4WD on Bitumen Surface

Lock the hubs and use low range in the wet.

Windup is a consideration but lesser of 2 evils.

One trick is to ensure the wheels with tyres are the same diameter by adjusting air pressures.

Also don't have tyres up to high , lower pressures give better traction on bitumen at low speeds same as dirt, but only lower if you still slip.

Al

I reckon if the bitumen is wet and slippery enough that you have wheelspin,
then it is slippery enough not to worry too much about windup problems either
Cheers,
CJ

Is the driveway straight or curved,the more curved the more windup will occur,if straight it should be fine with all wheels engaged,i have driven patrols in low range with front hubs unlocked without a problem several times.

I always use low range with the hubs UNLOCKED for maneuvering trailers/vans, much less strain on pretty much everything.
I would not have a problem using this method in your situation in on dry driveway, I very much doubt you will do any driveline damage, damage is much more likely to occur with shock loading, such as spinning wheels suddenly gripping while you still have boot into it.
If traction becomes an issue, lock the hubs, if it's spinning with the hubs unlocked than I doubt "windup" will be an issue, but once you are in place and ready for maneuvering, unsure the hubs are unlocked,

Shane

Hi Al, for years I used low range with the free wheeling hubs in 'UNLOCK' on boat ramps because the boat was heavy and the ramp steep. Lower speed going down the ramp for better control and accuracy, and no slipping the clutch going back up with the boat on. If anything lower your rear tyre pressures to ensure you have 100% traction on the climb up the hill with the van on. Cheers, Kanga.

Another vote for using low range 4wd with the front hubs unlocked for manovering trailers....it slows everthing down and makes things much easier.

as for the wheel spin.

Slowing things down will reduce the incidence of wheel spin and improve control.

If however you have continued problems with wheel spin....there is obvioulsy enough slip that transmission wind up will not be an issue.

As for defating tyres......not at all a reliable way of preventing transmission wind up.

Delfating tyres may however improve your traction....how much ...well that is a good question that can not be answered unitll we know what tyre pressures you are running.

Another thing that may reduce your wheel spin.....is putting something in the back of the vehicle...50 to 100 KG can make all the difference.


cheers

Hi Al
Lock the hubs in and select L4x4 for the speeds you are doing , wind up will never be an issue, for any 4x4
Get into it and don't be scared of what you have heard.

Col

On the 80 series we do the "centre diff lock mod" which allows you to engage low range without engaging diff lock. It is used for the purpose for reversing trailers up curved bitumen hills in low range.

So instead of auto centre diff lock when engaging low range it allows you to engage and disengage it manually by the button. It a great mod for what the OP needs.

That diff windup would NOT be a problem over the 120 metres distance.

I would therefore use the front wheels locked in when wet or if traction is a problem, no problems there I reckon. Low range wheels unlocked is also OK.

If however you were driving down the highway on bitumen for 10K or so I would say don't do it, take it out of 4wheel drive, but 120 metres. Not a problem.

The small amount of diff windup can easily be unwound once you have the caravan up where you want it and unhitched. All you have to do is reverse slowly till you can slip the gear lever out of 4 wheel drive, then get out and unlock the hubs. Not a problem.

These vehicles were made for that small amount of bitumen work. I can't see what all the fuss is about. You can get far more damage to the drivetrain on a dirt track sometimes.

Much better to be safe than sorry, if that heavy beast gets away with you there will be hell to pay.

Cheers, Bruce.

The bitumen was completely dry couple of days ago so I tried using low range with the front hubs UNLOCKED.

Just sneaked up at 1200rpm. Appeared to be no problem so I think this is the way to go.
I might use locked hubs but only if the bitumen is wet.

Rgds,
Al

It's the main thing that disappoints with my Prado, no low range unlocked!