Hey, here's a good one I just found:
I have an F250, 5.4l motor, 4x4. and while driving today, with the hubs in 'auto', the 4 wheel would just cut out and go to 2 wheel for no reason. The switch on the dash stayed at the 4 wheel position, but it would just go into
2 wheel. I noticed it after during a turn, left or right - didn't matter. Sometimes just going straight. It will go back to 4 wheel if I turn the switch to 2 then back to 4...Anyone run across this?
First, are your certain you are losing 4wd? What is the truck's behavior that makes you suspect a 4wd problem?
When you are turning, are you turning on hard, dry pavement, or slick snow? Do not use 4wd on dry pavement or any other hi-traction surface...you will destroy something.
Assuming you are not using 4wd on high-traction surfaces and your T case is funtioning properly (the dash light is controlled by the T case) , it sounds like one of your front hubs might be disengaging on their own, or not engaging at all.
Your F250 is a '98-up Superduty, correct? The hubs are vacuum-actuated, and are prone to failing. You can reach for the axle U joint at each front steering knuckle and see if it can be turned by hand. It should be locked in
4wd, and free in 2wd...you should be able to turn it when it's in 2wd. If your hubs aren't locking when they should, you can manually lock the hubs (both of them) by turning the hub dials from "Auto" to "Lock." You can drive around in 2wd with the hubs locked, you might see a slight decrease in gas mileage, but you might not notice it since these trucks get abysmal mileage anyway.Asuming it's a hub problem, if it's still under warranty, have it repaired, which usually involves replacing the hub locks. If not under warranty, the dealer isn't cheap to do this.When my auto hubs finally go I am going to replace them with manual hubs, a few others in this forum already have done so.
good luck
OK. forgot the other details.
Driving on snow covered roads. When I turn a corner, the rear end breaks out. It would not do this if 4wd was still engaged. I can also feel it drop out if I am looking for it. I will try to see what it does if I turn the hubs to 'lock'. At least i will have some more info to tell the shop. Yes, I have the ext warranty from Ford - covers the drivetrain.
My guess is that vacuum actuated hubs are starting to fail. As already mentioned, a common problem. The usual problem is the seals in the hub. Turning the hubs to lock will verify it is a hub problem and not a t-case problem.
Matt
99 V-10 Super Duty, Super Cab 4x4Dropped it off to the truck fixer place today. They think the same thing.
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