Lockers in the Rear or in the Front (1 Viewer)

[anajjar]

Hey guys

I'm about to put ARB lockers in my 2000 Lexus Lx470 and i was wondering if to start in the rear or in the front?

Everyone that i've asked tell me to go with the rear one first but i believe that for our trucks the front one will come more handy more often.

What are your thoughts?

 

[Wilsil]

That is a hard question.
I have an E-locker in the front.
Why? Because the front diff was out for seal replacement so cheaper to do it at the same time.
It will also strenghten the front diff which is the weakest point.

 

[anajjar]

All the videos I see, I'm always seeing our front wheels in the air... More than the rear. Isn't it logical to go with the front in our case?

But then again... Why do all the cars that come with lockers, stock, have them on the back. Like the FJ

 

[spressomon]

Generally speaking I use my front locker quite a bit more than my rear locker on the 100. But it depends on the terrain. For more technical rock ledge/wall climbing definitely the front goes on first.

And the reason: If you look at any 100/200 photos when climbing you will notice the front suspension is unloaded due to how the torque is induced to the IFS suspension. Thereby shifting the weight center rearward. And the IFS's limited articulation sees more frequent use of the front locker too.

Whereas my 80-Series wheeling pals don't get this torque induced front suspension lift and rarely rely upon their front locker.

And then there's the biggest reason, IMO, of all to do the front before the rear if budget constraints don't allow for both: Taking care of the relatively weak/flexy OEM front diff carrier with a significantly stronger/more rigid ARB locker & carrier assembly.

 

[Chris Sandstorm FJ]

I have also heard the first locker might be best up front for similar reasons to Spresso's great explanation.

It has also been explained to me that the rear lock can sometimes shift you upfront to where you might not want to be, where as the front most often will grab and pull you through your desired line.

With that said, I had a rear e-locker with my FJC coupled with Atrac. That is a really powerful combo. One that you could easily do the Rubicon with.

For me it just depends on which diff needs work first, then that is the one I will most likely drop a locker into first.

So far, I have not seen a situation that the Atrac could not get me through, as far as ledges and what not are concerned.

 

[Layonnn]

Id rather have the rear. Spresso haven't you said before that one of the reasons you use your front more often is because ARBs are far quicker to engage and disengage compared to OEM e-lockers? Do you think that would be the case if you had ARBs front and rear?

The place you need lockers most is climbing. When the vehicle is climbing the weight is shifted rearward thereby giving the rear tires more traction than the fronts which have less weight on them, and less traction. Not to mention the fact that if you have the front locked on an IFS you sure as heck have to be careful with the throttle and the steering wheel. You will have limited steering with the front end locked.

There is a reason Toyota dropped the front locker when they started making the 100 series and why they don't offer a front locker on any IFS rig (at least in the US) that they make. Its more beneficial in the rear and less chance of breaking CVs.

 

[spressomon]

Its true the ARB locks/unlocks quicker than the OEM e-locker. Having said that due to the design of same the 80-Series front e-locker locks/unlocks quicker (typically) than the rear...I've never had the benefit of testing a rear ARB locker to compare against the rear OEM e-locker.

Nope...played around with this for the past 6-years on this truck and generally the front gets locked first and sometimes only for most climbs not requiring both.

Tight turns and other mitigating circumstances on each trail effect locker usage too. And the type of terrain you travel across will also make a difference. For instance in muddy conditions where I need some speed to get through long stretches of flooded and/or muddy trail I generally rely only on the rear locker for less negative steering effect. Or if I'm on a slippery off-camber...

Tight twisty east coast type trails will generally favor the rear locker being activated first...but out here its a little different story. On our recent foray on Poison Spider/Golden Spike/Goldbar there were a few steps I had to be triple locked...whereas Ali and John in their 80's would mostly be only CDL locked and maybe the rear locked for big walls with polished and/or sandy surfaces...but other than that I never had just the rear locker engaged. But there were numerous times I had just the front locker engaged to get through a section.

And then...with the weight transfer/IFS unloading there is more available traction on the rear anyway...

And aside from all that its just plain russian roulette not doing the ARB up front on the 100's if you have to choose between either especially.

Although no one probably knows outside of the center Toyota thinktank I surmise the absence of the front locker had to do more with their target demographic for IFS platforms and general liability issues with 99% of buyers not having a clue how/when to use/not use the front locker.

As with many other things YMMV.

 

[rusty_tlc]

I'd do the front first just for the peace of mind.

As far as which is better done first from a strictly performance point of view I'd go rear first. I live just a few miles from Spresso but I wheel our 100 completely differently than he does. I agree with his arguments for front first based on what he does.

In most cases we are using the 100 to travel relatively mild gravel roads with an occasional tough spot, typically a washout. Or using the truck to get down to the shore line at a lake or on a fairly level snow packed trail, pulling the trailer through a section of loose sand or gravel etc. All stuff where a rear locker has the advantage. The fact is my front locker hasn't worked in a couple of years due to an installation induced air leak and I haven't missed it at all.


So once again "Best" is highly subjective.

If you don't have any experience with using lockers take time to read about how and when* to use them. Think about what you plan to do with your truck and where you want to go.


* There are situations when using a locker will cause you more trouble than being open diff. For instance off camber in loose soil, mud or snow. When an axle locks both wheels can spin, sometimes this will cause one or both axles to slide down hill. If only one wheel spins the other acts as an "anchor" to hold the truck.

 

[anajjar]

Guys

Thanks a lot for your response. All seem very professional and valid answers.

The truth is I don't have lots of experience with this manner so I think going with the rear would be a better/safer way to go. Either way eventually I'm doing both.

Another question...:whoops:

When you guys did your lockers... Did you guys do your gears also?

 

[hoser]

Yes, gears at the same time as locker. But you probably then want to do both front and rear at the same time. Unless you are planning on running around in RWD for the time being.

Wilsil, how is that Eaton/Harrop front locker working out for you? How quick is the engagement?

If I was only getting one (and probably 2), I would give that locker consideration as it is simpler than the ARB's. It costs more but maybe not much more if you compare it to ARB+compressor+extra labor involved to install.

ACC Toyota is thinking about importing some of Eaton/Harrop lockers.

 

[anajjar]

Any suggestion on the gears?

 

[Layonnn]

Any suggestion on the gears?

If you are planning to stay near stock sized tires, gears are not necessary and will make your mileage worse.

If you are going to run larger tires and add some bumpers, then gears are more of a "want" item.

4.88s are really the only good option as you have 4.3s in there right now. Going to 4.56s is such a small change that i don't feel its worth the money.

But yes, gears at the same time make sense as everything has to be taken apart anyways. There is usually very little difference in labor charges when you add in gears to a locker install.
If you are only doing one end at a time that presents a problem though. You cannot only re-gear one axle at a time. Well you can but you'd have to remove your front drive shaft.

 

[BMX and CRUISERS]

I would wait...save...then do it all. ARB's and gears.

 

[anajjar]

I'm running 305's, lift, and just purchased bumper, lights, winch, air compressor, rear locker

haha and seeing how the winds are blowing I think i'm buying front lockers as well.

How bad is it if i do everything (just the rear locker) and no gears whatsoever?

 

[rusty_tlc]

Yes, gears at the same time as locker. But you probably then want to do both front and rear at the same time. Unless you are planning on running around in RWD for the time being.

Wilsil, how is that Eaton/Harrop front locker working out for you? How quick is the engagement?

If I was only getting one (and probably 2), I would give that locker consideration as it is simpler than the ARB's. It costs more but maybe not much more if you compare it to ARB+compressor+extra labor involved to install.

ACC Toyota is thinking about importing some of Eaton/Harrop lockers.

I'd do the Eaton lockers in a heart beat if they were available, I just installed one in the rear diff of my son's Jeep and they are beefy and engage really fast. Install was pretty easy but we didn't change gears on his truck.

 

[KlausVanWinkle]

The place you need lockers most is climbing. When the vehicle is climbing the weight is shifted rearward thereby giving the rear tires more traction than the fronts which have less weight on them, and less traction.

Wouldn't that mean that lockers in the front would be more useful? If most of the weight and traction are in the rear, then the rear tires would be less likely to slip and if they did ATRAC would catch them.

If the front doesn't have traction or weight, it's more likely to slip or left a wheel. And if they spin and suddenly get traction, they're more likely to bust the front diff.

I don't have lockers, so this is completely theoretical.

 

[hoser]

I'd do the Eaton lockers in a heart beat if they were available, I just installed one in the rear diff of my son's Jeep and they are beefy and engage really fast. Install was pretty easy but we didn't change gears on his truck.

Thanks, perhaps next time, I'll go that route.

 

[dean58]

Got the eaton/harrop in the front of my cruiser and mate has the Arb. we both agree that the eaton/harrop seems to work better after some time off road. One of the best situation we have found is on a track we drive quite often where you drive down into the river bed with the locker on as there are huge wash aways and a lip to get in. ( can't get in without it) but once in need to disengage to make the turn to drive down strem for the exit of the track. He has got caught about 3 times now where the wheels are bound up from the lip that the locker wont disengage and has needed me to gently pull the front around about half a meter so the wheels are not binding then the locker releases and he can drive out. Where as in mine if the switch is on its on and as soon as its off the locker is off. Do t know exactly the reasons but just seems that why and has been a few times. On the one track especially quite a few cars get caught in the same spot with the locker not disengaging. Just my two sense, sorry slightly off topic

 

[Layonnn]

Wouldn't that mean that lockers in the front would be more useful? If most of the weight and traction are in the rear, then the rear tires would be less likely to slip and if they did ATRAC would catch them.

If the front doesn't have traction or weight, it's more likely to slip or left a wheel. And if they spin and suddenly get traction, they're more likely to bust the front diff.

I don't have lockers, so this is completely theoretical.

The problem is that even if the front is locked, with so little weight (compared to the rear) it won't pull near as hard as the rear could push.

A spinning wheel all the sudden gaining traction is MORE of a problem if the axle IS locked. If the axle is locked and you are spinning the tires trying to gain traction and then all the sudden one side does, that puts a lot of strain on the axles and diff. If the axle was unlocked the tire that gains traction would stop but the other tire would spin, not creating the same type of stress on the diff and axles.

 

[sonk76]

A spinning wheel all the sudden gaining traction is MORE of a problem if the axle IS locked. If the axle is locked and you are spinning the tires trying to gain traction and then all the sudden one side does, that puts a lot of strain on the axles and diff. If the axle was unlocked the tire that gains traction would stop but the other tire would spin, not creating the same type of stress on the diff and axles.

I guess above would be true in the scenario that BOTH of the tires were spinning loose (e.g., both in the air) and then one came crashing down, while the other remained air-borne. In that scenario, I could see how open diff might do a bit better.

In a more typical scenario, where only on of the front tires is in the air and spinning freely, while the other is more or less stationary, when the spinning tire eventually hits the ground it causes all the load to be instantly off-loaded into the rest of the system causing big shock load (i.e., the stopped wheel will need to almost instantly accelerate to some relatively high speed to catch up with all the momentum in the spinning wheel.)

If the axle were locked, the other side would have already been spinning, and there is nothing that requires instantaneous acceleration from zero to some high rate of spinning.

Just my misguided two cents (also, empirical personal experience--completely non-scientific: open front diff ==> blown pinion gear, locked front diff ==> no issues/damage since)