best locker?
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Joined: Dec 2008
Posts: 1,136
Likes: 4
From: Huntington Beach, CA
An Aussie is a great choice for a front JK axle. The possibility of pin failure that was previously mentioned should be very minimal in a front axle.
As for road manners, my comments were directed at rear axle applications. An Aussie should be totally invisible in the front axle of a JK in 2WD. I've heard some people say that they can feel it but that has not been my experience. We've seen this type of locker in YJs and TJs (front axle) for years with no handling issues.
As for auto lockers in rear axle applications, check below. This is somehing I wrote years ago that still applies today with the JK.
Detroit vehicle set up
If you go with an auto locker in the rear axle (Detroit or Aussie) you'll want to check your tires for their circumference. An auto locker is always locked until the outside axle must unlock and overspeed to navigate a corner. After the corner, the outside axle will again lock when equal axle speed has occurred. If your tires are of unequal circumference, the axle will lock and unlock at inappropriate times causing handling issues. Even a tire with low air pressure can change the circumference and the larger tire will cause the locker to unlock even on a straight road.
To check your tires, air all 4 tires up to 25 PSI. Use a good gauge not some POS pencil style. Then using chalk, draw a down the sidewall of the tire and onto the pavement. Do this with all 4 tires. Next you roll the rig until the side wall mark once again contacts the ground and you make another mark on the pavement. Now you measure the distance between the marks of each tire. You now put the 2 tires with the closest measurement on the rear axle.
TJs with long arm kits are notorious for their lack of precision in suspension set up. For example, if a bolt won't go in the long arm because of improper alignment what happens? The installer loosens or tightens the heim until the bolt will pass through. Are all the arms the same length now? With an open diff or a selectable, poor axle alignment is masked. An auto locker will show these faults. Additionally, TJs aren't known for precise bracket locations and most long arm kits require you to measure up for placement.
To get the best performance from an auto locker, you should get a GOOD 4 wheel alignment. It's almost never done and it makes a huge difference. This alignment will get your long arms set to proper length, and make sure your rig is tracking true. There are even ways to adjust stock short arms that will help. Do it.
As for road manners, my comments were directed at rear axle applications. An Aussie should be totally invisible in the front axle of a JK in 2WD. I've heard some people say that they can feel it but that has not been my experience. We've seen this type of locker in YJs and TJs (front axle) for years with no handling issues.
As for auto lockers in rear axle applications, check below. This is somehing I wrote years ago that still applies today with the JK.
Detroit vehicle set up
If you go with an auto locker in the rear axle (Detroit or Aussie) you'll want to check your tires for their circumference. An auto locker is always locked until the outside axle must unlock and overspeed to navigate a corner. After the corner, the outside axle will again lock when equal axle speed has occurred. If your tires are of unequal circumference, the axle will lock and unlock at inappropriate times causing handling issues. Even a tire with low air pressure can change the circumference and the larger tire will cause the locker to unlock even on a straight road.
To check your tires, air all 4 tires up to 25 PSI. Use a good gauge not some POS pencil style. Then using chalk, draw a down the sidewall of the tire and onto the pavement. Do this with all 4 tires. Next you roll the rig until the side wall mark once again contacts the ground and you make another mark on the pavement. Now you measure the distance between the marks of each tire. You now put the 2 tires with the closest measurement on the rear axle.
TJs with long arm kits are notorious for their lack of precision in suspension set up. For example, if a bolt won't go in the long arm because of improper alignment what happens? The installer loosens or tightens the heim until the bolt will pass through. Are all the arms the same length now? With an open diff or a selectable, poor axle alignment is masked. An auto locker will show these faults. Additionally, TJs aren't known for precise bracket locations and most long arm kits require you to measure up for placement.
To get the best performance from an auto locker, you should get a GOOD 4 wheel alignment. It's almost never done and it makes a huge difference. This alignment will get your long arms set to proper length, and make sure your rig is tracking true. There are even ways to adjust stock short arms that will help. Do it.
Last edited by Dynatrac; Jul 29, 2010 at 08:42 AM.
JK Jedi Master
Joined: Jan 2008
Posts: 11,463
Likes: 165
From: Austin <--> Colorado Springs
Locker Warranties
Would any locker be better than any other in regards to the mfg's warranty? The only one I found so far is the Eaton ELocker, which states that it is void if you go above stock tire size.
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Joined: Dec 2008
Posts: 1,136
Likes: 4
From: Huntington Beach, CA
The Eaton ELocker had a bad warranty for the earlier models. I don't know if I've seen any warranty info regarding the new 'Hardcore' Dana 30 and 35. According to my sources at Eaton, they haven't had a 30 or 35 come back for warranty--ever. Given the testing info I received from their engineering staff during Easter Safari, I have no problem believing they haven't had a claim. Their testing had them breaking HP 30 3.73 ring gears and 4340 shafts and still not having any locker failures. Warranty or not, the Eaton would be my choice for a D30 selectable.
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Joined: Dec 2008
Posts: 1,136
Likes: 4
From: Huntington Beach, CA
This makes sense because if the locker senses any resistance it will lock. A hard turn would amplify any binding. I have had Detroits in the front axles of my Jeeps for nearly 20 years now and I can't think of a single time that I could feel any locker bind in 2WD. I've had a selectable for a long time too but I actually prefer a Detroit. I do a lot of very tight woods wheeling and use my twin stick very frequently. Front digs help whether you have a front selectable or not. It's nice only having to do one motion (the stick) instead of 2 (stick and locker).
JK Super Freak
Joined: Mar 2008
Posts: 1,439
Likes: 1
From: Flyover Country
My gear man did my Dana 30 front Aussie Locker installation yesterday morning. Clearances were right within spec. Having seen how easy this went together, I probably could have tackled it with WOL's old write-up. Anyway...
Drove into a grassy/weedy empty lot near the house, put it in 4HI, made a few slow turns near full lock on the turf ... front end shuddered a little, locked up tight, and the JK tilled a nice 12.50" wide abrasion in the crabgrass as one tire turned at a different speed than the other.
And just as Dynatrac suggested: this locker is invisible in everyday driving scenarios. Thanks for the advice (especially on a product you don't sell!) and thanks (again!!!) to Northridge for yet another quality mod!
David = crack dealer
Drove into a grassy/weedy empty lot near the house, put it in 4HI, made a few slow turns near full lock on the turf ... front end shuddered a little, locked up tight, and the JK tilled a nice 12.50" wide abrasion in the crabgrass as one tire turned at a different speed than the other.
And just as Dynatrac suggested: this locker is invisible in everyday driving scenarios. Thanks for the advice (especially on a product you don't sell!) and thanks (again!!!) to Northridge for yet another quality mod!
David = crack dealer
JK Enthusiast
Joined: Jan 2008
Posts: 180
Likes: 0
From: Danville, CA
As others have stated, 'best' is subjective, but in catagories there are brands and designs that are better than others.
Auto locker- This is a locking differential that is always locked unless an outside tire needs to overspeed to navigate a corner. In this situation the outside axle is unlocked and the rig is driven by the inside axle. Tire circumference and suspension set up are crucial to good road manners in a rear axle. I can give specifics on how to improve road manners if needed.
Lockers in this catagory include: Detroit Locker, Grizzly Locker (Detroit Locker near copy made overseas by Yukon/Randy's R&P), Lock Right, Power Trax No-Slip, E-Z Locker, Aussie Locker and Yukon/Randy's Spartan Locker. The Detroit and Grizzly are full case lockers and the rest are 'lunch box' lockers. 'Lunch box' refers to the box shape that the lockers are sold in. Auto Lockers are invisible in front axle applications in 2 WD. In 4WD they can tax your steering but are a very nice addition.
Unlike a full case auto locker, the lunch box locker (except a Power Trax No-Slip) will wear out over time. The internal teeth of the locker will round and eventually cause failure. The lunch box style locker is also noisier than a Detroit Locker (but similar to a Grizzly) and is much more prone to failure. A lunch box locker retains the factory case and doesn't require a professional installation. The factory case is a weak spot (as is the cross pin) and failures are fairly common. For this reason I don't usually recommend Lunch box lockers for a rear application unless they are a temporary addition.
The Detroit Locker can be damaged if you break an axle shaft. For some people it happens with the first broken shaft and for others they might break a dozen and never see any damage. Use good DOMESTIC 4340 axle shafts for best results.
In the Auto locker catagory the Detroit Locker, Aussie and Lock Rights are your best options.
Selectable Lockers- This is a differential that can changed be from open (or limited slip in the case of the Ected) to fully locked (or semi locked- also the Ected) by the operator from the drivers seat. Actuation can be achieved by 12v power, air or cable. These products have superior road manners when compared to an auto locker.
Lockers in this catagory include, ARB, Auburn Ected, Eaton ELocker, OX locker and Zip Locker (a overseas copy of an old design ARB made by Yukon/Randy's R&P).
ARB is still the standard. While they are more prone to failure due to poor installation, ARBs remain on the top of the heap. They lock and unlock very quickly and are very strong.
The Eaton ELocker is right up there with ARB with their Dana 30 (and 35) model but the ELocker has an edge due to its 12V actuation. Testing has shown the ELocker to be equal to ARB in strength and ease of actuation. The other ELocker models have an inferior 2 pinion design that is much weaker than their comparable ARB. Their actuation method, although also 12V, is different than the Dana 30 version and is prone to failure.
The OX locker is very strong but still suffers from a poor actuation method. The cable actuation can be very good or very bad depending on the user. OX also provides an air or electric actuation method but they aren't yet a great option. Actuation is also much more cumbersome than the competitors. While usually fairly easy to lock, sometimes unlocking them can be a real chore.
The Auburn Ected looks great on paper but the actual function is poor when compared to the others. This unit is based on a clutch driven limited slip design and doesn't truly 'lock'. When 'locked', extra pressure is given to the clutches and it will act locked unless there is enough engine torque and traction to overcome the clutch pressure. Additionally, over time, the clutches will wear and lock up will be even less effective. If that wasn't bad enough, the internal side gear design has very little axle spline engagement in the LSD mode and axle shafts have been getting the splines stripped. Auburn is working on a new Ected model that is said to address these issues.
The Zip Locker is a copy of an old ARB design and is a poor substitute for the new ARB. Cost is very close to the ARB but there isn't any benefit.
The best part of a selectable locker is also the worst part- YOU must make the choice. If you forget to make the choice it can sometimes lead to a bad situation. A selectable locker up front will be harder to steer (while locked) than an auto locker. Steering box and pump upgrades should be considered for best operation with this product.
In the selectable locker catagory the ARB and the Dana 30 ELockers are the best options.
Spools were mentioned also as an option to be considered.
Spools are a solid lock between the R&P and the axle shaft. The function can be obtained by installing a differential replacement- a spool, by installing a locking block inside the factory case (called a mini spool) and by welding up the internals of the factory differential. All of these methods work exactly alike but an actual spool is stronger and not prone to failure.
While a spool does provide very consistant, reliable traction, it also places a huge amount of additional stress on your axle shafts during street driving and causes excessive rear tire wear. Off road, a rear spool will greatly increase your turning radius.
For some a spool could be a good option but for 90% of the wheeling world it's a bad choice.
Auto locker- This is a locking differential that is always locked unless an outside tire needs to overspeed to navigate a corner. In this situation the outside axle is unlocked and the rig is driven by the inside axle. Tire circumference and suspension set up are crucial to good road manners in a rear axle. I can give specifics on how to improve road manners if needed.
Lockers in this catagory include: Detroit Locker, Grizzly Locker (Detroit Locker near copy made overseas by Yukon/Randy's R&P), Lock Right, Power Trax No-Slip, E-Z Locker, Aussie Locker and Yukon/Randy's Spartan Locker. The Detroit and Grizzly are full case lockers and the rest are 'lunch box' lockers. 'Lunch box' refers to the box shape that the lockers are sold in. Auto Lockers are invisible in front axle applications in 2 WD. In 4WD they can tax your steering but are a very nice addition.
Unlike a full case auto locker, the lunch box locker (except a Power Trax No-Slip) will wear out over time. The internal teeth of the locker will round and eventually cause failure. The lunch box style locker is also noisier than a Detroit Locker (but similar to a Grizzly) and is much more prone to failure. A lunch box locker retains the factory case and doesn't require a professional installation. The factory case is a weak spot (as is the cross pin) and failures are fairly common. For this reason I don't usually recommend Lunch box lockers for a rear application unless they are a temporary addition.
The Detroit Locker can be damaged if you break an axle shaft. For some people it happens with the first broken shaft and for others they might break a dozen and never see any damage. Use good DOMESTIC 4340 axle shafts for best results.
In the Auto locker catagory the Detroit Locker, Aussie and Lock Rights are your best options.
Selectable Lockers- This is a differential that can changed be from open (or limited slip in the case of the Ected) to fully locked (or semi locked- also the Ected) by the operator from the drivers seat. Actuation can be achieved by 12v power, air or cable. These products have superior road manners when compared to an auto locker.
Lockers in this catagory include, ARB, Auburn Ected, Eaton ELocker, OX locker and Zip Locker (a overseas copy of an old design ARB made by Yukon/Randy's R&P).
ARB is still the standard. While they are more prone to failure due to poor installation, ARBs remain on the top of the heap. They lock and unlock very quickly and are very strong.
The Eaton ELocker is right up there with ARB with their Dana 30 (and 35) model but the ELocker has an edge due to its 12V actuation. Testing has shown the ELocker to be equal to ARB in strength and ease of actuation. The other ELocker models have an inferior 2 pinion design that is much weaker than their comparable ARB. Their actuation method, although also 12V, is different than the Dana 30 version and is prone to failure.
The OX locker is very strong but still suffers from a poor actuation method. The cable actuation can be very good or very bad depending on the user. OX also provides an air or electric actuation method but they aren't yet a great option. Actuation is also much more cumbersome than the competitors. While usually fairly easy to lock, sometimes unlocking them can be a real chore.
The Auburn Ected looks great on paper but the actual function is poor when compared to the others. This unit is based on a clutch driven limited slip design and doesn't truly 'lock'. When 'locked', extra pressure is given to the clutches and it will act locked unless there is enough engine torque and traction to overcome the clutch pressure. Additionally, over time, the clutches will wear and lock up will be even less effective. If that wasn't bad enough, the internal side gear design has very little axle spline engagement in the LSD mode and axle shafts have been getting the splines stripped. Auburn is working on a new Ected model that is said to address these issues.
The Zip Locker is a copy of an old ARB design and is a poor substitute for the new ARB. Cost is very close to the ARB but there isn't any benefit.
The best part of a selectable locker is also the worst part- YOU must make the choice. If you forget to make the choice it can sometimes lead to a bad situation. A selectable locker up front will be harder to steer (while locked) than an auto locker. Steering box and pump upgrades should be considered for best operation with this product.
In the selectable locker catagory the ARB and the Dana 30 ELockers are the best options.
Spools were mentioned also as an option to be considered.
Spools are a solid lock between the R&P and the axle shaft. The function can be obtained by installing a differential replacement- a spool, by installing a locking block inside the factory case (called a mini spool) and by welding up the internals of the factory differential. All of these methods work exactly alike but an actual spool is stronger and not prone to failure.
While a spool does provide very consistant, reliable traction, it also places a huge amount of additional stress on your axle shafts during street driving and causes excessive rear tire wear. Off road, a rear spool will greatly increase your turning radius.
For some a spool could be a good option but for 90% of the wheeling world it's a bad choice.