Lockers (Pro's and Con's of each type)

[2ndGenJonny]

Nice read, Although It takes less of a rotation to engage the Harrop.

If I were to remove the factory rear, I'd def go with another Harrop.

 

[AssBurns]

Nice read, Although It takes less of a rotation to engage the Harrop.

If I were to remove the factory rear, I'd def go with another Harrop.

Good to know about the design.

Why do you prefer the Harrop?

 

[Blender]

Nice read, Although It takes less of a rotation to engage the Harrop.

If I were to remove the factory rear, I'd def go with another Harrop.

looks like they tweaked the design compared to this old video. I'll give them credit for that.

14:17

 

[2ndGenJonny]

I like not having to deal with OBA set up. The wiring on the Harrop is super simple, it's just power.

It also seemed to be the preffered locker choice for not only ECGS, but also a local here in PHX notorious for building diffs for Toyotas (Zuk)
He swears against the ARB for the Clamshell 8" front diff.

So far it's been really awesome in the truck. It definitely engaged and disengages much faster and quieter than the OEM locker.

 

[AssBurns]

looks like they tweaked the design compared to this old video. I'll give them credit for that.

14:17

That’s the one I saw too. The new design looks much better.

I like not having to deal with OBA set up. The wiring on the Harrop is super simple, it's just power.

It also seemed to be the preffered locker choice for not only ECGS, but also a local here in PHX notorious for building diffs for Toyotas (Zuk)
He swears against the ARB for the Clamshell 8" front diff.

So far it's been really awesome in the truck. It definitely engaged and disengages much faster and quieter than the OEM locker.

My buddy just got the Harrop for his FJ. So far he really likes it. When I talked to ECGS, they didn’t seem to have any positive bias towards the Harrop. Maybe that’s changed or I just talked to the wrong guy.

 

[Theblackflag]

I talked to zuk a few months back about having him build a front diff for me with an ARB. He absolutely refused to even look at the ARB despite installing them in the past, however when I asked him why Harrop over ARB he wasn't able to give me any concrete reason other than "personal preference"

I'm obviously biased towards ARB as that's what I run in my truck and what my family members have always run, but I wouldn't ever run anything but the ARB. My parents have had front and rear ARBs for over 25 years without a single failure. I also love mine because at maximum the wheels can turn 1/16th of a turn before the locking mechanism is forced to engage and it has always done that. Near instant locking that remains locked no matter what untill I turn it off is what I want for a selectable locker.

While the newer harrop design is improved over the old Eaton design, my biggest gripe with it and that video is their logic of "there's always bind in the system" the will keep the locker locked when switching from forward to reverse. To me that would mean that all the time when you turned the locker off it wouldn't disengage either without a lot of fiddling to release that bind. I've personally wheeled with several trucks that have the harrops and they always disengage when switching directions or even just rolling back slightly, even in tight turns. It really makes smooth traction and power application much tougher.

To each their own I suppose though. That's why we have a lot of options available

 

[4runner DOA]

Electric lockers also have a solenoid that can jam up if it's not used regularly or cleaned or maintained. I was incredibly surprised when locked engaged on the Tacoma a few weeks back when I got stuck in the mud. I haven't turned it on in probably 7 or 8 years. Granted you can manually engage them if that happens.

 

[2ndGenJonny]

I'm not denying that ARB air is King, but for me I liked keeping everything electric. If I was a pure trail rig it would be air and solid axles, but this is my DD.

The Harrop did it's job and got me over a set of obstacles I never thought I'd make. So I'm definitely happy to have it vs. not.

Zuk refuses the ARB in the 8" ifs clam cause he's seen too many detonate that small diff according to him, He doesn't want to deal with that drama. Shit I've seen the flaming the internet does to ECGS when someone grenades a front diff.
He won't even warranty it when I spoke with him either. This is why I went with complete rebuilt 3rds from ecgs in the end. I had one issue with the seal, they sent me a new one no questions asked.

 

[Theblackflag]

That's an interesting reason for him to refuse to use the ARBs. Ive never seen any of the front clams grenades, plenty of front 3rd members, but maybe I'm not looking hard enough. They're an incredibly strong design because in order to chip a tooth all 10 bolts on the case would have to stretch and allow the whole carrier to shift which is highly unlikely. And having seen both the ARB and Harrop clamshell diffs the cases are near identical. The ARB has a slightly thicker ring gear mounting flange but I wouldn't think it was near enough to "detonate" the front end.

I think either one is head and shoulders above the Toyota E lockers. I would agree though if its a primarily street driven truck that just needs a locker once or twice a year the Harrop has its place.

Zuk's lack of warranty was another reason I opted to not go with him and just build my own diffs. I had ECGS build my rear 3rd last year and they were excellent to deal with. But I wanted to do it myself to save on time and money. Plus it isn't a bad skill to have and the tools are pretty cheap.

 

[4runner DOA]

That's an interesting reason for him to refuse to use the ARBs. Ive never seen any of the front clams grenades, plenty of front 3rd members, but maybe I'm not looking hard enough. They're an incredibly strong design because in order to chip a tooth all 10 bolts on the case would have to stretch and allow the whole carrier to shift which is highly unlikely. And having seen both the ARB and Harrop clamshell diffs the cases are near identical. The ARB has a slightly thicker ring gear mounting flange but I wouldn't think it was near enough to "detonate" the front end.

I think either one is head and shoulders above the Toyota E lockers. I would agree though if its a primarily street driven truck that just needs a locker once or twice a year the Harrop has its place.

Zuk's lack of warranty was another reason I opted to not go with him and just build my own diffs. I had ECGS build my rear 3rd last year and they were excellent to deal with. But I wanted to do it myself to save on time and money. Plus it isn't a bad skill to have and the tools are pretty cheap.

I've got a spare 3rd sitting in the garage that I plan on gearing and I'm strongly debating throwing a locker into it because if I throw the ring and pinion on a trail, I probably still need that rear locker to get out. I'm a little weary of correctly setting the lashing and what not though. I've never dealt with gears before.

 

[4Running Daily]

I had a Yukon Zip Locker (Air) in the rear of my 3rd gen originally. It was like my biggest mod ever when I was in high school. Supposedly it’s just an older ARB design. I never had any issues and it was quite a bit cheaper than an ARB.

But when I regeared, I opted to have ECGS build everything for me, so it was easier to just purchase 2 new ARB’s and selling my Zip Locker third separately.

I love my ARB’s, even if having OBA is a pain to setup and have it work well. With how much more expensive the Eaton Harrop is, I wouldn’t change a thing.

Plus, I purchased during ARB’s promotion where you get a free compressor with the purchase of 2 lockers. So that wasn’t an added cost.

 

[WileECoyote]

So, as someone had mentioned earlier about a Detroit Truetrac would having one in the rear help in most wheeling situations? I don't know how to better ask the question since I don't really "rock crawl", although rock crawling has varying degrees/difficulties. I think though, that I would consider myself a "light rock crawler".

@4runner DOA I SO PLAN on doing White Mountain this year if you have any plans... or that red dirt trail... would having open diff make it hard on those types of trails?

I find myself more on loose dirt/rock trails with some climbing of rocks. Sorry for constantly mentioning the trail for those that already know I did a solo run on, but "Swansea-Cerro Gordo Road" would be a perfect example of a typical trail I would go on. There was one part of that trail where I had to go through ice/snow conditions, didn't expect those conditions, but my back-end was slipping pretty good with open diff, is the best I can explain it. BUT, with that said, I rarely find myself in those situations.

I only plan on doing the rear and re-gear to 4.56 or 4.88 from 4.10. I have a 2.7L Reg Cab 4WD auto and stock. I know, auto's are for pu$$ies, but I LOVE that thing.

HAHAHA, anyways, that's the best I can describe the trails/examples/situations.

Finally, if things pan out, I MIGHT be moving to St. Louis pretty soon (I.e. snow). I really don't want to, for family reasons as some know, but it's my only choice if things work out.

 

[4runner DOA]

So, as someone had mentioned earlier about a Detroit Truetrac would having one in the rear help in most wheeling situations? I don't know how to better ask the question since I don't really "rock crawl", although rock crawling has varying degrees/difficulties. I think though, that I would consider myself a "light rock crawler".

@4runner DOA I SO PLAN on doing White Mountain this year if you have any plans... or that red dirt trail... would having open diff make it hard on those types of trails?

I find myself more on loose dirt/rock trails with some climbing of rocks. Sorry for constantly mentioning the trail for those that already know I did a solo run on, but "Swansea-Cerro Gordo Road" would be a perfect example of a typical trail I would go on. There was one part of that trail where I had to go through ice/snow conditions, didn't expect those conditions, but my back-end was slipping pretty good with open diff, is the best I can explain it. BUT, with that said, I rarely find myself in those situations.

I only plan on doing the rear and re-gear to 4.56 or 4.88 from 4.10. I have a 2.7L Reg Cab 4WD auto and stock. I know, auto's are for pu$$ies, but I LOVE that thing.

HAHAHA, anyways, that's the best I can describe the trails/examples/situations.

Finally, if things pan out, I MIGHT be moving to St. Louis pretty soon (I.e. snow). I really don't want to, for family reasons as some know, but it's my only choice if things work out.

Rear locker makes a huge difference. Regardless of crawling or not. Especially in loose stuff. You should keep an eye open for an elocker 3rd. I see them for first gens all the time. I think @Nicklovin might be sitting on one still.

And absolutely we can go run white mountain or red heep trail when you've got time. White is still one of my favorite "easy" 4wd trails and I haven't been back to red Jeep trail since that first time.

 

[rkntoy]

What about the Detroit trutrac? I know it’s not a true locker but it still should add a fair amount of traction and shouldn’t break cvs like lockers will. Has anybody ran one up front? I’m thinking about it when I regear my taco to 5.29s, I’m aware that if one tire comes off the ground it’s just going to 1 wheel and that’s ok but with the kind of wheeling I do there’s usually a lot of tire slip anyway so I think a limited slip would be perfect, and not hurt my ability to drift in 4x4 like an auto locker would

Depending on use of vehicle and transmission the TruTrac can be a great choice. Much better manners on road with compact snow and ice. And you can get them to work almost as good as a locker by applying a little brake pedal, which is much easier with an auto. I had one of these for years in my 86 4runner that I wheeled the crap out of. Light years better than any of the other LS options.

 

[AssBurns]

Electric lockers also have a solenoid that can jam up if it's not used regularly or cleaned or maintained. I was incredibly surprised when locked engaged on the Tacoma a few weeks back when I got stuck in the mud. I haven't turned it on in probably 7 or 8 years. Granted you can manually engage them if that happens.

The Harrop doesn’t have a solenoid, and the Toyota OEM locket uses a motor not a solenoid IIRC.




@Theblackflag good point about the idea of disengagement with the Harrop vs ARB. That little extra could be a bit more of a PITA when in a tight situation where you need to disengage to turn the wheel tighter. I am constantly engaging and disengaging my ARB up front to readjust or turn the wheel. The ARB is almost instantaneous with engagement, and pretty quick to disengage.

 

[RPS1030]

The Harrop doesn’t have a solenoid, and the Toyota OEM locket uses a motor not a solenoid IIRC.




@Theblackflag good point about the idea of disengagement with the Harrop vs ARB. That little extra could be a bit more of a PITA when in a tight situation where you need to disengage to turn the wheel tighter. I am constantly engaging and disengaging my ARB up front to readjust or turn the wheel. The ARB is almost instantaneous with engagement, and pretty quick to disengage.

Zero chance I’d ever run a Harrop in the big rocks. It only takes an unplanned split second of a corner not receiving power to suddenly slide and end up in a real shitty position.

 

[Theblackflag]

I might as well throw these up here. I recently did a full tear down on my front ARB locker since I bought it used and wanted to give it a good once over before install.

IMAG0761 by Phoenix Black, on Flickr

Here is the one of the only two moving parts in the ARB locker mechanism, the bonded piston seal as it is called by ARB. It's a rigid rubber oring that has two sealing ridges and moves a total of amount 10mms between locked and unlocked. In the background you can see the shallow side of the case that is splined to interface with the locking collar at all times, this is what allows the open diff to be turned into a full spool.
IMAG0763 by Phoenix Black, on Flickr

Now the locking mechanism itself. Here it is unlocked, in this picture I have the side gear resting in its bearing journal of the case with the locking collar in the disengaged position. Notice how the collar allows just enough clearance for the side gear to spin freely in turn allowing the open differential action. You can also see the small counterbored holes where the return springs rest. Its my understanding the newer lockers have switched to a one-piece wave spring further simplifying the locker.

IMAG0765 by Phoenix Black, on Flickr

And now locked. The locking collar is pushed up by the bonded piston seal when air pressure is applied and it then engages with the side gear mechanically locking it to the case turning the open diff into a full spool. Incredibly simple and incredibly strong. Also since the collar engages with the teeth of the side gear itself, which has 16 teeth in this case, the max amount of rotation before engagement is 1/16th of a turn at the wheels.

IMAG0766 by Phoenix Black, on Flickr

 

[Nicklovin]

Rear locker makes a huge difference. Regardless of crawling or not. Especially in loose stuff. You should keep an eye open for an elocker 3rd. I see them for first gens all the time. I think @Nicklovin might be sitting on one still.

And absolutely we can go run white mountain or red heep trail when you've got time. White is still one of my favorite "easy" 4wd trails and I haven't been back to red Jeep trail since that first time.

Oh ya huh.... I should get around to installing that. It'd help out a lot

 

[JTB727]

Granted im one of the few here still on little tires, i chose auto lockers front and rear. My truck is converted to manual hubs, although with my hubs locked and 2wd you cant tell on the highway or street because no torque is being applied to the front end.

The rear locker makes some noise when turning but overall i like it. If i have the radio on or ac i dont hear it.

The front lockright replaces the spider gears which is what I liked about it. Most front diff failures I have seen have been someone munching the spiders. So i no longer have to worry about that. Ive had them in for 3 years and ive broken 1 cv. I broke it in the stub shaft on a trip with @4Running Daily , @stumbles and @Blender. We originally thought my front locker broke, because my front was only applying power to one side...but it turned out to be the broken axle...

Overall id do it again. No air lines, no solenoids, no wiring. I can control the front lockup by how intense I hammer the throttle and same with the rear...

No my truck doesnt change lanes when I shift. (Yes its a 5 speed.)

No i dont spin out on the freeway in the rain

No i dont lose control in intersections.

No it isnt dangerous. But they flat out work. And now that ive had them they are seemless.

 

[KarlTyler]

I've never been a fan of auto lockers. Selectable all the way, especially if you ever drive on ice or snow. I don't love having to rely on OBA or C02 for the air lockers, and I still don't love the engagement, even though it's improved from the original design, of the Eaton/Harrop. Also I didn't see anyone mention the TJM pro locker or cable actuation conversion of the rear Toyota e-locker via Chilkat (or DIY for much cheaper with the right resources/knowhow). I have yet to come across any sort of cable actuation capable option up front, but this is what would appeal most to me. I'd also like to hear some opinions on builders. Never heard a single complaint about ZUK, but $$$$. I was pretty set on ECGS because of their great reputation, competitive pricing, quick turn around, and willingness to give me extra core credits for some extra 3rds that I have laying around. Then over this past summer, a slew of failed ECGS diffs popped up on social media specifically from backed out ring gear bolts. Have heard mixed reviews from Just Differentials as well.