Yep, I'm a newb to this forum but have a quick question...

I decided do some "googling" around 4WD to understand why I get so much binding when I drive in 4X4 with the wheel turned. I found an interesting web site (see Link) which described the difference between part time 4WD and full time 4WD.
After reading this I was interested in what system I have on my F150. The site doesn't have a lot to say that's positive about part time 4WD. Does anybody know what our trucks have? Are there any advantages to that type of set-up?

 

It is 4wd, I think the Harley's have AWD. AWD have something in them that allows them to prevent binding. Welcome to the forum.

 

Sorry, I know I have 4WD. My question is whether it is full time or part time. My understanding is that full-time 4WD is different than AWD in that you have a low range feature with the former. Also AWD has no competence on rough terrain since it was designed more for stability not hard work.

 

Ford uses a part time 4 wheel drive system on the F150. You need to manually select 4HI and 2HI.

 

AWD systems utilize a viscous coupling to transfer power from one axle to the other which allows you to run the "4wd" all the time with no binding

Our trucks are selectable and you should ONLY use the 4x4 on surfaces where the tires can slip because there is no viscous coupling in a 4wd system like our trucks have.

 

TRANSFER CASE SPECIFICATIONS

• Make and Model Warner 44-06
• Type 2-Speed Planetary Gears
• Lubricant Capacity (qt.) 2.0
• Gear Ratio — High 1.00:1
• Gear Ratio — Low 2.64:1
• Case Material Aluminum
• Part-time 4WD

 

Agree 4x4 locks it up
Only Harley and the new Limited trucks are AWD

 

Thanks All!
Now, how hard is it to convert to full-time 4WD? It seems like a more versatile set-up than part time. Is there a reason that Ford selected part-time? Cost? With all the warnings about not driving it on dry pavement, I can't imagine they chose it for it's durability.

 

Part time 4wd = True 4wd (a truck that you can shift from 2wd to 4wd) good for off roading
full time 4wd= all wheel drive (like the harley and many of cars) not good for offroading just good for handling

 

The only advantage to an AWD system is it helps you get moving on slick surfaces and it helps maintain control during emergency maneuvers. The PCM monitors wheel speed and is constantly transferring power from the wheels that are losing traction to the ones that have traction. This makes it useless for offroading or driving through deep snow.

True 4x4 uses a transfer case that, when engaged, locks the front and rear axles together and drives all 4 wheels at the same speed regardless of road conditions. The front wheels bind when turning on a dry surface because the diff isn't designed to allow different wheel speeds at the angles the front wheels can be turned. There's no binding at the rear diff because the wheels follow a much wider path when turning.

 

Why would you want all time 4wd. It just increases the amount of things spinning down the road. This will decrease your gas mileage.

 

Not really, most AWD vehicles are primarily front wheel drive until the front wheels start to slip. This is when the PCM directs power to the rear wheels, or any combination, to get the vehicle moving. Once you get going then it goes back to front wheel drive. This is how the auto 4 systems work as well, except they are mostly rear drive. The major difference is the auto 4 systems are true 4x4 when they engage and then go back to rear drive once your moving.

 

First, nice freakin GT500............


Second, just how serious is this "dont drive 4x4 on dry ground" issue?
I mean it snowed here recently and I just threw it in 4x4 and left it until it melted. But in the mean time the roads had been plowed in certain section and there were areas where the tires had worn down the snows but it was still in the center, and sides of the lanes.

Will that cause harm to the 4x4 since it wasnt 100% ice the whole time? Are we talking insta-failure with dry pavement? Do we have to turn it off on the dry sections then back on 50ft later on the snow?

Just want to make sure.. I didnt get a owners manual, and only know what I read here. I know nothing about 4x4........ but plenty about AWD, FWD, RWD.

 

moltenice, your 4x4 is fine. if you drove it through a dry summer on pavement the whole time you would probebly have some issues. but not for a week or so with some snow.

and you can have full time 4wd with a selectable transfer case. the "full time" refers to the front wheels. they always receive power when the "full time" is selected. when you have the "part time" selected when the wheels start slipping it sends power to the front wheels. this is the concept with jeeps. dont know if the same applies with fords

there is no big benefit to having fulltime over part time unless you plan on doing some serious rock crawling or bogging. then you might as well put full lockers and an atlas transfer case.

 

You can use 4HI on straight stretches with no issues. The problem is when making tight turns on dry pavement. This will cause binding and eventually damage to the transfer case or front diff.