Front or Rear locker, but not both

[jacobconroy]

This is a lot of good information and opinions. How about more details on LSDs? If I'm following this, they are more of a "soft" locker? Meaning that they will allow some difference in wheel speed...but will lock when they need to?

 

[IdaSHO]

LSD is not a locker. Its in the name.... Limited Slip
It will turn both but allow (limited) slip when both tires on the same axle are on the ground, and are turning at different rates.
But once you lift a tire, they are as useless as an open diff.

As for the topic on hand, I personally would never put a front locker on a vehicle, unless it saw lots of legit rock crawling.

A rear locker is a game changer for the vast majority of drivers, for good reason.
It is a monster improvement over open diffs or limited slips, and IMO should be on every vehicle that plans to leave the pavement.
Open when not locked, fully locked when you need it.

Open diff when not locked is super safe for DD and highway travel. If the rear looses traction on ice/snow/washboard, whatever, you will simply spin and loose speed.
Locked, or even with a good LSD, the rear end will walk sideways on you, and it is quite easy in slick situations for an inexperienced driver to swap ends.

 

[jacobconroy]

LSD is not a locker. Its in the name.... Limited Slip
It will turn both but allow (limited) slip when both tires on the same axle are on the ground, and are turning at different rates.
But once you lift a tire, they are as useless as an open diff.

As for the topic on hand, I personally would never put a front locker on a vehicle, unless it saw lots of legit rock crawling.

A rear locker is a game changer for the vast majority of drivers, for good reason.
It is a monster improvement over open diffs or limited slips, and IMO should be on every vehicle that plans to leave the pavement.
Open when not locked, fully locked when you need it.

Open diff when not locked is super safe for DD and highway travel. If the rear looses traction on ice/snow/washboard, whatever, you will simply spin and loose speed.
Locked, or even with a good LSD, the rear end will walk sideways on you, and it is quite easy in slick situations for an inexperienced driver to swap ends.

Cool. Now I'm leaning towards a good-old manual locker on the rear only. What are the thoughts on mechanical vs air-operated?

 

[IdaSHO]

I go air or electric, but prefer electric from an install and use perspective.

In most cases, your application is the deciding factor.
Not every option is available in every application.

 

[Saint Nick]

Even with hub locks I'd only run a selectable locker in front, e.g. an Air Locker, or maybe a LSD. Having a locked front axle that you can't open makes mild trails (those where 4wd is useful but not so hard as you to need two lockers) unnecessarily difficult. You're fighting the locker all the time trying to steer. When I had dual lockers I used the front maybe a handful of trails and those you usually have to seek out. Even on the Rubicon I only maybe used it half a dozen times. The locker in the rear gains you the majority of utility. I'd spend money on a winch before a front locker personally.

I can understand what you are saying and see exactly where you're coming from, but unless my understanding of the following is wrong (which it could well be ?) using an Aussie locker should give no steering problems (taken from the Aussie locker site).

If only installing one locker should I install in the front or rear?

This is dependent on your personal preference, the type of vehicle, existing diff types, and how you intend to use the vehicle.
We "Do Not" recommend the installation of a locker in the front of a vehicle that will be driven on icy highways in 4WD without manual hubs.
If a vehicle has an IFS (Independent Front Suspension) system then the front installation will result in a dramatic increase in 4WD capability. This is because all IFS vehicles have very limited suspension movement (wheel travel and articulation) resulting in easily lifted wheels and a loss of front traction. Installing a front locker will solve the deficiency.
If a vehicle has LSD (Limited Slip Differential) in the rear, then a front installation provides a significant improvement over the existing LSD and open diff set-up.
If a vehicle has constant 4WD then only a rear installation should be considered.
A front installation will usually yield the greatest improvement in off-road capability. This is due to the general requirement of increased in traction under hill climbing or rock crawling. Under full climbing conditions, due to the angle of the vehicle, the rear wheels carry a much greater weight (weight transfer) and therefore, the front carries less weight and tends to break traction very easily.
Once one front wheel starts to spin the other wheel stops turning and the whole front diff ceases to provide traction. At this point the load is transferred to the rear diff as if the vehicle was a 2WD and due to the increased load the rear wheels tend to spin and the vehicle stops. If you can stop the front wheel from spinning you have solved the traction problem. In addition to the traction performance a front installation does not introduce any changes in handling characteristics.
Will it affect my steering?
Unlike manual lockers which do not provide differential action when locked and severely hamper steering and directional maneuverability, the “Aussie Locker’s” smooth and sensitive operation allows differential action resulting in uncompromised steering, uphill or down, soft or hard surfaces. This means that you can select the best route or path, and negotiate tight steering bends easily. You can feel a mild tightening in the steering wheel which is a result of both front wheels having incredible traction, and driving more equally. There will be a self centering effect on the steering wheel in sand and off-road driving.
We "Do Not" recommend the installation of a locker in the front of a vehicle that will be driven on icy highways in 4WD without manual hubs. Driving on any slick surface requires additional attention to handling so test your Aussie Locker equipped vehicle in open areas under adverse weather conditions before driving on roads.
A front installation provides the most significant improvement over manual lockers. An “Aussie Locker” is not susceptible to drive line failures and wear present with manual lockers.

Nick

 

[PhulesAU]

I had a Detroit in the rear, and limited slip in front. Never got to play in real snow? But for trail running rock crawling and trail obsticles ( downed trees) I found very little I couldn't handle. BUTTTTTTT remember if you can't drive they won't help. One other addage?? If you can't walk in it, you can't drive in it.
If you are only doing one, put it in the rear.

 

[DaveInDenver]

Spools have their uses, and can really rock offroad. But...they can also twist or break axles - especially with big tires aired down and awesome traction.

I've never run larger than 33" tires, but once going with an Air Locker in front I never broke another CV axle in my truck. My feeling is that there are too variables to say conclusively. In the case of Toyota IFS mini trucks as I run you are much better off going slow and being in control. Wheel hop is a recipe for making CV joints in the front end grenade.

So low gears and dual lockers let me go nice and slow, walk over stuff, smooth consistent throttle, letting the suspension articulate. Even with 100:1 reduction (3.95 1st, 4.7 t-case gears, 5.29 axles) the mighty 22R-E just doesn't develop enough torque to twist axles without some difficult. It can happen but, again my experience, is you have to push it.

I now have a Tacoma with a factory electric locker. Toyota's factory lockers are full spool/open the same way as Air Lockers and Harrop/Eaton. The can break stuff but it's usually the ring & pinion that let loose first, not axle shafts. There's a large installed base, being available in the U.S. in 1996-2001 4Runners, 1995-2015 Tacoma (2016+ use a Harrop) and 80 and early 100 series Cruisers. The 80 series had factory lockers in front and rear, the 4Runner & Tacoma just rear. Not sure about the 100, I think just rear.

 

[Bayou Boy]

I really like the setup on my CJ7 of an ARB in the front and a limited slip in the rear. Easily drivable and turnable with the LS in the rear but instant traction with the flip of a switch.

 

[chasdb]

I would recommend doing the rear in your case. ARB RD93 air locker. The 2000 XJ with the 8.25 has the 29 spline axles which are the larger of the 2 offered in the XJ stock. I wouldn't put a locker into the front because you have a low pinion D30. You would benefit to swapping to a high pinion D30 Yukon Air Zip and than chromo shafts if you need more traction and strength or just wanted to build it up. Get out and have fun with a wheeling buddy and recovery gear. If you get stuck you will learn your rigs limitations and gain experience. I spent along time building mine and wish I played a lot more during the build process.

 

[Happy Joe]

And...I've never been a fan of air lockers or elockers. The reason is, that when locked, they are a spool.

Spools have their uses, and can really rock offroad. But...they can also twist or break axles - especially with big tires aired down and awesome traction.

The problem with a spool is that it won't allow the tires to rotate at different speeds. Period. Will. Not. Allow.

But when wheeling, very often, the tires NEED to rotate at different speeds. Roll one tire up and over a big rock, but not the other...with a spool you're asking for a twisted or snapped axle.

So with a "selectable locker", which is actually a "selectable spool", it's up to the driver to stay on top of it and make sure to switch it on and off as needed. For instance, switch on to get the tire up on the rock, switch off to roll down the other side.

Meh...too much micro-management for me. I've got other things to think about so there's a good chance I'll forget to flip the stupid switch at the right time, or think it's off when actually it's on...and end up snapping an axle.

I prefer a mechanical. Either Detroit Locker (ratchet) or Detroit Truetrack (clutches). And for anything other than hardcore wheeling, I wouldn't recommend a Detroit Locker. Limited slip is better for most people and most situations. For some situations...drag racing, pedal to the metal in Baja, drifting, mud bogging...gimme a spool for sure.

to each there own...
INFO; the last time that I twisted an axle was with a power lock (clutch type) limited slip... Not yet done it with ARBs, Detroits nor spools (nor even Lincoln lockers).
when you have limited traction you do not want to give any tire a chance to slip, IMO (spinning tires destroy trails and do not contribute to forward progress).
The only time that I have ever needed tires to turn at different speeds is when turning (what the off button on the front ARB is for)... (although it does require some minuscule presence of mind and effort).
"so with a "selectable locker", which is actually a "selectable spool", it's up to the driver to stay on top of it and make sure to switch it on and off as needed. " agreed; the driver should ALWAYS be in control of the vehicle... off roading is NOT a sport for the functionally unconscious. (IMO).
"Meh...too much micro-management for me. I've got other things to think about so there's a good chance I'll forget to flip the stupid switch at the right time, or think it's off when actually it's on...and end up snapping an axle." yes! this has happened but I have never snapped an axle because of it (If you are worried about snapping axles it time to up grade the weakest link ... including, possibly, the driving skills.... I ran 35s on an 4.56 geared ARB equipped narrow (weak) Dana 30 for something like 8 years on trails like Pritchet canyon in Moab and tougher, and never broke an axle (its called being careful and knowing the vehicle's limits) I did verify (breakage was expected) that small 24+ year old u-joints are not up to 14" wide Boggers without using extra care, though.

Breakage happens when the driver makes a mistake, and/or the traction allows torque to build beyond the strength of the parts. excessively large tires can break axles though that is the fault of the person that has them installed (owner error); and only means that they did not size their axles (or other broken part) correctly.

It up to each person what they prefer though, perhaps, a bit of research into the actual risks and rewards of each mod, beforehand, wouldn't hurt.

Enjoy!

 

[rnArmy]

My Jeep TJ has a Detroit locker in the rear, and an Ausie locker up front. Great for rock crawling or serious off-roading (to include snow runs). But I can feel it when the rear locker reengages after going around a curve (kind of like a little shimmy - I call it the "Detroit Shimmy" actually).

My 96 Ram 1500 4x4 has Detroit true tracks front and rear. When we get a good snow, I drive the truck around town. I feel safer in heavy snow on-road traveling with the truck. Partially because of the longer wheelbase, and partly because I know the true tracks will get me through with no handling quirks. The Jeep and truck have the exact same brand and size tire on them, so it isn't a tire thing.

My son had a beater 95 Jeep ZJ with open diffs front and rear. Our driveway had a slight slope upwards to get to the street. He was parked in the driveway backed in. I had shoveled the driveway, but the outer edge still had some compacted snow. He was half on the shoveled driveway (with traction), and half on the compacted snow (slippery), and was trying to get to the street as I was watching. It was classic open differentials at work; the tires on the compacted snow were spinning, and the other tires with traction on the driveway just sat there. If he at least had had some good LSDs in the axles (I'm a fan of the true tracks) or at least one in the rear he would have had no trouble getting out.

So if you're looking for just one axle, I would put at least a true-track in the rear.

 

[rnArmy]

And I'm of the belief that real lockers front and rear (full-time or on-demand) are actually more terrain friendly than open diffs (we're supposed to tread lightly remember?). People will get stuck more often with open diffs at the place where someone with full lockers will just keep going, and when stuck with open diffs they'll be spinning their wheels trying to keep going. The one wheel with traction will just sit there, and the wheel without traction will be spinning just digging a hole. That's how trails get tore up. Not saying you won't get stuck with full lockers, but I am saying you're less likely to do so compared to a similar vehicle with open diffs.

And off road with full lockers front and rear, you can drive more elegant - you don't have to gun it or "give it the skinny pedal!" to get through obstacles. This also helps decrease vehicle breakage by being able to drive elegant (gentle?) knowing you have traction on all four corners.

 

[bluejeep]

been there done that. TJ with a ford 8.8 in the rear and hi pinion dana 30 up front. Convinced myself that the rear would usually have more weight on it than the front and thus find traction the way it was. Wrong. Weight is not the only factor for finding traction. Flex is also involved. At any rate, after locking only the front and finding little to no performance improvement I locked the rear and found what I was looking for - fewer times pulling out the winch cable. I went with selectable OX cable lockers for both. Worked flawlessly and no 'on pavement' quirks.

 

[Bobzdar]

Yup, there's a reason rubicons have the option to lock the rear or to lock both, but not just the front - it's rare locking the front and not the rear would help much.