Overland Journal Project Land Rover Discovery 4 (LR4)

[Scott Brady]

Glad to see it on some rocks! 12" of ground clearance sounds pretty good with the push of a button.

How does the optional rear locker in these work? I assume it is not driver controlled, so does it still need some wheel spin to engage? Then does it disengage after a preset time or something? Just trying to wrap my head around what's going on in there. I suppose I have the same question about the center diff - wheel spin to engage the lock or is it more of a viscous coupling thing?

Looking forward to your rover comparison write up!

It is a true locker and the engagement depends a lot on the terrain response setting you select. The unit we tested would agressively keep the center locked and almost always keep the rear locked when in rock mode. On the visual display, it has three levels of 'assessment', when affects how long the diff remains locked. They are little bars that make a circle around the lock symbol. The more bars that are highlighted, the greater the 'assessment' and longer it stays engaged. The reality is, it all happens automagically.

The Jeep Grand Cherokee Final Drive II has a similar system, but it is better overall than even the HD LR4. More effective and quicker to respond. The previous generation even had a locker in the front, which also engaged automagically. The traction system could write all kinds of checks the body had no business cashing. Given that, the new GC and the LR4 with the HD are very comparable on the trail. The GC has a better traction system, but the LR4 has a much better suspension, with more articulation.

This shows the 4x4 info screen for the truck we have. If it was the HD version, there would be a rear locker symbol too. You can see the bars that make up the locker pie on the display.

 

[1leglance]

I am driving a 1970 Chevy Suburban...that means it is 42 yrs old. I wonder what it will be like to drive the LR or Jeep system in 44yrs? Will the wiring survive? Will the computers? Of course we might be hovering over the terrain just like we thought we would be by now.

What are the effects of a computer malfunction in the field? If a wire comes loose, gets abraided or a sensor fails? Does the system default staying raised or lowers itself?

I guess all the electrical stuff scares me but then again I am not a target market and in reality none of us on this forum in the USA really go far from pavement & tow trucks in the USA.

 

[Scott Brady]

All new cars are an appliance. Some have a longer service life than others, but all have an ending. 20 years is possible with regular use, but 42- no way! It is really unfortunate and reflective of so many products we purchase anymore. Think of a flat fender Jeep. Over 70 years of serviceability - incredible. I bet driving around in a flat fender Jeep or or Series I Land Rover would be more fun too, even though it would be slow, loud, unreliable and require constant service. But think of the smiles.

I have been looking hard at buying an old Series Land Rover or Flat Fender Jeep. There was a beautiful flat fender in the Omix Ada booth at SEMA.

Just look at this- perfect

or this 66 Series II- timeless

Of course this is a romantic notion as these vehicles are timeless, but terrible. The LR4 does everything better, except last forever.

Still might buy one though

 

[JAK]

I am driving a 1970 Chevy Suburban...that means it is 42 yrs old. I wonder what it will be like to drive the LR or Jeep system in 44yrs? Will the wiring survive? Will the computers? Of course we might be hovering over the terrain just like we thought we would be by now.

What are the effects of a computer malfunction in the field? If a wire comes loose, gets abraided or a sensor fails? Does the system default staying raised or lowers itself?

I guess all the electrical stuff scares me but then again I am not a target market and in reality none of us on this forum in the USA really go far from pavement & tow trucks in the USA.

Here is my answer. If you short the right wires you are stuck. On my LR3, the drivers front ABS sensor harness wore through and shorted to itslef. This was result of the previous day's run or lazy mechanic not putting the harness back where it belonged after the brake change. As everything on the LR3 and the LR4 are tied to the ABS you end up losing, ABS, HDC, Terrain Response and the vehicle lowers to access height. It took me about an hour to find the problem and fix it before a run the next morning in Death Valley.

The challenge of working with these trucks makes the experience all that more satisfying and frustrating. It is not enough to turn a wrench anymore; you have to know the electrics as well. This is a double edge sword, but all part of the experience for better or worse.

As fo 44 years from now, I'm not sure we will be allowed to experience the liberty of taking our trucks out. The carbon credits alone would be disastrous.

 

[Fivespddisco]

it required several seconds of wheel spin before the system slowed the spinning wheel sufficiently to allow forward progress again. This makes it difficult to modulate. [/QUOTE]

You have to overwork these trucks a little bit to get the traction control to engage. I fear it is a trend with modern traction controlled vehicles. Coming from an old-school truck it's like learning how to drive again.

Spin spin spin the tires when they grab let off the throttle,..... repeat at next obstacle

 

[nwoods]

You have to overwork these trucks a little bit to get the traction control to engage. I fear it is a trend with modern traction controlled vehicles. Coming from an old-school truck it's like learning how to drive again.

Spin spin spin the tires when they grab let off the throttle,..... repeat at next obstacle

Not necessarily. We joke that the TC systems and terrain control is like adding an "easy button" to the dash, but in truth, properly using the TC requires an adroit sensitivity to the throttle and what the wheels are doing. Sure, anyone can get through, but to finesse it requires a bit more practice and learned technique. No different really than engaging an ARB locker on a 35" jeep and pin pointing through a rock pile. The LR3/4 can be driven in similar circumstances without wheel spin once you learn how.... and have proper tires

Geat pics Scott, and thanks for the feedback. I was a little surprised not to hear you talk about the significantly different lines the LR4 takes instead of the Disco. I always found that the most interesting comparison in the trail. With the low points on the chassis being very different, different bumper angles, and much sharper turning radius, it's like driving a totally different trail.

If you ever do a trip in that rig somewhere west of you, I'd love to join you. Or if you need someone to TAKE the LR4 on a western trail for photos or whatever, I'm always ready.

 

[Scott Brady]

The algorithm is the algorithm in rock mode and it requires wheel spin to engage. That is why the HD package with rear locker is so important and reflects my preference as a driver, which is to never overwork a truck. The LR4 with standard traction control does not need to be overworked, but it does require a specific driver input.

Effectiveness is determined by the responsiveness of the system. A Tundra for example has the worst traction control effectiveness we have ever tested. The LR4 requires rapid tip-in and then back off to moderate throttle position. This allows the system to begin working as quickly as possible, but minimize potential damage to the drivetrain and trail. Unfortunately, it has limited modulation. It is certainly better than most and benefits from good articulation for an IFS/IRS vehicle. The traction control is better on the LR4 than the DII as it has a multi-mode system that can be set to 'rock' which improves responsiveness and effectiveness.

Regardless, it is impressive what stock vehicles can do with just traction control now. I think of how a stock LR4 would fare against a stock Discovery I. Having owned and wheeled both in stock form, the LR4 is magic. A lot has changed in 15 years. Now that the LR4 and our DI are modified, it will be fun to take them on the trail and compare the apple and orange. Each has its charm.

 

[Scott Brady]

I will say my #1 goal for the LR4 right now - 18" rims and a 33" tire. It is currently an outside linebacker walking around in 4" pumps. . .

 

[Mbogo]

I will say my #1 goal for the LR4 right now - 18" rims and a 33" tire. It is currently an outside linebacker walking around in 4" pumps. . .

LOL! What were they thinking with that wheel and tire combo? A go-cart has more sidewall!

 

[Fivespddisco]

Will the 33s fit in in the wheel well ?

 

[toddz69]

The Good
1. I really like the Kaymar rear bumper system. It is simple and clean, complimenting the lines of the truck and relocating the tire to the bumper.

Scott: Curious if you have any thoughts on the rigidity of the Kaymar tire mount on washboard/corrugated road surfaces. I did the "shake test" on your truck and a few others with Kaymar bumpers at SEMA and was disappointed in their lack of mounting rigidity.

Thanks,
Todd Z.

 

[Scott Brady]

Will the 33s fit in in the wheel well ?

Even a 35 will fit with some work. Lots of measurement and research in Iceland. A 265/70 R18 is ideal IMO and measures 32.6" actual height.

 

[Scott Brady]

Scott: Curious if you have any thoughts on the rigidity of the Kaymar tire mount on washboard/corrugated road surfaces. I did the "shake test" on your truck and a few others with Kaymar bumpers at SEMA and was disappointed in their lack of mounting rigidity.

I have not noted any noise from the bumper and have driven quite a bit of corrugation. We also have about a month with these bumpers in Australia and I never noted any noise. It is a pretty well proven design.

 

[PhyrraM]

While I do not disagree with the need to change wheels and tires, the 'dubs' DID make it through the trail and weekend - and survived.

I'll be looking forward to your report when you do install the new shoes.

 

[poncerover]

Great Build!
Quick question.
Looked and could not find who manufactered the rock sliders or were they custom built?
Really like that they are made of aluminum.
Looking forward to seeing your continued progress.