I'm going crazy trying to find out what they mean..

Why go crazy when it's all on the owner's guide? If there's something specific you don't get after reading the guide, I'm sure you can get help here on the forum.

 

Thats why I'm here

 

N : Only for when you tow the vehicle behind another ride.
4H : This is your normal mode. I'm still confused as to if this means like AWD or they activate when they detect slip.
4H-lock : Actual differential Lock 4 wheel drive.
4L-lock : Low gear differential Lock 4 wheel drive.


Plus as said i know its in the manual, but i dont have mine on hand to quote it.

 

4H : This is your normal mode. I'm still confused as to if this means like AWD or they activate when they detect slip.

Hmm? 4H means constant four wheel drive, with 53% of the torque going to the rear wheels and 47% to the front. This makes the car behave slightly rear wheel driven (at least unless you have ESP.)

4H-lock : Actual differential Lock 4 wheel drive.
4L-lock : Low gear differential Lock 4 wheel drive.

To clarify: in these modes, the center differential is locked which means the rear and front axles are spinning at the same speed. The front and rear axle differentials are still not locked, i.e with one side spinning all torque goes to the other side (unless you have ESP which brakes the spinning wheel.) A non-ESP car will get stuck if, say, the front right and rear left tires loose contact, even if you're in center Lock mode.

 

Here's a long-winded version....

N - neutral, the center differential is disconnected from the transmission. So when you tow it, the engine and tranny are inactive. Or if you're not towing, it can roll away on you.

4H - the center differential is a limited slip in this mode. The front and rear "axle" differentials are engaged. The GV doesn't have axles in that sense because the fully independent suspension requires the use of shorter shafts with constant velocity joints. The front and rear differentials are what's called "open", which means they are simple. These simple differentials are funny. On one hand, they have no ability to allow the different turn rates such as happens during cornering. On the other hand, if a wheel starts spinning, they put all their power into uselessly spinning the wheel lacking traction. This means that on pavement, cornering is impaired, while on slippery surfaces, they allow useless wheelspin.

A completely plain center differential, when engaged, will still allow the front, or the back, or two diagonally opposite wheels to spin when the traction difference/power differential reaches a certain point. And yes, that's pretty useless. At the same time, when on pavement, the system is so locked together that when cornering, the system will build up and release stress to the point where the vehicle does something that's aptly described as "crow hopping".

The GV's limited slip center differential locks the wheels together (up to a point) but at the same time allows for slippage for cornering. This is equivalent to an AWD setup. Limited slip differentials can be built to provide varying amounts of resistance to slippage. The "stiffer" they are, the more they resist wheelspin, but the more they resist the wheels turning at different rates. Sometimes, when backing up with the wheels at full lock, you may experience some lurching or clunking noises from the drivetrain. That's because of the stiffness of the limited slip differential. The stiffer the differential, the more stress you place on drivetrain components.

On the GV, traction control using the ABS and the brakes is used to detect and stop wheelspin, which makes up somewhat for the lack of lockable or limited slip differentials at the axles.

So what this means is that in 4H, the GV drives through all four wheels, and the slippable center differential allows being in 4wd on pavement because the slippage allows for cornering.

4H Lock. After explaining that, it's easier to understand 4H High. 4H High means the center differential is locked. This makes it more like an old fashioned simple system. On one hand, the front or rear wheels, or two diagonally opposite wheels theoretically can't spin. I use the word "theoretically" because of something I'll get to later. You shouldn't use this mode on bare dry pavement because you don't need it, and because it will stress the driveline components, cost mileage, and induce unwanted forces into cornering dynamics.

I would suggest NOT using this mode for slippery highway driving. The reason is that when you initiate a turn, even a slight one, a locked center differential will resist wheels turning at different speeds. It wants them all to be turning at the same rate. In a corner, this will cause one or more wheels to slip relative to the road surface. A wheel sliding even a tiny bit has a huge loss of the traction you need for cornering. In combination with the high center of gravity and stiffer suspensions, this is why you see so many SUV's in the ditch on the first slippery corner in sudden winter conditions. In this mode, they are actually worse than 2wd.

The tighter a limited slip differential anywhere on the vehicle is, the more it will tend to do this same thing. The one time I slid off the road with the GV, I believe this played a role. I was in 4H on a extremely slick road, going into a corner. I think one or more wheels started slipping, just from the stiffness of the center differential. The road was so slippery, the yaw forces were so low that the stability control system did not activate even after I steered more sharply into the corner. I should have applied the brakes, so I wouldn't have gone so far off, but I ran out of time to think about what to do.

This slippage is ok when "off roading" because you don't have the cornering forces trying to throw you into the ditch, and things happen more slowly.

4L Lock. The only difference here is that the center differential has two gears, and this engages the second of them. This gearing halves the speed in any given gear, so you can climb steeper hills, engine brake more slowly downhill, or creep through really rough stuff.

Notice that there's no 4L.

And drifting off topic a bit...

Now, I have been in a situation where I was in 4L Lock, climbing fairly steeply on a gravel road, with a diagonal ditch to cross. In fact, it's the one in my avatar picture. Though it's not apparent in the picture, the ditch was too deep to cross perpendicularly without hitting the bottom. So I had to go through the ditch more in line with the ditch, which meant doing an "s" turn to sort of go up the ditch as I crossed it. This resulted in two diagonally opposite wheels being unloaded, and given the power I needed to climb the hill, the GV came to a stop with the unloaded wheels spinning. I was kind of shocked by this, since this was exactly why I wanted a 4wd with traction control. The traction control was active, as evidenced by plenty of clacking noises from the spinning wheels.

I had to take the ditch at an angle closer to perpendicular to keep the weight more on all four wheels. This meant I had less clearance, but I made it without scraping. Obviously this was not a problem coming down the road, since you're not applying power.

I expect the traction control system is set to use the brakes only to a certain point for a couple of reasons. One is to prevent overheating the brakes, as you would in a sustained situation like this. The other is that the more aggressive the traction control system, the stronger the driveline components have to be. For instance, say you were on an extremely steep hill with only one wheel having traction. All the force to lift the vehicle's weight would have to go through that one wheel. This is why the people who build extreme off-road vehicles, with all differentials locked, break driveline components.

Any solution to this, such as dialing up the traction control, or making the front and/or rear differentials limited slip or lockable, would require strengthening the driveline.

I guess I wouldn't mind if Suzuki or the car reviewers gave even the slightest hint of this in their specifications or reviews, but I was greatly disappointed at the level where I ran into this compared to the claims made for the GV.

 

geevee,

I like your writeup except for one thing. Simple differentials DO allow for the wheels connected to them to turn at different speeds including going around a corner. That is why you can get stuck with them. The center differential is not needed to go around curves. I have a 2WD and thus no center differential and I go around curves just fine.

I have experienced the traction control once that I know of. I was pulling my boat (~2,000 lbs) out of it's normal parking place under the screened in porch and the GV was on wet grass. The boat had to make a turn and go up the hill. My son thought I'd tear up the grass but I thought I would be OK and I was right. We both smelled something when I got the boat up to the street that smelled like burnt clutch. I am not sure if that is what it was or it was the brakes. My son was outside the GV watching and noticed the rear wheels moving in small jerks indicating the brakes were being applied by the traction control. I have no off-road or even gravel road experience yet but I think the traction control is nice to have.

Jim

 

Thanks, Jim.

As I was writing that, I was aware I don't fully understand the open differential. For instance, it's open because as you said, it has to allow varying wheel rotation speeds on corners. Yet I don't get why it "holds" until a wheel starts spinning, then loses all the power into that wheel.

 

I think this 4H L or 4L L are sales gimmicks. I got stuck once in wet snow and then in deep send. Wheels were spinning regardless of the mode selected and I didn't see any evidence that the traction control got activated.

 

4h or 4l only changes gear ratios not whether TC works or not

 

Hey guys, if any of you ever bothered to put down the sunvisor.. there should be a DANGER warning telling you NOT to use 4H or 4L lock in wet pavement or dry pavement. I had to see why so I tried it.... thats me!

So when I turn tight especially in wet conditions some of the wheels actually LOCK and will infact cause you to slide just by turning the wheel. The car will even come to a standstill without you even trying pressing the brakes (steering turned to left or right)... I find almost no use for the GV to be driven in either of the Lock modes on paved road!

I also tried the N position. You can actually drive it on 2 wheel drive except you have an alarm that sounds every 10 seconds or so. In this mode the GV does actually feel lighter on the road, but if you accelerate a bit hard in like when coming out af a parked spot the steering becomes extremly heavy.... have no idea why.

Then Finally there is the option to press brake and clutch while holding the control further down to the N position. This compeltly disconnects the motor from the gearbox, and in the manual it states to use this position for towing you car. (always with 4 wheels on the ground)

BTW my GV is a Manual 5 speed without ESP.

 

Thanks for the experiments and insights, kenmalta. I hope your dealer doesn't read this discussion.

I should add to the driveline discussion that the GV's setup allows it to play in two worlds. One is that the limited slip center differential, while in 4H High mode, allows it to use 4wd on dry pavement, like an AWD vehicle. In 4H Lock, it is like an old-fashioned 4wd, which is better than AWD for offroading, but which you can't use on dry pavement.

Our GV replaced a '91 Pathfinder. The Pathfinder had a old-fashioned 4wd system, with the benefit of a limited slip rear differential. It could not be driven in 4wd on dry pavement. Driving it on a road with patchy ice required coming almost to a stop to engage 4wd and the front hubs, then manually switching in and out of 4wd as we passed from dry pavement to ice. Even then, sometimes the driveline didn't like doing this. The Pathfinder had better articulation and clearance than the GV. The limited slip rear differential acted on the whole driveline for a benefit similar to the limited traction control on the GV.

So the GV's system is far better for highway driving. The GV is impaired by poorer clearance, no skidplates and limited articulation. A much better highway vehicle, but not as good as the Pathfinder for summer offroading. However in winter, the GV's perfect weight distribution makes it simply vastly better on snow and ice.

 

The operation of these systems certainly seems more complex than the advertising would lead one to believe. One limitation they don't mention is that the traction control system will apply the brakes only up to a certain level of pressure. I would imagine there is also a time limit of some sort. This is necessary both to prevent overheating the brakes, and to protect driveline components from breaking. Which is why if you floor the GV and keep your foot in it on a loose or slippery surface, it will give up and let you spin the wheels.

I have had the GV stuck once, and I similarly felt the choice of mode had little effect. Unfortunately I didn't think to turn off the traction control. The result was that the thing would lurch badly, and whenever the truck spun wheels, it would slide sideways closer to a concrete barrier. (Which I eventually left paint samples on.) There was no way to "finess" what was going on. Not enough gas and nothing happened. To much and various wheels spun and braked, and the thing lurched sloppily. I believe it takes a wheel rotation before spinning is detected, so in a situation where inches matter, having the various wheels gripping, braking and spinning independently means you have no fine control.

However, that's the only time we've had the GV stuck among many opportunities to do so. So I think it's very good at not getting stuck to begin with, and no system will get you out of everything. I do wish it had a more sophisticated system that detects minute amounts of wheelspin. And I wish new car journalists tested this sort of thing, or got the information from the manufacturers. It's like reporting that the GV has heated leather seats, but not mentioning that they have no user-adjustable settings.

4L Low definitely is not a gimmick for extremely steep hills, extended creeping, or engine braking down long, steep rough descents.

 

its called axle wind up. ALL 4wd vehicles do it. Thats why you are not sopposed to put it in 4wd in dry high traction conditions. You could possibly do damage to the transfer case. Tho I do put in 4wd every few weeks to excersize it. I just don't make sharp turns and only do it for a few miles.

Hey guys, if any of you ever bothered to put down the sunvisor.. there should be a DANGER warning telling you NOT to use 4H or 4L lock in wet pavement or dry pavement. I had to see why so I tried it.... thats me!

So when I turn tight especially in wet conditions some of the wheels actually LOCK and will infact cause you to slide just by turning the wheel. The car will even come to a standstill without you even trying pressing the brakes (steering turned to left or right)... I find almost no use for the GV to be driven in either of the Lock modes on paved road!

I also tried the N position. You can actually drive it on 2 wheel drive except you have an alarm that sounds every 10 seconds or so. In this mode the GV does actually feel lighter on the road, but if you accelerate a bit hard in like when coming out af a parked spot the steering becomes extremly heavy.... have no idea why.

Then Finally there is the option to press brake and clutch while holding the control further down to the N position. This compeltly disconnects the motor from the gearbox, and in the manual it states to use this position for towing you car. (always with 4 wheels on the ground)

BTW my GV is a Manual 5 speed without ESP.

 

its called axle wind up. ALL 4wd vehicles do it. Thats why you are not sopposed to put it in 4wd in dry high traction conditions. You could possibly do damage to the transfer case.

It is worth mentioning that unlike the XL7s, the newer GVs have a full time 4wd system. It differs from the on demand system in some other SUVs, such as the Rav4, where the vehicle by default is front wheel drive until slippage is detected when the rear wheels get fed some power.

The GV's system, on the other hand, drives all four wheels all the time (alhtough with a bias to the rear). The ls centre diff prevents driveline windup and damage to the transfer case. When you switch to High lock or low range, though, you can damage things.

Tho I do put in 4wd every few weeks to excersize it. I just don't make sharp turns and only do it for a few miles.

Oh, but it can be such fun! Just look here!

 

Sorry to jump in here, but is 4H the same as AWD vehicles??

 

Sorry to jump in here, but is 4H the same as AWD vehicles??

Similar but different. 4H drives all 4 wheels thru an unlocked centre diff, AWD commonly uses a viscous coupling or a clutch type system

 

On this model 4H IS AWD - there are different types of AWD systems, some use viscous couplings to link the front & rear, some use electronically activated clutches, others, like this one, uses a center differential.

Depending on your particular vehicle, the center differential may or may not be lockable, the ones that are not lockable are AWD, the ones that are lockable have the N-4H-4HLock & 4LLock switch and are AWD in the 4H position.