When to engage center diff (transfer case) lock?

[Radix Junior Member Find all posts View Profile Close Radix]

Would you engage center diff lock (HL instead of HH) anytime you travel on a dirt road, or only occasionally?

As this Prado is all-time 4WD, is there any need to. Why/why not?

Just looking for some tips/best practice.

3400 Petrol 95 series

[pradosteve97 Junior Member Find all posts View Profile Close pradosteve97]

In slippery sand or mud maybe on the beech is about the only times I've used High Lock I've used low lock heaps more times maybe that's relative to where I go

[JimmyC Advanced Member Find all posts View Profile Close JimmyC]

According to the course I did last week the centre lock should go on as soon as you leave the bitumen (the convo was geared towards the 150 series though).

[hawks667 Member Find all posts View Profile Close hawks667]

I reckon I've used HL about 4 times and they have been on sand.....for the generic/corrugated dirt road stuff, I leave it in HH & adjust tyre pressures accordingly.

If i need full traction, i go straight to low range...

[r4ndll Avid PP Poster! Find all posts View Profile Close r4ndll]

There's lots of views on this. It's like the petrol diesel debate.

Personally I use it most of the time on dirt roads (especially ones I don't know), and all the time on dirt when towing, and all of the time on sand. Most of the dirt roads I drive are twisty NP tracks not straight outback roads. Do I need to? Probably not but its mostly for safety (I drive a 120 without stability control).

It's not an all time 4WD until the diff is locked btw. The first section of this vid demonstrates that quite well. http://youtu.be/EBmw6Wpfe6M

[Corigator Avid PP Poster! Find all posts View Profile Close Corigator]

I was a fan of not using the centre diff until really necessary. I thought it would not force wheels to slip. I changed my mind on the Simpson. Engaging the centre diff stopped a lot of digging in on the dunes.

[JimmyC Advanced Member Find all posts View Profile Close JimmyC]

In the Simpson only drove occasionally with it in. The sand was so hard packed from rain that the only time I used it was across lake poeppel and big red

[Brett1979 Avid PP Poster! Find all posts View Profile Close Brett1979]

From my personal experiences I've found there is no advantage using HL over HH. For the last 5 years at least Ive just completely skipped HL and gone straight from HH to LL. I havent been stuck in sand for years and do just fine on gravel roads with HH. I've belted along at 80-100km/h all the way up the Peninsula Developmental Rd twice in Cape York and The Sevannah Way with 18 psi in the tyres. If you can drive properly you don't need HL. HL comes into its own for rally cars taking dirt bends hard and fast. Those cars also have the power on tap for all 4 wheels to be spinning in excess of the speed the car is doing around a loose bend and the front wheels spinning on the gravel in unison with the rear helps steer the car in the direction the front wheels are pointed.

For a "heavier, under-powered, un-rally-car-like" Prado there is no advantage whatsoever. Just drive it properly in HH or LL, with the right tyre pressures and you don't need to ever use HL for any terrain.

If you feel you need to use HL on a gravel road to keep traction or to feel safer then you're driving in a dangerous manner that will see you wrap your car neatly around a tree if you're not careful. Just remember, it's not a rally car so don't drive it like one.

LL in soft sand for a 4wd such as a Prado or heavier is so much more superior than HL and much more responsive in the soft stuff provided you've hit it with the correct amount of speed initially and or are in the correct gear.
From a stationary position in soft sand, LL will get you moving forwards or backwards better than HL ever will.

During a dry hot spell in Byfield NP, if you think HL would get you up the long uphill very soft sand track into 5 Rocks then you've got another thing coming.

I can't comment on HL's use for snow driving though as I've never driven in snow. I'd imagine it'd be the only time that HL would be of benefit over the other gears here.

[Boxy1 Lurker Find all posts View Profile Close Boxy1]

I generally only use LL for long steep sandy hills or rocky climbs and descents. I like the fact that my engine just purrs along in HL, at normal revs while driving on sandy tracks or along the beach. No need to be in LL with the engine revving so high unless you are struggling to keep revs in the soft stuff.

[LeighW Avid PP Poster! Find all posts View Profile Close LeighW]

When driving through deep Bull dust I find HL works well.

Deep water crossings I use LL.

Sand dunes such as big red HL.

Mud HL.

Gravel HH as I have stability control.