[dp87]

Is it ok to put my jimny in 4H when driving on wet greasy roads?

I tried it tonight for about 10mins and the jimny handled much better around corners and round-abouts.

Normally on wet roads in 2H, turning thru a round-about it understeer, and then suddenly oversteers. And taking off at traffic lights the rear wheels spin easy.

I thought i would check with you guys before i try 4H again. To me it seemed much safer.

I didnt notice anything abnormal about the car. How would i know if the transmission was wound up?

cheers, Dan

[Gwagensteve]

Don't do it. You'll know when the transmission has wound up when the transfer case breaks. I could bang on about all the circumstances and details forever, but long story short, your car isn't designed to be driven on paved surfaces in 4h, wet or dry.

Personally I don't like the feel of a car in locked 4h or a constant 4wd car on road, and almost never use 4h except on snow, but each to their own. Doesn't change the mechanics though- it will break your car.

[Abraxix]

I would not shift into 4H on sealed roads in the wet no. just a no no, as above you'll know when it's wound up. you'll hear a lovely sound

but I'm going to be like the others here for one on a forum...

slow the hell down, if you're under steering into a round about just cuz it's raining in a jimmy... slow the dong down I don't want you crashing into me or my family because of your own incompetence.. same with when you're taking off... don't drop your clutch and learn to drive smoother....

if your jimmy is spinning wheels and you're under steering and over steering at all and a police officer saw you they'll say the same thing but they will give you a fine, I had a 100HP 2 door rear wheel drive vitara on bald tires in the rain I was fine. then I replaced the tires and I was STILL fine..
there should be no difference except I was driving smarter and not fast to spin around...

[Gwagensteve]

WTF? Moralising much?

Because the op has mentioned noticeable understeer or oversteer on wet roads in a car with inherently low traction and a high COG doesn't mean they are a threat to you or your family. Pull your head in, that wasn't called for. That attitude is half the reason we are in such a confused mess over what constitutes "road safety."

Personally I'm much happier knowing a driver a) understands what's going on when they are driving their car and b) is interested in trying to improve it. Someone shouting them down because they've noticed their cars inherent handling balance isn't helping anything.

Apparently though, driving a SWB vitara with bald tyres around is "fine" so long as you drive slowly. How did you "discover" this?
Personally, I think swb vitaras have deeply troubling handling and if I was in government they would have been prevented from sale in this country but bravo, sir, to you for not spinning one backwards off the road wih your bald tyres.

[shep]

It's called driving to the conditions, simple concept.

[Gwagensteve]

That's not really what old mate here is saying though- someone who drives their car into understeer or oversteer is still driving "to the conditions" as much as someone who doesn't exceed the lateral grip of their tyres, however, that doesn't mean driving the car into understeer or oversteer is safe in all situations, no different than driving at the speed limit isnt safe in all situations. The op didn't ask to be attacked for their decision making ability. It was a technical question and didn't require a moral answer.

[alien]

What pressure are your tyres at? This makes a HUGE difference in the wet... as does the tread pattern of course.

[klutched]

Is it different for a GV? Next to the transfer lever it says what it can be used for in the different conditions. I believe it says it's ok to drive in 4h on wet roads. Will check when I get home.

[Gwagensteve]

It's not different, regardless of what the description is next to the lever. Only vehicles equipped with a centre differential can be used on paved roads in 4wd, like a ngv.
In fact, because of the bind using a part time 4wd system on a paved surface causes, I'd argue the car is less predictable. On something like a long sweeping corner you'll feel the car move about as bind builds and releases- similar to driving with an auto locker.

[droverdave]

If your wheel alignment is out considerably it may have an effect on how easy it over and under steers, and these issues may be exaggerated in low traction conditions where the tyres will slip easier. long shot, but worth mentioning i suppose.

[henno]

I am fine with predictable understeer; I am fine with predictable oversteer. However, easily the scariest cars to drive are those with initial understeer that unpredictably transfers into a snapping oversteer. No thanks!

[tanshi]

henno wrote:

I am fine with predictable understeer; I am fine with predictable oversteer. However, easily the scariest cars to drive are those with initial understeer that unpredictably transfers into a snapping oversteer. No thanks!

haha you say that but our race jeep drives like that all the time.

you hook it full lock and keep going dead straight, then it turns and the ass hangs out and you have to fight it to get it back in.

BEst fun ever!!!

[henno]

I guess in my experience it has always been in shitty front wheel drive "passenger cars" with poor chassis/suspension design. I have driven some fast cars in my time, but nothing scares me more than the rear end of a FWD car trying to become the front end half way through a roundabout.

[alien]

^^ I had this driving a Corolla in New Zealand. On the Mountain Passes on hairpin turns you HAD to handbrake around the corner. If you didnt do a little handbrakey the Corolla would try to understeer you into the guardrail, and if you backed off the accelerator during that understeer you'd get instant oversteer landing you facing the wrong way on the road. Pulling the handbrake on the initial turn kept the back tracking (all be it sliding) with the front and allowed you to drive the corner in the left lane.

It was great fun, because you were in constant fear for your life - but definitely not something i'd want to drive all the time! Thing is, it also had bald tyres (Thanks Avis) so that won't have helped at all.

[dp87]

ok thanks for your advice. I wont be using 4H again on wet roads, if its not healthy for the driveline.

Like i said, i only used it for about 10mins purely as an experiment to test the handling characteristics of 4H.

I will continue to drive in the wet in 2H, which isnt a problem. The understeer and oversteer is predictable .
99% of the time i do take it easy in the rain. I know the jimny isnt a drift car!

I think most of the poor traction in the wet comes from having 30inch muds on (running 23psi).
When i have used normal road tyres on the jimny, there is a massive improvement in traction as you would expect

[alien]

Try dropping the rear a bit more... i run my 31s at 22psi rear and 24psi front in winter on the sierra. Also - are you running a front bar? Perhaps your front springs are a bit too soft, which won't be helping the understeer issue as the nose dives into the corner?

[dp87]

Ive got no front bar.

And tough dog suspension lift that is way too stiff unless i'm carrying a load or towing.

The understeering isnt that bad, its very predictable and only occurs when pushed around a sharp round about

[Marko_SJ]

How many race drivers here push their cars on the track?

I agree with Shep.

OP thats how such a car is likely to handle.

[Scrawny]

I've driven many Hiluxes in the wet and had to hook 4wd just get get off from the lights. I now drive a full time 4wd and get bad front wheel spin and chronic under steer. You get a feel for the car and know when to push and when to back off

[fordem]

Scrawn wrote:

I now drive a full time 4wd and get bad front wheel spin and chronic under steer.

I'm inclined to say that's NOT full time 4WD - it may be AWD but it's the crappy type that defaults to FWD and then feeds torque to the rear if it detects slip - one example is the Nissan Xtrail.

[magnat]

The only time I have ever used 4x4 on a paved surface was when pulling out from a boat ramp after the back end was in the water.. Even then once cleared of the slime covered surface it was out of 4H and back into 2WD...

[Scrawny]

fordem wrote:

Scrawn wrote:

I now drive a full time 4wd and get bad front wheel spin and chronic under steer.

I'm inclined to say that's NOT full time 4WD - it may be AWD but it's the crappy type that defaults to FWD and then feeds torque to the rear if it detects slip - one example is the Nissan Xtrail.

Nope, definitely full time 4wd

[Gwagensteve]

Yep. I've experienced front inside wheel spin is 80series cruisers and my Defender.
IMHO chronic understeer is a by product of high cog and high front roll stiffness. It's one of the reasons I prefer 4wd's without a front sway bar- more weight transfer on turn in= more front end bite.

Steve.

[fordem]

Scrawn wrote:

Nope, definitely full time 4wd

What vehicle? Look under the hood - transverse engine?

No AWD with any sort of fixed torque distribution should spin one end before the other

[JrZook]

fordem wrote:

No AWD with any sort of fixed torque distribution should spin one end before the other

??

Landrovers, Landcruiser 80 series etc have open center diffs for constant 4WD. You feed it the beans through a corner, the inner front will have the least weight transfer, thus the least traction and light up. T

[droverdave]

yerp, path of less resistance.

[Jezza86]

JrZook wrote:

fordem wrote:

No AWD with any sort of fixed torque distribution should spin one end before the other

??

Landrovers, Landcruiser 80 series etc have open center diffs for constant 4WD. You feed it the beans through a corner, the inner front will have the least weight transfer, thus the least traction and light up. T

depends how much weight is in the back. those engines are quite heavy. my mates prado (AWD) would oversteer on corrugations before understeering, unless you had a boot full of camping gear and the water tank full..

[Seth2013]

centre diffs are interesting, a subie with manual gearbox for example is a viscous coupling style LSD that is a constant 50/50 split but capable of 90/10 both ways. so like all LSD's they do have conditions under which the lock and other where they don't lock. I own a liberty and when doing donuts on a mud pan you get some interesting feelings as the power moves around.

I put my jimny in 4x4 once on a long straight very very wet piece of road (after I almost ditched because aquaplane at 50kph), but first sign of a corner - immediate disengage. nothing broke but I've never done it since.

[Gwagensteve]

Subaru and their variable torque split can f right off. My 2005 STi was the worst car I have ever driven on dirt because the centre diff was all over the place like a mad woman's breakfast.

Never confuse grip wih handling. Constant 4wd wrecks a cars inherent handling balance at the expense of grip.

[Seth2013]

I've heard this from a few people who've owned the STI's - glad I can't afford one

I once heard it explained that AWD cars have more traction, not better grip or handling.