4WD Speed

This may seem like a daft question, but here we go:

Does anyone know what speed you can do in 4 wheel drive ? I have read several articles and they suggest that you can only really crawl in 4wd.

The problem we have is that our Jimny will go into 4 wd easily enought, but is difficult to get out of 4wd. I have read on other threads here, that if the car is rocked or moved forward then more often that not, you can select 2wd again.

As this is my wifes car, she wants to use 4wd around the snowy / icy sidestreets, but is worried that when she gets to the gritted main roads, then she will not be able to get our of 4WD.

The other question is it possible just to leave in 4WD for normal road journeys permanently

Cheers

Paul

No - don't drive on the roads in 4WD, you will wind up the transmission. At best it becomes impossible to get back into 2WD at worst you break something really expensive.

There are two types of 4WD systems (leaving aside odd technical variations), permanent and part-time.

Permanent systems, such as that fitted to most modern 4x4s like Range Rovers, including a central differential. This central differential allows the front wheels and rear wheels to rotate at different speeds, allowing all 4 wheels to be driven by the engine without stresses building up in the system.

Part-time 4WD, as fitted to the Jimny, does not have this central differential, therefore the front and rear wheels have to rotate at the same speed. This builds up stress in the system that is normally relieved by the wheels slipping on a rough surface (off-road). On road the wheels do not slip and stress builds up until something breaks.

Why do the front and rear wheels have to rotate at differenrt speeds?? Drive your car on a surface that "marks" turning a circle and look at the tracks you have left, the rear wheels have not follwed the same tracks as the front, they have travelled a difference path/distance therefore needed to rotate a a slightly different speed.

So do not use 4WD on a grippy surface

Martin

This has always has puzzled me as the manual as you can put it into 4x4 upto 60 mph.
I have left it in 4x4 for a long time (20 miles) by accident, after dealing with a very slippy wet section of road around here. Nothing bad happened apart from locking up when i was trying to reverse after parking.
But this was before i learnt about diff windup, so i tend to be more careful now days. Live and learn.

I regularlky slip it into 4WD when driving .. 40 mph or so just to make sure everything is working ./.. the light comes on and the hubs "Ping" into position. do a mile or so and thenslip it out again.

If were in heavy traffic I put it into low range and crawl, occasionally driving up to 4th before looking for an opportunity to stop and putit back in high range. Generally though, I always make sure teh wheels are straight as to avoid windup ... where possible

Jason

Excellent - Thanks for the advise.

I used 4WD in the aftermath of the latest snow fall, when the roads turned to ice - it certainly did the trick and we reached when others couldnt..

This had often confussed me I drove mine jimny about in the snow for ages in 4wd high some times up to 50. In low box I don't go to fast on the road unless it's slippery.

But now any again there is a flood near me it floods across the road and is about a mile long and I always drive that in low box as it's get about 3ft deep in places

I wouldn't worry too much ... we regularly run for 10 - 15 miles in Low ratio when green laning.
I always drop into 4L and use 1st / 2nd when fording water or driving through mud.
In snow, I quite frequently mess about with 4wd and 4wd, just to see how far I can get, but have driven 50 plus miles in snow in 4wd. Its just that extra Grip.

Indeed, I have spent all day and done over 100 miles in 4wd switching between High and Low where needed, but keeping the hubs engaged.

At the end of the day its what its there for. Just respect that the handling characteristics at speed may also change

Unless your doing Lock to lock turning, your not going to wind up your transmission.. All your going to do is increase your fuel useage, add extra wear and tear to your low ratio's in the transfer box.

Ours is an auto so when switching to and from 4WD I've either been at a standstill and in neutral or no more than walking pace and with the throttle backed off and just applied enough pressure to let the lever slide into position easily, never forced. If it were an manual I'd dip the clutch to reduce any stresses.
Most we've been up to is mid 30s as if the conditions are bad enough to warrant 4WD then anything more isn't much of a priority. Does give a great sense of more control and ability in 4WD over this recently interesting winter and allows you to concentrate more on the hazards. The snow and ice didn't faze it one bit, absolutely love it!