Locker vs Open

[muskyman]

changing out the side gears is really not hard at all.

the way to do it is treat it like one of those baby toys where you stack the colored rings.

now this depends on what model ARB you have as well. The New RD128 is a two piece unit

http://www.arbusa.com/uploads/PDF/onlineManualsGuides/2-RD128.pdf

the Ring gear retaining bolts are what hold the case together. so what you do is remove the ring gear and then unstack the unit piece by piece laying it out on the bench.

then you will come to the cross pinion shafts that are retained by three retaining bolts these are cap screws in the RD128's case. These come out from the oposite end of the locker from the ring gear ,once you remove these and the spider gears that ride on them you can lift out the second side gear.

The other model is the older but still common RD56/RD57

http://www.arbusa.com/uploads/PDF/onlineManualsGuides/2-RD56.pdf

this is a three piece case locker and you can leave the ring gear in place and take it apart from the other side. this uses 4 pins to retain the cross pinion shafts these are exposed when the cover is removed.

once again lay everything out on the bench in order and it really isnt a tough job to do.

if the unit is a RD 56/ RD 56 and has alot of miles on it replacing all the trust washers in the unit will tighten it back up and take up some of the lash that developes because of wear.

 

[I Leak Oil]

Thanks, that looks simple enough. Good to know about the thrust washers too.
Jason T.

 

[LC/LR4Life]

There are lots of reasons that second Rangie could have had problems. Bad tires, poorly chosen line, it sure looked to me like the driver didn't understand what finesse was.

No, the problem was he didn't have a locker and that is why he was spinning his tires off. The driver couldn't finesse anything, because he didn't have locker(s). If he was equipped with a locker, or two lockers even better, he could have literally crawled right up and over that obstacle on the hill without even spinning a tire.

 

[muskyman]

gone

 

[revor]

That may seem like the easy answer, and a locker will take a average driver and make him look good. But there are techniques that will also help to know.

left foot brake modulation with many trucks will make you think a guy is running lockers when he isnt.

I drive my truck with both ARB unlocked about 98% of the time offroad and tip toe through things that I watch guys with lockers struggle at.

never think its all about lockers, the driver still is the most important piece of equipment.

Now wait a minute! Musky! It's cause you are an off road GOD when it comes to technique!!!

Actually Musky's right! I rarely use my lockers and the 110 hasn't any yet. When I do use the lockers the center diff is usually open. Lockers make it easy but they're hard on the driveline, I try to preserve the driveline by not using lockers if I don't have to.

Driving the 110 without has been a new learning experience, and an enjoyable if not stressful one. I'm learning how to drive this truck, once I have a clue how it will perform I'll stick the lockers in. It's actually more fun and more of a challenge! I guess it's hard to explain but it's like learning how to drive all over again!
More than Lockers I want lower low range gears! More control! I'm one set of 4.88's away from that!

 

[LC/LR4Life]

That may seem like the easy answer, and a locker will take a average driver and make him look good. But there are techniques that will also help to know.

left foot brake modulation with many trucks will make you think a guy is running lockers when he isnt.

I drive my truck with both ARB unlocked about 98% of the time offroad and tip toe through things that I watch guys with lockers struggle at.

never think its all about lockers, the driver still is the most important piece of equipment.

In this case, it was the locker which helped the first RRC up and over easily. I've seen it all before, and you can only do so much with technique. The comparison was between basically a rig with a single rear locker, and a rig with open diffs. The first one was up and over in literally seconds, the second, struggling over and over with no traction. The rig with open diffs was quite apparent in the video.

 

[Antichrist]

That's presumably because that type of LSD is not available for Land Rovers

More or less true. In the 60's a Rover LSD was available. I've seen one US Rover that came with one (it had been replaced when I saw the Rover, but was on the dealer ticket). From what I've read they were pretty crappy and I've never seen a used one for sale.

the driver still is the most important piece of equipment.

How quickly people forget that! Or just never learn it.

 

[michaelgroves]

In this case, it was the locker which helped the first RRC up and over easily. I've seen it all before, and you can only do so much with technique. The comparison was between basically a rig with a single rear locker, and a rig with open diffs. The first one was up and over in literally seconds, the second, struggling over and over with no traction. The rig with open diffs was quite apparent in the video.

I'm with muskyman on this. It's hard to tell what another driver is doing wrong (especially from a video), but the difference between success and failure can be very subtle. One vehicle can bounce and spin wheels and dig holes, and get stuck half way up time after time, then the next truck, identical, can cruise all the way up without any fuss whatever. It's not easy to say exactly what's being done differently - it's about the precise line chosen, the gear selected, the speed, knowing exactly the moment to give it a bit more throtte, or back off a bit, how to make unavoidable bounces work for you instead of against you, etc.

Not to say lockers don't help - of course they do.But I'd put my money on a more experienced and expert driver to get around almost any course with open axles, in preference to a mediocre driver with locked axles. (One exception is a course designed specifically to foil open diffs - the type so beloved of the vendors of traction control systems and locking diffs!)

 

[michaelgroves]

left foot brake modulation with many trucks will make you think a guy is running lockers when he isnt.

Presumably you're talking about a truck with a LSD here?

 

[michaelgroves]

When I do use the lockers the center diff is usually open.

I've given this a lot of thought over the years and it's complicated to analyse (especially with a six-wheeler! )

What's your reasoning? (Specifically, versus, say, locking centre and rear?)

When I do use the lockers the center diff is usually open.
More than Lockers I want lower low range gears! More control! I'm one set of 4.88's away from that!

The problem with using diffs for low-range reduction is that you have lower gears in high range too. (When you say you're looking for lower gears and more control, I assume you mean lower than on a stock vehicle?)

An underdrive is a useful bit of kit, and gives you all the low gears you need, without detracting from your top end. It has a spin-off benefit that it gives you some in-between ranges to select - very handy if you sometimes run laden and sometimes unladen, for example.

The downside is that it's expensive. Also, I suppose it's quite nice to do the gear reduction as far "downstream" along the drivetrain as possible, so that you're stressing as few components as possible...

 

[muskyman]

gone

 

[LC/LR4Life]

I'm with muskyman on this. It's hard to tell what another driver is doing wrong (especially from a video), but the difference between success and failure can be very subtle. One vehicle can bounce and spin wheels and dig holes, and get stuck half way up time after time, then the next truck, identical, can cruise all the way up without any fuss whatever. It's not easy to say exactly what's being done differently - it's about the precise line chosen, the gear selected, the speed, knowing exactly the moment to give it a bit more throtte, or back off a bit, how to make unavoidable bounces work for you instead of against you, etc.

Not to say lockers don't help - of course they do.But I'd put my money on a more experienced and expert driver to get around almost any course with open axles, in preference to a mediocre driver with locked axles. (One exception is a course designed specifically to foil open diffs - the type so beloved of the vendors of traction control systems and locking diffs!)

You have some valid points there, but we aren't discussing the driver, we are discussing the video showing open versus locked. I can guarantee you, take one experienced driver, do the line with each of the rigs in the video and he will have much more difficulty with the unlocked vehicle.

I've seen it myself in person with my own vehicle. Mine locked, anothers unlocked. First guy took 20 minutes plus to get up a hill full of ruts and ledges, tires spinning rocks all over etc, and what happened with me? I drove up the same way he did, which took all of about 30 seconds and no tire spinning.

 

[muskyman]

You have some valid points there, but we aren't discussing the driver, we are discussing the video showing open versus locked. I can guarantee you, take one experienced driver, do the line with each of the rigs in the video and he will have much more difficulty with the unlocked vehicle.

I've seen it myself in person with my own vehicle. Mine locked, anothers unlocked. First guy took 20 minutes plus to get up a hill full of ruts and ledges, tires spinning rocks all over etc, and what happened with me? I drove up the same way he did, which took all of about 30 seconds and no tire spinning.

I think you are missing the point.

 

[michaelgroves]

Nope

modulating the brakes has become better known by people running a gear driven limited slips but it is in no way only for LSD drivers.

A open diff transfers torque in a 50/50 ratio at all times. if you use the brakes to keep a tire from breaking traction you then increase the torque applied to the tire with traction.

once a tire breaks traction the amount of torque that it is transferring is very small thus the tire on the other side of the diff is only transferring that same amount of torque.

Applying the brake to the spinning wheel only, yes. Applying the brake to both wheels on that axle, no - at least not from the explanation you've put forward.

Consider a single axle (for simplicity), where one wheel has minimal traction and the other has excellent traction. How will braking both of them equally help? Yes, you "artificially" increase the torque on the spinning shaft, but the resulting increase in torque on the other shaft is fully absorbed by overcoming the equal braking effort on that side.

I can only see two ways in which BTM (brake/throttle modulation) might help (marginally) with a open diff, and both of them apply only if the vehicle has got a mechanical fault.

1) If the brakes are not pulling evenly, and it so happens that the side with more braking has less traction.
2) If the diff has got a hell of a lot of internal friction, and it somehow gets amplified by the high braking torque.

 

[muskyman]

gone