H4 in rain or not?

Seriously? If you need 4wd in the rain take the bus, you shouldn't be on the road.

 

Fify

 

I had no idea the manual recommends 4wd regularly. Unless it snows I only use 4WD to get down the hill and behind my house every few months. A grand totaly of about 90 seconds up and back.

 

If you don't use the 4X4 system for extended periods of time the internal parts do not get lubricated. Sooner or later when you turn the dial to 4X4, it won't shift into 4X4. I had to tow an older 4X4 F250 and a stock trailer up a hill in the Utah desert in May. The truck hadn't been used in 4X4 for months and when it was needed to pull the trailer up a steep gravel covered hill it wouldn't shift into 4X4 and couldn't get enough traction in 4X2.

But DO NOT do so on wet pavement. It probably wouldn't hurt for short distances as long as you aren't doing any cornering. I find myself on a gravel or dirt road at least once every few weeks. I always shift into 4X4 for a mile or so every time and even stop and go into 4lo at least once every 2 months for a short distance. I don't need it, but the truck needs it.

As for driving in rain in 4X4. You aren't gaining any extra traction and are in fact getting worse traction than you would if you left it in 4X2. With open diff's and in 4X2 all 4 wheels can freely corner at different speeds. If you lock the diff, or operate in 4X4 then the inside wheels in a curve MUST slip on the pavement. There is no way to avoid it and it isn't something you want to do at highway speeds.

If you have AWD it is different. It will send power to all 4 wheels and still allow each of them to turn at different speeds.

 

I live in Washington, I'd never disengage 4wd if I turned it on every time it rained.


No, use proper throttle control and you'll be good

 

Never

 

I've gone through snowy mountain passes (snow on road) in RWD and been just fine. It's all how you drive... and how much weight you have in the bed to help with traction.... and your tires..... Point is that you shouldn't need 4WD in the rain. If you were crawling through snowy roads, sure, but rain?

 

Shoot over to the NJ bs thread

 

Nothing in the manual says any thing about "dry" dirt,snow etc. just 10 miles or more every month.

 

You do realize that the CV's turn all the time 4WD or not?

 

Of course. However, when 4lo or 4hi is engaged and you make a turn, the distance travelled by your front wheels differs from the distance travelled by your back wheels. Your transfer case doesn't have the ability to compensate for this and binds, as we do not have a "center diff" the way AWD vehicles do. This binding has adverse effects on the life of your cvs as it loads them up in a big way UNLESS you're in a low traction situation, because then the wheel causing the binding is allowed to slip and unload the system. Your knees are constantly working as you walk, but should provide you with a lifetime of service. That is not the case is you try to walk your whole life carrying 500lbs on your back. (Under load)

 

Maybe you just over looked it... in my manual it's covered on the page prior to where it says to engage 4WD for at least 10 miles each month. I assume they didn't feel they needed to explain again what road surface to do those 10 miles on because they had just got done explaining it a few paragraphs back.

Page 179 (of my manual) under Four wheel drive system...
H2- use this for normal driving on dry hard surfaced roads.
H4- use when you experience loss of traction.

Page 304... under Tips for driving in various conditions...
"Four wheel drive models- Toyota recommends not using four wheel drive on dry-hard surfaced roads."

From Toyotas four wheel drive systems website...
"Drivetrain Binding on Dry Pavement... The way a part-time 4wd system is designed both front and rear axles rotate at the same speed when 4wd mode is engaged. This splits power at 50% front and 50% rear. On dry pavement this will cause the drivetrain to bind when vehicle is attempting any type of turn. Drivetrain binding causes severe strain on various 4wd drive components. Therefore 4wd mode on these vehicles should only be engaged in slippery conditions such as off road driving and poor road conditions."

From Toyota four wheel drive system explained (Tacoma HQ)...
The Tacoma – like a lot of pickup trucks – uses a part-time 4WD system. The front differential locks, which means that the Tacoma’s 4WD system should only be used on surfaces with limited traction. Using the Tacoma’s 4WD system on dry pavement should be avoided, especially if you plan on taking any turns.

From 4X4abc.COM (see below links)...
The terms used differ from driveline wind up to axle bind, axle wind up and drive line bind, but fact is, that you can not use part time 4WD on dry high traction surfaces. Period. You'll get drive line windup. This has been known since the invention of 4WD more than 100 years ago.

additional info...
http://www.ttguide.net/four_wheel_drive_system-68.html

 

HaHa used mined yesterday and most weekends going to quarry. Had to go to the top was at bottom getting 1 ton of rip rap.

 

If you need 4wd in rain I would think you need new tires perhaps. I use my 4wd at least once a week when I go off the road to cut firewood or just take some trails that have steep Hills or mud hole in the valleys.

 

Ya know if you feel your drive line can't take the strain you should have bought a Humv the drive line is far stronger than the tires traction. Lighting the rear wheels up on drive pavement is far more
destructive than using 4wd on the pavement ( I did a thesis on this in 1964 using a super 8 movie camera the rear springs assumed a "S" pattern). There is no radius on a public road that is great enough to bind a 4WD parking lots yes but the tires will slip long before you damage any thing. My 97 had close to 300 grand on it, in the winter I never took it out unless I was parking only because it made it easier my commute was 100 miles round trip it made it to the bone yard with all drive line intact except for the rear U joint. In the winter in Maine it's all ways slick if it isn't snow it's ice.

 

^^ This ^^

 

Use should always use your headlights in the rain, it's the law. Doesn't matter if you use H4 or 9003 bulbs.

 

I get sideways in 2x4 in the rain pinning it. No need to engage 4x4.

 

But you should use 4 low on a rainy road. ... Not 4 high.

 

Help me understand how our CV's will wear quicker just by using 4H in the rain? I can see causing stress on them if you're in 4H on dry pavement making hard turns, but on wet roads with minimal turns what added wear is taking place? I only ask because they spin all of the time, regardless of whether you're in 2H, 4H or 4L. Am I missing something?