Wind up in a 4x4

[havenoideaatall]

How serious is this?

A friend of mine tells me she feels safe in a 4x4 as when it is wet she puts it in to 4wd.

I was under the impression that without dirt, mud or sand this could cause a problem eventually. No idea how long it would become a problem after. seems to me the whole point of 4x4 is that you are locking the drive to all wheels thats the point.

Does a limited slip differential make this practise OK? Worse? No difference?

Does it depend on the sort of 4x4 "mechanicals" in use - would a newer soft roader be better for this, with the old workhorses with manual hubs a no no for this practise.

cheers

H

[journeyman Mick]

Depends what sort of transmission set up it has. On most 'traditional' type 4wd set ups like older cruisers, landies, hiluxes etc etc it's a really bad practice and can lead to at the very least very difficult steering and great difficulty disengaging 4wd and in extreme cases to major component damage. There's now all sorts of fulltime/partime/smart systems so without knowing what it runs it's not really possible to say. If it has free wheeling hubs or self locking/auto hubs it definitely shouldn't be run in 4wd unless you're in mud/snow/gravel/sand etc. If it doesn't then you need to consult the owner's manual or talk to the dealer.

Mick

[Schtoo]

It does happen, and it's a really safe way to make sure you completely destroy most of the driveline in the shortest possible time...

Actually, I used to run my Hilux in 4WD high for 5 minutes or so when it rained to keep everything freed up and lubed. Says to do so in the manual, and it caused no harm but I wasn't running all the time. Either way, running in reverse for a few metres is supposed to make wind up go away, although I never tested that theory myself.

Windup comes from the front axle and the rear axle travelling different distances, specifically when turning corners. Manual hubs, you get no drive to the front wheels unless the hubs are locked, so no problem if the hubs are free. LSD either end doesn't matter since the windup is front-rear not side to side. Side to side is easily let up when turning a corner, so it's a non-issue.

Full time 4WD uses a centre diff, which includes most soft-roaders. The centre diff keep front to rear balanced so no wind up.

I had mine would up once (mistakenly) and let it go wound up. It's a mistake I only dared make once, since the noises are pretty horrific when you know who will be paying the bill for new parts. And genuine Toyota parts are not that cheap...

Short version, don't do it. It's for when grip is waaay down, like maybe the first rain after a month of dry. In that case, it should hurt any, will improve traction and the slick road should reduce any wind up to a minimal level.

I personally think the right rubber makes up far more than flicking a switch, and sensible driving even more so.

[Iain]

Current Landrovers, Rage Rovers, Landcruisers, Jeeps are full time four with a diff lock on the centre diff for true 4WD, apart from that as Mick stated they distributed power to both ends as required and the Fergusson system is even more complex as used in the Jensen Interceptor.
The one plus with full time 4 is the superb handling on road in any conditions, I cruise through roundabouts in the wet with no hint of slide while the hoons try to keep up in the hotted up Commodores etc and fishtail through, you just get used to not having the beast break away, the negatives are the fuel economy (or lack of 24l per 100km) and front tyre wear, but, as I regularly tow 3 tonnes I wouldn't go any other way.

[journeyman Mick]

Years ago I used to drive an old international 4x4 truck. It used to get some form of transmission wind up even when used off road (which it was quite often). Used to have to drive it back and forth for about five to ten minutes trying to get the transfer case back into 2 x 4 .

Mick