I'm getting locking hubs.....again, DUHHHH....I know I can run with them un-locked on the road all I want. The question is, what does it drive like not unlocked? I'm assuming it would be similar to a part-time rig with lunch box lockers in both ends in 4wd, but how does the open center change things?

[bpassmore]

"What does it drive like"
On road - a little noisy, but not really anything noticeable. - (with unlocked hubs.....)

Off road, a little jerky, (kinda like your response above) and it will pull to the center pretty hard at times.

[NaterGator]

Have you driven an e-locker 80? Locking the front and trying to turn on pavement is what it's going to feel like if you ever happen to have your front lock. Except that you'll be at speed, probably in a turn when it happens.

There is alot of weight up front, and at speed in a turn something is going to give. IDK if it's gonna be traction or some part of the front end, but IMO you can't expect to drive a full-time 4wd with a front autolocker on the road w/o locking front hubs.

[cool breeze]

Originally Posted by bpassmore

Off road, a little jerky, (kinda like your response above) and it will pull to the center pretty hard at times.

[alkaline747trio]

I tried to express my awareness to the common knowledge of an auto locker in a full-time 4wd vehicle. I even expressed that it was a waste of time to respond with that type of information.

Yet all the posts were the same redundant posts that get thrown up when a noob asks questons like this. I am not a noob...please don't treat me as such. And don't ignore the question asked. Basically, unless you have driven with an auto locker in the front and rear of a full-time 4wd vehicle you couldn't possibly answer my question.

NaterGator...its not quite the same. An e-locked front end is a spooled front end. The autolocker on the other hand, can release each side to spin at different RPMs but they both must be faster than the pinion. The open center diff allows both axles to spin freely of eachother, but one must be atleast the speed of the input shaft RPM.

Also, bpassmore...on-road, with un-locked hubs, and the front drive-shaft disengaged, there would be no noise and one wouldn't be able to tell if there was even a locker in the front end at all....would be the same as a 2wd vehicle.

What I would like to know is this: on-road, with locked hubs (drive flanges still installed) and an open center diff (not 2wd or true 4wd) what is my rig going to drive like?

[bpassmore]

"What I would like to know is this: on-road, with locked hubs (drive flanges still installed) and an open center diff (not 2wd or true 4wd) what is my rig going to drive like?"

It will drive normal while you go straight, then when you start making turns, your will feel binding and friction.

Eventually you will get a stress relief, either from a wheel spinning free, or from your birfs, or drive shaft or tcase gears popping.

i did this on a 1974 Bronco. I had a dana 44 front end, and after about 2 miles, the steering was so hard to turn the i had to start backing up.
I got to a point where I could put the Dana 20 tcase back in neutral, albeit with some great force.

I later had to drive in 4wd again because of a tcase lockup (i can only assume from the damage created in that test), and this time i popped a front ujoint (no birfs).

Short answer, it will get real hard to steer, it will get really bound up in the drive train, and you will break something. It wont take long.

[alkaline747trio]

Why did the locker not disengage? Is the D20 a gear type center diff? Or is it not just a standard chain driven part-time unit?

[bpassmore]

gear type. part time unit. I was testing basicaly this same scenario, just in different rig.

[bpassmore]

the lunchbox will NOT unlock under bind. i had to backup about a mile before I could put the tcase back in neutral.
the front axle popped pretty loud on that one too.

I strained some parts pretty good, as evidence by the later broken ujoint in the D44, and the quirky D20 tcase post bind.

[NaterGator]

Originally Posted by alkaline747trio

NaterGator...its not quite the same. An e-locked front end is a spooled front end. The autolocker on the other hand, can release each side to spin at different RPMs but they both must be faster than the pinion. The open center diff allows both axles to spin freely of eachother, but one must be atleast the speed of the input shaft RPM.

Well, it sorta is, sorta isn't. From my understanding an autolocker will lock once positive torque is applied from the pinion and there is a difference in angular velocity between the L and R shafts.

To get to the root of your question, the arc taken by the front axle is negligibly different from that of the rear axle, especially compared to the difference of the inside wheel to the outside. The center diff is going to be the least of your problems....

There is a differential equation (no pun intended) that describes the motion of both, but suffice it to say that the L&R front wheel speeds differ much more than the front/rear pinion speed.

[-Spike-]

You obviously don't understand how an auto-locker works. Let me clue you in: it LOCKS.

Go break something and get back to us.

-Spike

[alkaline747trio]

Originally Posted by -Spike-

You obviously don't understand how an auto-locker works. Let me clue you in: it LOCKS.

Go break something and get back to us.

-Spike

I thought it UNLOCKED when a tire wanted to travel faster than the pinion. Is the outside tire not going to do this? Maybe the aussie works too well in the rear for me to really understand this, but I never push or drag a rear tire....why does this change so much in the front? What happens in the front that doesn't let an auto locker work like it does in the rear?

[NaterGator]

Originally Posted by alkaline747trio

I thought it UNLOCKED when a tire wanted to travel faster than the pinion. Is the outside tire not going to do this? Maybe the aussie works too well in the rear for me to really understand this, but I never push or drag a rear tire....why does this change so much in the front? What happens in the front that doesn't let an auto locker work like it does in the rear?

No. The outside tire sets the nominal torque baseline. The inside tire receives proportionally more torque, so the bias is positive and towards the inside tire. The diff sees this bias and locks the front end up whenever the engine is putting power through the pinion. It's the reason that high performance cars with open diffs tend to spin the inside wheel when cornering under acceleration.

The angular velocity differential in the rear end during a turn is much less than in the front. Also, there is more weight up front, the front wheels are tasked with getting traction to impart the lateral motion on the vehicle, etc.

['74 UA FJ]

Let me throw in a couple of cents.

I think it's doable as long as you are pretty careful around turns, i.e. not using the throttle while turning. I think that the slippage in the center differential will afford you enough error to not keep the front locker locked up all the time. My experience with Aussie lockers front and rear in 4wd tells me that when under load, all four will be locked up, and when not under load, both ends are free to ratchet.

Just throw it in there and check it out. It's either drivable (score), or it's not and you buy hubs...

[NaterGator]

Originally Posted by '74 UA FJ

Just throw it in there and check it out. It's either drivable (score), or it's not and you buy hubs...

Is this truck a DD, or how much time does it spend on pavement? Because the first time you are going around a decent turn at decent speed and forget and even slightly get on the throttle, you're probably (eventually) going to have a major problem... not just "hmm I need to get hubs now."

['74 UA FJ]

Originally Posted by NaterGator

Is this truck a DD, or how much time does it spend on pavement? Because the first time you are going around a decent turn at decent speed and forget and even slightly get on the throttle, you're probably (eventually) going to have a major problem... not just "hmm I need to get hubs now."

Isn't that the dude with like 38s or something? I didn't think it was a daily driver.

[NaterGator]

Originally Posted by '74 UA FJ

Isn't that the dude with like 38s or something? I didn't think it was a daily driver.

I think it's pretty darn big, but I'm not sure he doesn't use it to run to the hardware store, etc. If it sees pavement time at all, it won't work IMO. How could you possibly turn left from a stop light? You'd have to be far enough back that you could make a run up to the light and then coast through it. Same thing with stop signs, etc.

Huge pain, wont work, wait to you get hubs. (if driving this thing on pavement)

[/thread]

['74 UA FJ]

Originally Posted by NaterGator

I think it's pretty darn big, but I'm not sure he doesn't use it to run to the hardware store, etc. If it sees pavement time at all, it won't work IMO. How could you possibly turn left from a stop light? You'd have to be far enough back that you could make a run up to the light and then coast through it. Same thing with stop signs, etc.

Huge pain, wont work, wait to you get hubs. (if driving this thing on pavement)

[/thread]

See, I'm just not sure. It might have just enough slip in the center to make it work. Albeit not well, but drivable. I know for a fact that you can drive a 40 on the road with no rear driveshaft and a locked up front. And some other weird combinations as well.

Trio, just do it and post up your experience. Uh, do it on a secluded road.

[NaterGator]

Originally Posted by '74 UA FJ

See, I'm just not sure. It might have just enough slip in the center to make it work. Albeit not well, but drivable. I know for a fact that you can drive a 40 on the road with no rear driveshaft and a locked up front. And some other weird combinations as well.

Trio, just do it and post up your experience. Uh, do it on a secluded road.

It's not going to make a bit of difference about the center diff... the diff lock will keep the axle shafts at the same angular velocity, The ω of the pinion isn't going to be greatly affected, in fact it will be irrelevant compared to the windup that will occur from the δω in the axle shafts.

['74 UA FJ]

Originally Posted by NaterGator

It's not going to make a bit of difference about the center diff... the diff lock will keep the axle shafts at the same angular velocity, The ω of the pinion isn't going to be greatly affected, in fact it will be irrelevant compared to the windup that will occur from the δω in the axle shafts.

And the question there is whether or not the auto locker will ratchet to allow the δω. I am just curious. I don't have a dog in the hunt, that's why I bought a lc with factory lockers...

[NaterGator]

The point of a locker is to engage until the torque difference between the two output shafts is zero, which only happens while coasting and when they are unloaded. Once it locks in a turn, it's not going to unlock until you can straighten out or come to a stop and back up. It'd be a mess.