Jeffrey154

I'm new to 4x4's and I have a quick question about them that I havnt really seen an answer to.

I drive a 87 4x4 pickup. Is there anything wrong with keeping my hubs locked and the truck in 4 wheel drive for a long period of time and can I run the truck in 2 wheel drive with the hubs locked?

I'm really just wondering if this is a bad idea and what I can expect to see if i do.

thanks

RobD

A) You can run your truck in 4x4 as long as you want, provided you're on poor traction. Never run it on dry roads or anywhere where traction is good.

B) Leaving your hubs locked in while in 2wd won't harm anything right away, but will lead to premature wear and tear, so if you don't need them locked, unlock them.

93yotaSR5

what he said

Jeffrey154

thanks for the suggestion

RobD

And remember, 4WD doesn't give you better traction, it gives you better acceleration on low friction surfaces. You won't stop any shorter and turning is usually worse.

My favourite saying with regards to 4WD: four-wheel drive is good for getting you stuck deeper, farther away from home.

turkeykiller365

4 wheel drive does not mean 4 wheel stop

flyingbrass

It doesn't even mean 4 wheel drive. With open diffs, get a couple wheels in the air and you have no wheel drive.

toyota4x4907

A) exactly

B) which is a negligible amount, IMO. I keep my hubs locked from when it snows and/or gets icy (October usually) until April or May. Never had to change the CVs on any of my vehicles in 5 years, probably 80K-90K miles.

RobD

I would agree...but if you don't need to turn the CVs, then don't. My hubs have been locked for about a month now, mostly in 2WD.

toyota4x4907

I notice a significant increase in traction when braking on ice in 4wd vs 2wd. The rear end has less tendency to kick out in 4wd, both while driving and stopping. Not saying 4wd is the end all to stopping on ice. It isn't. My brakes still lock up (no ABS ) but you just need to know how to use it to your advantage

toyota4x4907

I just turned this thread into 4wd on ice vs 2wd on ice. sorry

RobD

It cannot increase traction while braking. Traction is a function of the tires gripping the road surface. Lowering your tire pressure can help give you traction, for example, but shifting into 4WD will not.

What you're probably noticing is that you're decelerating your front and rear axles at the same time, instead of the normally higher bias that is applied to your front brakes first, shifting the weight off your rear axle.

In essence, you're slowing down your drivetrain more evenly, and therefore, your tires.

ToyoTech559

keeping the front hubs locked lowers your MPG as well as wear and tear on the cv boots

Jeffrey154

thanks all!!!

pbiker11

If you use your gears to slow/stop then 4WD will help with braking. The front end is forced to be slowed down instead of just the rear axle because of the 4WD being locked in. Its not "braking" in the traditional sense, but it does help you slow down.

toyota4x4907

yes, so the front tires won't lock as easily, therefore keeping better traction. Spinning tire(s) have better traction than sliding tires, hence the use of ABS.

abecedarian

okay. I got it.

On ice or slippery surface, 4wd can help keep the rear tracking behind the front if you're slowing down, i.e. off the throttle, but not on the brakes, but braking in 4wd is better than braking in 2wd since the front wheels are locked to the rears through the drive-line / transfer case. Braking in 2wd means the front will lock first and slide before the rears do, which causes loss of control.

Did I miss anything?

toyota4x4907

To an extent.

ToyoTech559

rolling tires is a better word for it

RobD

Okay, I could get into a long-winded discussion about all of this, but I'm going to try and keep it shorter.

You have three types of traction: sliding, rolling, and static (stopped).

Sliding is worst, rolling is better, static is best. You need to keep your tires rolling while braking to stay out of a skid. Easing off the throttle in 4WD will decelerate the tires at roughly an even speed, allowing you to keep rolling traction. Applying the brakes in 4WD will help balance out some of your braking force through your drivetrain, whereas applying the brakes in 2WD can slow one set down faster than the other set, allowing your vehicle to go into a skid.

So, braking in 4WD does NOT mean you have more traction. Braking in 4WD balances the braking forces out. Skidding all 4 wheels, however, will put you into an unpredictable skid.

Traction is, and always shall be, a function of tires against road, regardless of where your transfer case is set.