LR3 (Discovery3) ARB Rear Locker installed

[morrisdl]

I was un/fortunate enough to follow a LR3 HD around for a day and saw how significant the little differences actually are. I did more difficult trails that day than I have ever done and got stuck on a rock climb and needed a winching (the HD did not). The HD LR3 was slow and steady, where mine always needed a little more throttle and drama to get though the same things. The HD would walk over an obstacle where the traction control (TC) needed a little wheel spin to kick in. Before that day, I was perfectly happy with the capabilities of the TC. I have always kept up with the Defenders and Jeep Rubi in our groups. The locker should just makes it a little easier on the truck, tires, and trails.

ARB sells two models: RD218 for the rear axle and the RD217 for the front. My Rear ARB locker came with new TIMKEN bearings. There is a warning on the ARB store that not all kits do. I know Lucky8 sells the bearings too (if needed). Thankfully I did not attempt this install. It was completed by Corey Rice @ Land Rover Knoxville, TN. His skills are probably more than what is required for this install, but this guy is one of the few that has rebuilt LR3 diffs. He is also one of the organizers for the Fall Uwharrie Land Rover event and an amazing mechanic. He worked late into the evening to make sure my truck was ready for me.

I put the compressor switch in the touchscreen relay and the physical rear Locker switch behind the parking brake. This combination worked out well to prevent accidental activation AND ease of use on the trail:

Install specifics: Used factory 75-90 synthetic oil. Change again after 500-1000 mile break-in period. Backlash was .015 and preloaded was rotational torque of 1.5NM. The ARB Kit did not come with a new pinion depth/preload crush sleeve. The LR tech luckily had a new one left over from a previous diff rebuild.

Pricey mod, but getting stuck sucks!

 

[A.J.M]

Be very interesting to see this in action with videos, also curious how yours got stuck and the HD one didn't. Was it the same line or just not able to get enough traction?

It's a future mod i'm considering for my own D3, the active rear diff is a very rare option for D3/4's in the UK.

 

[perkj]

It'll be interesting to see how the ARB locker compares to the factory HD locker out on the trails. Keep us posted.


The added benefit of the factory HD locker is that it enables itself automatically only when needed (stupid simple) so it keeps the added stress of the locker on the diff to a minimum when compared to a manual locker.

 

[MontyMog]

Awesome!!!! Any plans for the front? That is also the same place I mounted my arb compressor

 

[morrisdl]

Be very interesting to see this in action with videos, also curious how yours got stuck and the HD one didn't. Was it the same line or just not able to get enough traction?.

The locker makes a measurable difference. I have long muddy rutted hill climb on my property. We took a ten runs at it and I had my passenger randomly switch it on/off the locker with out me knowing and track the results. Made it up 3 of 5 times with it Locked and only 1 of the 5 times without. By the end of the test I could 'feel' if was on or off.

I tried to recreate last years uwharrie Daniel trail climb video where you can really see my TC working hard, but last year was dry and this year was total mud. The trail has change significantly and was not passable. WIll try again this fall.

The time following an HD was at break over point at the top of a 6 foot tall rock face the full width of the trail. Both LR3's high centered in the same place, but mine was spinning more and started sliding sideways to a potential roll over situation. My non-HD maybe would have made it once the TC kicked in, but for safety sake I stopped and winched over the top.

 

[morrisdl]

No plans for the front. Im happy with traction for now. Hidden winch is on the short list. Maybe dedicated sets off road / on road wheels if I find a cheep set of wheels.

 

[zelatore]

Very interesting - although it's been on the market for a while this is the first I've read of somebody actually installing one.
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I have the stock locker in the rear of mine but occasionally wish I could manually control it. Not enough to replace it, but I have thought about doing the ARB front.
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Or I could just build a RRC rock crawler and be done with it. The LR3 is many things, but it will never be a hard core trail rig no matter how much I pretend it is.

 

[SDLR3]

I know this might be slightly off subject. I have a LR3 with HD. What I am curious about is the use of the TC. Do people turn the DSC off when offroading? I had gone out a few times and it felt like there was this delay when I had it on. When I turned it off it just kept things moving. I have been trying to research the proper use of the the settings. TIA

 

[Dmarchand]

I tend to shut off the DSC in low traction (wet) conditions. Otherwise I keep it on on rocks.

 

[A.J.M]

From experience, there is no hard and fast rule for leaving it on or turning it off.

Just experiment and see what suits you, the car and the terrain you are on.

 

[morrisdl]

One more variable to consider is hill decent control (HDC). I dislikes it and always turned it off util last week in the uwharrie mud. It was an absolute necessity...strangely dsc seemed to work better on the assents when both were turned on. No idea why it works, but I will leave it on now.

 

[jerdog53]

I turn both the DSC and HDC off when off road, I have used the HDC twice during some long rocky descents.

 

[nwoods]

I know this might be slightly off subject. I have a LR3 with HD. What I am curious about is the use of the TC. Do people turn the DSC off when offroading?

Always, without exception, turn off DSC when off roading. DSC retards the throttle, and in my experience, does so at the exact wrong time when you really need a bit more throttle. The sole exception might be monkey snot mud. And mostly then too. IMHO.

 

[SDLR3]

Always, without exception, turn off DSC when off roading. DSC retards the throttle, and in my experience, does so at the exact wrong time when you really need a bit more throttle. The sole exception might be monkey snot mud. And mostly then too. IMHO.

That is what I experienced with what felt like no power and explains a lot.

 

[morrisdl]

It could be coincidence, but I felt the same way against DSC until the locker was installed. Could also be because I was also in "monkey snot mud" all weekend. My tactics are definitely slower and less throttle needed than ever before. Maybe DSC and HDC were primarily designed and tested with the HD LR3 in mind. Unlike in the past, I had no problems getting some revs to spin the tires as needed with the rear locked.