When and how to use the off road capabilities of the Montero

[quailchaser]

It may be a stupid question, but what is the center differential? I'm aware of front and rear differentials and transfer cases, but the reference to a center differential has always confused me. Is it just the differential on the front axle?

 

[bugshield]

It may be a stupid question, but what is the center differential? I'm aware of front and rear differentials and transfer cases, but the reference to a center differential has always confused me. Is it just the differential on the front axle?

I wouldn't call myself an expert on the subject but some all-wheel-drive systems use a center differential in, or in place of, the transfer case. This allows the front/rear wheels to travel at different speeds as needed in high traction situations typical to all-wheel-drive mode on roads.

I'm not sure which Monteros the term center differential correctly applies to. My 2005 has a viscous coupling so I'd bet that it lacks a true center diff but I may be wrong on that or you may be able to correctly apply that term to the viscous coupling as it provides the same function.

The interesting thing about Monteros, to me, is the availability to select 2WD, AWD, or 4WD. Essentially it takes the advantages of a standard part-time 4WD and adds the unique ability to operate as an AWD. Throw in a good traction-control system and you have a great versatile vehicle.

 

[mtnblue]

I want to continue this discussion, because I am not sure I understand....

4HI is like AWD with an open center diff- can someone explain how AWD works and how it is different from 4wd? I just thought it was an updated version of 4wd. And is it true you can use 4HI on dry pavement without damage to the vehicle (because it is like AWD).

By locking the center diff, what exactly does that do? I know it sends power to both the front and the rear, but it just allows for the tire on both the front axle and the rear axle that has the ability to spin.... to spin right? in other words, it puts it into true 4x4?

And of course, the rear locker locks it up so the back two tires spin at the same rate in a straight line... right?

Is there any trick when done off-roading to get it out of gear? Back up? or just do it? I honestly haven't had a chance to use it in 4wd yet, but as soon as it snows I guess I will have lots of opportunity.​

 

[Salonika]

I know that some modern AWD systems actually rely on the brakes to achieve the AWD effect. The wheel speed sensors detect a wheel spinning faster than the others so the computer applies the brakes on the slipping side to make the opposite side turn. The Montero (not sure about Gen-3 and newer) version of AWD (Active Trac) doesn't work that way, I know that. I don't have lockers and I've been stuck before in 4wd with center diff locked, and one front wheel turning and the other not. I then used the winch.

 

[mtnblue]

Here's my answer from wiki: "The system offers a choice of four rear- or four-wheel driving modes, selected using a lever mounted alongside the gear shift, and can be changed while the vehicle is in motion.[SUP][2][/SUP] In 2H mode the front axle is disconnected and the vehicle is rear-wheel drive. Reduced frictional losses in the drivetrain mean that fuel economy improves while noise levels are reduced.[SUP][2][/SUP] 4H is a part-time four-wheel drive mode using a viscous coupling unit (VCU) and center differential to direct drive to the front wheels when the rear axle loses traction, and is capable of handling a wide variety of road conditions and speeds.[SUP][3][/SUP] 4HLc locks the center differential to provide extra traction for sandy, snowy or poorly surfaced roads in "high range" mode, while 4LLc, the "low range" mode, also offers a much lower gearing, providing the maximum amount of traction. Changing between 4HLc and 4LLc is only possible with the vehicle stationary.[SUP][3]"[/SUP]