Suzuki Jimny

bazzjazz

I have just purchased a 2002 low mileage (23k) Jimny (€3k, I think I got a good deal) but I have a very hazy understanding of 4x4's and would like to clear up a few questions! Hopefully you more knowledgeable people can help me!

When can\can't I engage 4 wheel drive?

My understanding is there is no centre differential and therefore I can't use 4 wheel drive on the road. What exactly is centre diff? Is it to do with wheels needing to turn at different speeds when turning?

Can I use 4 wheel drive in snowy/icy conditions such as we have had recently?

What damage can I do using 4 wheel drive incorrectly?

Apologies for what are probably basic questions and thanks in advance for any advice!

peasant

When can\can't I engage 4 wheel drive?
can: anywhre that's slippery ...wet grass, muddy field, gravel road, very wet tarmac
can't: anywhere that's grippy ...i.e. dry tarmac


My understanding is there is no centre differential and therefore I can't use 4 wheel drive on the road. What exactly is centre diff? Is it to do with wheels needing to turn at different speeds when turning?
Yes
going round a bend, all four wheels need to go at different speeds. The axle differential evens out speeds on one axle, the centre diff does the same for front and rear.
Without a centre diff you eventually get transmission windup, at full steering lock this will happen within a few turns of the wheel

Can I use 4 wheel drive in snowy/icy conditions such as we have had recently?
yes

What damage can I do using 4 wheel drive incorrectly?
best case scenario (at low speed): the engine stalls
worst case: something very expensive breaks

CJhaughey

This site explains things quite well.
http://rubicon-trail.com/4WD101/4WD-AWD-autoAWD.html

bazzjazz

Perfect! All is clear now, thanks for clearing things up for me.

peasant

and don't forget ...you can still get stuck pretty easily.

Get one front and one rear tyre into a situation where they have no traction (be it by trying to climb over something and coming to the end of axle articulation or simply by parking one side of the vehicle on ice/ sinking it in mud) and you're going nowhere, as the Jimny has no locking differentials on the axles.

bazzjazz

Ok, I'll bear that in mind!

Vegeta

here's a good explanation of it

Transmission wind up, is caused by the front and rear wheels traveling at different speeds round corners. This is because the outer wheel is traveling round a larger circle than the inner wheel, so the outer wheel actually goes round more and travels a greater distance than the inner wheel.
The differentials, one in each axle, share out the power to the wheels, so that the outer wheels when turning a circle can rotate faster than the inner wheels. All cars have differentials otherwise the car would not be able to turn a corner very well. One wheel would always be dragged round rather than pushing the car round. On a four wheel drive car these differentials are still permanently attached to the engine at one point. The front pair of wheels are also traveling at a different speed to the rear wheels, when traveling round corners. This can mean that the drive shafts, which at one point are connected together, are traveling at different speeds, gears eventually mesh tightly and the drive axles twist. Sometimes a wheel will spin to release pressure, but on Tarmac with good grip this is unlikely and a drive shaft may break instead!

bazzjazz

That sounds like a very expensive error to make! Thanks for the detailed reply.

90% of the time I will not need 4 wheel drive but there are occasions when I am up the mountains that it will be handy, so it's good to understand when to use it correctly (now HOW to use it is a different matter ).

I did a bit of off-roading in one of these quite a few years ago in a quarry and was amazed at what it could soak up. I remember the instructor saying never use 1st gear, always start in 2nd and keep you foot off the clutch.