200 Series ARB Front Locker (or alternative) Install on 2016+ 5.7L LC200? (1 Viewer)

[Oman4x4]

I'm in the middle of installing ARB lockers front and rear on my Middle-East spec 5.7L 2017 Land Cruiser with the 8 speed and 3.307 ratio - unfortunately run into a big problem with the front as the RD151 ARB locker isn't actually compatible. The mounting flange for the ring gear seems to be in completely the wrong place to put everything back together. Only now I've seen that the ARB lists the locker as not compatible with my spec and N/A for a solution for my spec.

But we already have the locker and want to make it work.

If the issue is primarily the 3.307 ratio - does anyone know if I can use this locker in my 2017 housing if I were to select a different ring and pinion ratio? Or do I need a 2015 housing also?

I want to keep the ratio as close to stock as possible - I'll ultimately be going with the 74Weld Portal boxes down the road when they release them so I don't want to aggressively re-gear the axles as I'll be on a 22% reduction at the hubs later which will be plenty for the tires I'm planning to run (37" KO2) - I don't mind going a little lower on the gearing but what's the closest to 3.307 I can get for a 2015 housing and RD151 locker?

What was the stock gearing on a 2015 5.7 with the 6 speed and does anyone make anything closer to the 8 speed gearing because I'm assuming most people wanted a lower ratio not a higher ratio?

Alternatively, does anyone make a selectable front locker, or a torsen LSD locker that would work with the factory 2017 3.307 housing?

Appreciate everyone's advice as the Cruiser is currently on the lift in pieces. I have had a search but not coming up with a whole lot of info. Thanks in advance.

 

[bloc]

2008-2015 5.7 200s had 3.9 gears, at least in the US. The reason your diff carrier is different is the 3.3 ratio required a larger pinion head (to get 13 teeth on it) and this made the ring gear unacceptably thin. So they moved the ring gear flange over to allow for a thicker ring gear.

I just double checked and the housings between early and late models are the same part number, so that part works out. The challenge for you will be finding a 3.3 gear set that can work with the diff carrier flange in the original position. As stated above there is a good reason not to build those gears. On top of practically no demand for tall gears.. everyone increases tire size and therefore wants lower gearing.

@bjowett is kindof a wizard with different factory Toyota gear sets.. he may have some input. But I fear that to run that locker you may be forced into a shorter ratio than you’d want for those portals.

 

[Oman4x4]

Done some digging on ToyoDIY and it seems like the differential housings are the same part number from 6 speed to 8 speed vehicles but the differential carrier is different along with the ring gears.

Both share the 41141-34010 housing for the shallow side and 41111-34050 for the deep side of the diff housing.

2017 8 Speed - 3.307 ratio (43:13)
- 41301-60170 for the diff carrier
- 41201-80794 for the factory 3.307 gear set I currently have.

2015 6 Speed - 3.909 ratio (43:11)
- 41301-60150 for the diff carrier - it is a different part number which makes sense. I won't need this as I have the RD151 ARB locker.
- however there are two different part numbers for the gear sets....
- 41201-80481 *FGR=43:11=3.909 (01/2012 - 04/2015)
- 41201-80602 *FGR=43:11=3.909 (05/2015 - 07/2015)
Not sure what the difference is between the two of those... but as there is only one carrier part number and only one housing part number that is common to both - I assume either will work so will just get the most recent one?

And obviously I would need to re-gear the rear axle to 3.909 also.

Has anyone successfully done this?

3.3 to 3.9 is quite jump - 18% gear reduction combined with 22% gear reduction with the future portals would be a combined 44% gear reduction (1.18 x 1.22 = 1.44) - does anyone make a 3.58 or 3.73 gear set that would work with the RD151 ARB Diff (aka 2015 spec carrier?)

A 37" tire vs the factory 31.5" tire is a 17% increase in diameter so a combined 44% gear increase is going to be massively overdoing it I think.

So... Any other front traction aid options for retaining the 3.309 ratio in the front end?

 

[Oman4x4]

But I fear that to run that locker you may be forced into a shorter ratio than you’d want for those portals.

I think I just reached the same conclusion while taking the time to run the maths.

Appreciate the input. Any alternative LSD or selectable lockers I could run in the front with the factory 3.309 ratio?

Super frustrating that ARB hasn't manufactured a solution still. The car has been on the market 8 years and they still don't have a version of their diff with the mounting flange moved slightly. Insane to me when it's the dream car for a lot of their customer base.

 

[bloc]

Super frustrating that ARB hasn't manufactured a solution still. The car has been on the market 8 years and they still don't have a version of their diff with the mounting flange moved slightly. Insane to me when it's the dream car for a lot of their customer base.

In their defense you are asking for something very few people need. Nearly everyone putting lockers into an 8-spd rig are also increasing tire size and would be more than happy to toss in some used 3.9s for perfect gearing, which negates the need for a specialty ARB locker.

I think even portals becoming available won’t change that market much considering their maintenance needs and serious up-front cost.

But no, I don’t know of any traction devices for the later model carrier spacing. But others may have been paying closer attention..

I’d really wait to see what jowett has to say.

 

[Oman4x4]

In their defense you are asking for something very few people need. Nearly everyone putting lockers into an 8-spd rig are also increasing tire size and would be more than happy to toss in some used 3.9s for perfect gearing, which negates the need for a specialty ARB locker.

I think even portals becoming available won’t change that market much considering their maintenance needs and serious up-front cost.

But no, I don’t know of any traction devices for the later model carrier spacing. But others may have been paying closer attention..

I’d really wait to see what jowett has to say.

Thanks Bloc, yeah I know the portals will be a rare option but I was really hoping that I could benefit from sharing a need with people that want to run the lockers with a relatively stock tire size.

At the end of the day a rear locker is better than none, but really wish there was a way I could get the front to happen. I'm assuming machining the back face of the ring gear down would weaken it too much?

 

[bloc]

At the end of the day a rear locker is better than none, but really wish there was a way I could get the front to happen. I'm assuming machining the back face of the ring gear down would weaken it too much?

Safe assumption. You’d probably have to anneal the steel before machining, then have to heat treat it again. And increase the depth of the bolt holes. And that’s if you can get a good surface with the bolt holes already there.

And all of this is after Toyota deemed it necessary to build a whole different diff carrier because they were uncomfortable with the ring gear stiffness.

You’re right.. a rear only is a lot better than none.

 

[Boston Mangler]

Paging @TeCKis300

 

[TeCKis300]

The above maths checks out and I'm not aware of further options. Only answer I can come up with is 42s on portals. Paging @MTKID

 

[Boston Mangler]

The above maths checks out and I'm not aware of further options. Only answer I can come up with is 42s on portals. Paging @MTKID

Speaking of portals…

I saw this the other day right down the street from me…

 

[stellite]

I am pretty sure that going to 3.90 gears will be a plus. I would not hesitate if I were you. If thats all you need to do to get the locker, do it, IMO

 

[Oman4x4]

Speaking of portals…

I saw this the other day right down the street from me…

View attachment 3761507

That's a cool spot! Yep that one has the same brand of portals I'm hoping to get - 74Weld - the 200 Series is in the R&D queue and hopefully will be launching early next year - I'm hoping to fit them over the summer which is our down-time here when it's 48 celcius / 120 farenheit.



I can't wait to have that kinda ground clearance.

 

[sdnative]

@Justsendit

 

[Oman4x4]

I am pretty sure that going to 3.90 gears will be a plus. I would not hesitate if I were you. If thats all you need to do to get the locker, do it, IMO

Yeah in the short term the 3.90 gears would be a plus - the only downside is once I add the 74 Weld Portals when they become available, that multiplies the 3.9 out to 4.75 and that'll just be way over-geared I think considering it started at 3.3.

The 3.3 ratios with the portal boxes gets multiplied out to become a 4.0 ratio.

If the portals weren't something I'm very committed to having then I'd be happy to jump to the 3.9 ratio. Actually it would be the right thing to do. But I'm hoping that's only about 6 months away at most so I really don't want to just kick this problem 6 months down the road and then have to deal with it - would rather solve it now.

 

[TeCKis300]

Speaking of portals…

I saw this the other day right down the street from me…

View attachment 3761507

Nice. The 250 got portal fotment first over the 200. Quinn is hoping to release 200/tundra fitment later this year

 

[stellite]

Yeah in the short term the 3.90 gears would be a plus - the only downside is once I add the 74 Weld Portals when they become available, that multiplies the 3.9 out to 4.75 and that'll just be way over-geared I think considering it started at 3.3.

The 3.3 ratios with the portal boxes gets multiplied out to become a 4.0 ratio.

If the portals weren't something I'm very committed to having then I'd be happy to jump to the 3.9 ratio. Actually it would be the right thing to do. But I'm hoping that's only about 6 months away at most so I really don't want to just kick this problem 6 months down the road and then have to deal with it - would rather solve it now.

I can understand that, but also, chances are that with portals, you will likely go to a much larger tire, which will bring gearing back down.

 

[Oman4x4]

So fortunately the shop doing the install also recently did a 3.9 ratio Land Cruiser and still has the old part. Mine with the 3.3 carrier is on the left, the 3.9 carrier on the right. The ring gear is actually engraved 3.9 and it's just the pinion gear that's different for my 3.3 setup, and as a result of using the 3.9 ring gear the mounting flange is lower when positioned like above.

I'm leaning strongly towards attempting to machine the ring gear and see how we go.

With some basic calipers I've measured my mounting flange is 5.0 mm below the other one.

The ring gear bolts I believe are 7/16" aka about 11 mm - the mounting depth of the screw threads in the ring gear is already 17.33 mm so shaving 5 mm off the mating face of the ring gear would leave 12.33 mm in the screw holes so should still be able to get a 1:1 ratio of thread length to thread diameter. Seems to be plenty of clearance on the ring gear bolts to the casing so a 5 mm washer on the bolts shouldn't be a problem.

The car that recently had the ARB lockers fitted that gave us the OEM 3.9 carrier to compare to is a modified turbo diesel running over 1,000 Nm of Torque and the owner enjoys brake-stand launches so I figure if he hasn't destroyed that ring gear yet I should be fine with 5 mm missing from mine. I'm running the stock 5.7 with a gentle giant overland driving style.

I think it's worth a shot - worst case scenario we go back to stock and no locker, or see how bad the stacked up regearing will be. But in the hopes of being able to get it "perfect" we're gonna give this a try.

Next step is to accurately measure everything and go from there.

 

[Oman4x4]

Nice. The 250 got portal fitment first over the 200. Quinn is hoping to release 200/tundra fitment later this year

Exactly. I've been annoying Quinn for about a year so far haha. Would love to get them installed this winter if my finances are in place and I can get them shipped out here in time.

Makes sense to chase the 250 first - closer link to the Tacoma and 4Runner platform and that's where all the new-money will be for the hot new thing - but I'm glad the 200 is still on the to-do list. The 250 is impressive but I'm keeping my 200 for life. I just like the big lazy V8. They won't make another one.

 

[Oman4x4]

I can understand that, but also, chances are that with portals, you will likely go to a much larger tire, which will bring gearing back down.

Yeah I'm already planning on being on a 37" BFG KO2 with the Portals. But the portals are already perfectly geared for the 37s.

After the ARB Locker Install is done it's going to Arctic Trucks for the fender cutting and body and chassis modifications to clear 37" tires. It'll be on a combination of suspension spacer lifts (to retain my King 2.5" shocks) and body lift temporarily and then when the portals come in, the spacer and body lifts come off and we try to dial the Kings in as close to factory ride height as possible and let the portals do all the lifting. The goal is to already have the body modifications in place to be running the 37" tires immediately once the portals are on, and the wide arctic fenders will give me the tire coverage with the additional portal width.

I always wanted a Hummer H1 or a G4x4squared - I figure portalling my 200 will actually be a better end result than both of them, and while it's an expensive build, it'll be considerably cheaper than either of those.

Also will be finishing off with ARB front and rear bumpers when the fenders are done. The end goal is essentially something like this but 37 instead of the 35's pictured, and the height coming from the portals rather than lift.

 

[Oman4x4]

The above maths checks out and I'm not aware of further options. Only answer I can come up with is 42s on portals. Paging @MTKID

I mean... I am tempted to fit the portals first before removing the lift and see what that would look like with 42s hahahaha - but I think that'll just be too tall for our off camber dunes. I think 37's on "no lift" is the sweet spot. My Raptor is on 37s and I park it next to the 200 and I'm excited to see that much tire on the 200 soon. It'll be plenty.