4WD and Hilux Pickups

[Nicely]

OK, read a few posts on engaging the different 4WD modes, but have an additional one.

The Pickup has some sort of manual twist knob in the middle of the front wheel. How does this work?

[kitesurf_phil]

OK, read a few posts on engaging the different 4WD modes, but have an additional one.

The Pickup has some sort of manual twist knob in the middle of the front wheel. How does this work?

Sounds like you have free-wheeling hubs. They disengage the front wheels from the drive shafts and front prop, thus cutting down your fuel consumption, as the engine isn't wasting power driving something that is not needed. The only thing you have to watch is forgetting to get out and engage them before you go off road, otherwise you could find yourself in low rear wheel drive.

[Nicely]

So, I need to twiddle the knob (so to speak) if I want to engage 4WD (high and low)?

One other thing. When low gear 4WD is engaged, should it lock the diffs, i.e. both sets of wheels operate together rather than independently.

[Vagrant No2]

So, I need to twiddle the knob (so to speak) if I want to engage 4WD (high and low)?

One other thing. When low gear 4WD is engaged, should it lock the diffs, i.e. both sets of wheels operate together rather than independently.

The free wheeling knob is to be turned to locked if/when you want to use 4wd at any time , high or low . It does not lock the diffs .

[Nicely]

Thanks. I thought low gear 4WD needed locked diffs to be of any use...? Otherwise the wheels would be constantly spinning independantly on uneven surfaces.

[TonyN]

One other thing. When low gear 4WD is engaged, should it lock the diffs, i.e. both sets of wheels operate together rather than independently.

Both sets of AXLES operate together in 4WD, high or low. You still have open diffs in each axle.

Don't get a Hilux confused with something that is allwheel drive like a disco or range rover, they have a diff in the tranfer case to allow it work on the road, their diff lock is in the transfer case, locking it gives you same 4wd setup a Hilux in 4wd.

[Nicely]

OK. Here's the reason I asked.

I stuck it into low for reversing up a very steep uneven drive the other week, the LH rear wheel went over a slippy bit and spun. The RH wheel would not drive whilst the LH was spinning. I hasten to add that I didn't know about the free wheel knob then, so the fronts weren't doing anything.

[TonyN]

OK. Here's the reason I asked.

I stuck it into low for reversing up a very steep uneven drive the other week, the LH rear wheel went over a slippy bit and spun. The RH wheel would not drive whilst the LH was spinning. I hasten to add that I didn't know about the free wheel knob then, so the fronts weren't doing anything.

Yeah, you were still in rear wheel drive, high or low doesn't matter, without the front hubs locked in the front drive stops in the hubs.

[Nicely]

The same thing would happen at the back (or front) though if one wheel went over slippy ground. Is this correct?

[TonyN]

The same thing would happen at the back (or front) though if one wheel went over slippy ground. Is this correct?

If one wheel on each axle is on slippy stuff or in the air, yes you'll lose traction. But the only way round this is diff locks.

[Nicely]

If one wheel on each axle is on slippy stuff or in the air, yes you'll lose traction. But the only way round this is diff locks.

Understood.

Is a diff lock something which can be added?

[TonyN]

Understood.

Is a diff lock something which can be added?

Yeah, you have various options, auto lockers are cheaper, but have some things to be aware off, they take some getting used to when turning - the inside wheel powers your truck around the corner, while the outside wheel is 'freewheeling'. With an open diff, the outside wheel does the powering. Automatic lockers are cheaper than the ARB air locker and provide the same traction, though there is some ratcheting noise and wheel hop on the road. They can cause some spooky steering on slippery surfaces.

Manual lockers are better as they are more predictable, especially in the snow/ice as you can decide when you want to use them. ARB or try and find the hugely rare Toyota electric locker that comes in some import pickups or 3rd gen US 4Runners, but if you don't get the whole axle some work is needed to fit it in a standard axle housing.

Quite a few 4Runners and Surfs have a LSD in the rear, which quite usefull for work on loose surfaces.

The cheapest option, while sounds a bit overkill works well if you want to offroad alot is to weld the front diff up, like having a spool in the front, you'll get 100% traction both sides in the front as long as the hubs are locked and its in 4WD. The down side is steering becomes a little odd, and you'll have to jump out and unlock one hub when its not slippery.

[Nicely]

Thanks.

Any ball-park prices for the ARB auto and manual lockers?

[TonyN]

Best off doing a search for shops, Lockrites used to start at about £300, ARB's often top £700 by the time you've got the locker and compressor.

both need some fitting skills/costs, the ARB more so as you need to set the diff backlash and preload again afterwards.

[Nicely]

OK. Thanks for the help and advice.