GVs don't have a diff lock.

4H lock just sends an equal amount of power to all four wheels (4H sends more to the rear). 4H lock is fine on anything slippery.

And don't listen to Toyota drivers.

 

GVs don't have a diff lock.

4H lock just sends an equal amount of power to all four wheels (4H sends more to the rear). 4H lock is fine on anything slippery.

Hmmm...sounds like a differential lock to me. AFAIK, the "4H lock" position locks the center differential, which means that equal torque is sent to the front and rear differentials. The front and rear differentials do NOT lock, so individual wheels may still slip.

4L Lock is gonna keep the differential locked, but also engage a reduction gear in the transfer case so the effective gearing to the wheels is much lower through the gear range.

Personally, I would listen to your buddy with the Toyota, and only engage the locked positions in slippery conditions at slow speeds (if conditions are good enough to drive at speed, you don't need to lock anything).

 

4H lock is for better traction on your vehicle when having a slippery, snowy or rough roads. i drive my 08 vitara with 4H lock on highways during winter. still runs perfectly. maybe that guy with toyota meant 4L lock (all time 4x4)

 

Ok thanks, assumed when it said 4H-Lock it was a diff lock of sorts. Won't worry about it going to that setting in future. Towards the end of the snow (now all gone) i did just put it in 4H-Lock when moving off then back to normal 4H will just keep it there in future if it's slippy under foot.
At least i know what some of it's capabilities are of sorts and well impressed

 

I agree with Kootenanny. The GV version we're talking about is normally in 4H. This is the equivalent of AWD, with the centre differential, or transfer case, operating as a limited slip device. This allows the front and rear wheels to turn at different speeds, such as while cornering. (Ignoring the differences in wheel rotation rates on the same ends.)

But if the forces on the wheels become more uneven, the limited slip unit resists those differences. BUT, if the forces become very uneven, the limited slip's resistance is overcome and it allows wheelspin on the front or back. Or diagonally opposite.

In 4H Lock, the centre differential/transfer case is locked up. This requires the front and rear transfer shafts to turn at the same rate. There is no AWD/limited slip function. While this eliminates the possibility of the two front or the two rear wheels overcoming the resistance of the limited slip function in the centre differential/transfer case and so allowing wheelspin at one end, obviously this will creates a problem while cornering. It's not a problem on gravel, sand, snow etc, because the wheels can slide enough to relieve the stresses. But on dry pavement, it will put high stresses on the driveline. The Toyota driver is right.

I've also theorized that for highway driving on snow/ice, this enforced wheel slippage is more likely to cause a skid while cornering, than driving in AWD where all the wheels can adjust to the varying optimum rotation rates. I would only use 4H Lock in situations where speeds are low and there are no G forces while cornering.
I happen to believe that many of the upside-down suv's you see on corners in icy/snowy conditions are because of misuse of the locking center differential.

4L maintains the transfer case lockup, and cuts the gearing in half.

I don't think it's accurate to say the GV can "send the same amount of power to all four wheels". This would be true if it had lockers in the front and rear differentials. But it doesn't. It relies on brake traction control for this. ABS-based traction control is a poor substitute for the real thing, and the GV is set up to allow only a certain amount of power before the traction control gives up.

ABS-based traction control means braking, not applying power. If the GV had limited slip devices in the front and rear differentials, "applying equal power to all wheels" would be true up to the point where the limited slip units begin slipping. But the GV has open differentials at the front and back.

 

The transfer case employs an LSD for operation in 4H. When you place it in 4H lock a fork moves a sleeve locking the input shaft and output shaft. I had one apart that the LSD was overheated due to a binding front diff-the nylon inside the LSD melted and would intermittently cause the vehicle to stop moving unless 4H lock was selected. This particular GV burned up two transfer cases and had a lot parts thrown at it until I got ahold of it to figure it out. We drove 1000 miles after I made repairs and it was fine after that.

 

Your budy with the Toy is right. I'm using the Lock mode only in extreme situations.

 

Thanks for all replies, will just use it sparingly from now on.
After he told me i was just putting it on lock to get moving in the snow then reverting back to normal 4H, traction was good in whatever it was in.

 

After he told me i was just putting it on lock to get moving in the snow then reverting back to normal 4H, traction was good in whatever it was in.

This sounds right. BTW, my GV doesn't have the lock modes--it is a base model, with 4H only, and I get around just fine in the snow (I live in the mountains in BC, where it knows how to snow). I don't think I'd need to lock anything unless I was trying to take the GV offroad in very rough conditions. Snow on the streets?--4H works just fine for me.

 

I would expect more tyre wear to result from driving around on 4H lock position in normal conditions, and at normal speeds. In this scenario it may well put more stress on driveline components as stated above.

Whether this extra stress would lead to premature catastrophic failure is another question. There are always people who will tell you horror stories about cars, if you listen to them.

On the other hand I always tell Mrs B to leave the thing in 4HL if she is driving the lanes in a foot of snow at low speeds. Her feeling secure and reasonably confident is my priority.

 

This is our fifth winter with the GV. I have not yet been in a situation where we were unable to continue in 4H, but were able to continue in 4H Lock. And the same goes for 4H Lock and 4Low/lock. I have been stuck only once, and none of the modes got me out of it. (Shovelling did.)

I do switch down to better traction modes before having problems, so I don't know if I actually would have run out of traction in the higher modes. I sometimes mount chains before losing traction also. I use 4Low/lock more for engine braking on descents and lowering strain on the transmission for crawling up rough stuff, than for traction.

So I can easily see how GV's without the low range can perform just fine. You still have the GV's unbeatable weight distribution and full time AWD.

 

dkguffe is exactly right.

With most 4x4 vehicles, the transfer case is either engaged or not--and when it's engaged, it spins the front and rear driveshafts at the same speed. This is why most owners of 4x4s will tell you not to engage the transfer case on dry pavement (or indeed, any surface that has positive traction). Even on hardpacked gravel, my old 4x4 truck would buck and shudder when turning hard with the transfer case engaged.

The difference with AWD is that there is slip allowed between the front and rear axles, so they are allowed to spin at different speeds. In the GV, this is accomplished by the use of a "center differential," which, as the name implies, allows for differential speeds of the two driveshafts. Switching to "lock" mode locks the differential, and causes both driveshafts to spin at the same speed--just like a 4x4 truck. This may have advantage at very slow speeds, such as crawling over rocks or through deep mud, but otherwise I can't see much advantage (Low speed range is different...).

The "limited slip" part refers to the fact that the GV's center differential will only allow so much difference in speed between the two driveshafts. This is so that, if one set of wheels has no traction (say, they're on ice), the differential will still send torque to the other axle, even if it's not locked. Note, this is not the same as having a limited slip axle differential (which is what most people are referring to when they say, "limited slip differential.") A limited slip differential on an axle does the same thing, but it limits the speed differential of the two wheels on the axle (usually the rear axle). I don't know of any light vehicles that have locking axle differentials (they are common in heavy equipment and large trucks, though).

BTW, I used to own a 1980 Jeep Eagle wagon, which was one of the first AWD vehicles. It used a viscous coupling to transfer torque to the front driveshaft, rather than a differential...a simple device which actually worked quite well (that Eagle would go in the snow better than any vehicle I've ever owned, probably even better than the GV owing to it's greater weight...of course, you had to be a mechanic to keep it running...).

 

I've seen claims that the Mitsubishi Outlander from about 1999-2003 was able to lock both the centre and the rear differentials. I've been unable to confirm that, though.

The Jeep (AMC) Eagle was amazing. Except for the somewhat cramped interior resulting from using the body of a cheaper AMC car. Eagles had limited slip differentials on both axles, besides the centre differential. I once had the luck to drive an Eagle sedan up a steep slippery road. No vehicle did any better, and most did much worse. People stared in amazement because it looked like a normal car. I always resented Subaru advertising the Outback as "the world's first sport utility wagon", because the Eagle predated it.

 

The Worst American Cars - POLL

 

Interesting take on the Edsel. I thought the reason it bombed was because the front grille resembled something else, rather than a "nose"

 

I remember reading somewhere that with new GVs that have standard ESP, there is no need for an LSD. What does that mean? (can't find the link, sry)

I'm driving a '09 5d 2.4 GV with 4H-4HL-4LL, but without ESP (believe it's a Middle East model) and am trying to find out what features I do have in my drivetrain... I'm hoping the group assembled here will have an idea about this!

 

not where I read it initially, but here I also found:
All Grand Vitara models are now equipped with ESP® stability control, eliminating the need for a centre LSD.

 

That must be some of the most meaningless drivel I've had the misfortune to read.
I quote:-
The bold front face and sleek distinctive styling gives the Grand Vitara the muscle it needs to tackle rugged terrain as well as the agility needed for everyday driving.

How does styling give muscle and agility?

I suspect what he should have written re the lsd was it no longer needed a rear lsd perhaps?

 

hah, yeah, sorry for that... the original site I read this on wasn't much better. Anyway, it seems they didnt put standard ESP in 09 GVs for all markets. As far as I know my GV has no ESP, no TCS, only 2 airbags.

So how do I find out whether I have LSDs in Tcase/diffs or not? when I put my VIN in the EPC I see a front and rear diff which dont seem to have any LSD parts, but 6 types of transfer case (2 without low gear, 2 with low gear and LSD and 2 with low gear without LSD). wow this is confusing
(thats in the electronic parts catalog 2.5.3 Software 2009-06, Data September/October 2009)