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4x4 question

Discussion in 'Commercial Snow Removal' started by gntbik, Dec 31, 2004.

  1. gntbik

    gntbik Junior Member
    from ny
    Messages: 7

    i have an 1985 dodge truck and i was hering a noise when i put it in 4x4 so i changed the uv joint and then i was reading in the manual and it says not to drive it on hard surfaces in 4x4 why is that?????? i dont understand what if i need to have 4x4 on while im on the pavment what should i do cause it makes alot of nosie on pavment. im new to 4x4 trucks i dont understand why i have a 4x4 truck and it says not to drive it on the rode. anyone have any info for me.
  2. Rainman

    Rainman Junior Member
    Messages: 21

    It means don't drive it on hard dry surfaces. The road should be covered by snow or at the very least be wet. It is not recommended to use the 4 wheel drive unless there is some slippage available to the tires. Without slippage the transfercase has a tendancy to bind and may cause failure or total destruction of the case. SO DON"T USE 4 WHEEL DRIVE UNLESS YOU are on mud ,ice, snow or a wet surface!
  3. cja1987

    cja1987 PlowSite.com Addict
    Messages: 1,407

    Basically in 4X4 the front and rear axles are forced to turn at the same speed. Unless the wheels are slipping, you will feel a binding force when turning on dry surfaces. The transfer case will power the front and rear drive shafts with same rpm and is not able to satisfy the front axle's need for more rpm, your front wheels are forced by good traction to rotate faster than the rear but both are being powered by the same RPM causing a "bind".

    Not the best explaination, its complicated, but use 4X4 on snow otherwise stay in 2WD. You have to turn a little differently even in snow to avoid binding.
  4. Mebes

    Mebes Senior Member
    Messages: 386

    Here's the problem when you drive in 4WD.

    Any time you turn the outside wheel needs to turn faster than the inside wheel. (it has to cover more ground to go the same distance)

    Your main (rear) axle has a planetary gear set to allow for this.
    Because it is designed for this you get the "one wheel wonder", this is what causes the 1 wheel to spin in the rear.

    Now you lock in to 4WD because you need traction, so if the front axle had the same setup as the rear then you would only have 1 rear and 1 front locked together.

    So in order to get the best possible traction in 4WD, the front wheels are more or less locked together when in 4WD so in effect you get 3WD (2 front 1 rear)

    In bad conditions all 3 wheels spin together to help you and attain the best traction.

    In good conditions all 3 wheels have to go the same speed around corners (which is impossible) on dry pavement fighting each other to get around.

    In short... It is ok to be in 4WD as long as you go straight, but if you have to turn then you need to have a front axle that is designed the same as the rear (like on a full time 4WD model) which you don't have according to your manual.

    It's kinda hard to explain.
    Let me know if you have more questions.

    P.S. If your 4WD makes noise on wet or snowy pavement, going straight you may still have a problem.