topls68
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• maywood, IL, USA |
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• Registered on 2/8/2009 |
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• 18 posts |
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 Posted:8/8/2009 15:27 |
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I have an 01 excursion limited. So I went on a trip and my excursion got stuck in mud. Mind you not high mud like if I was off roading or something. I switched the vehicle to 4wd hi using the selector and and 4wd displayed on the dash. I then tried to get out and couldn't. Front wheels would not spin. I thought I had the hubs in locked or something and got out to check but they weren't. Long story short I got pulled out. The next day just to see if I really had a problem I put four wheel drive on, heard it engage, drove for another block or two. then gunned it at a stop sign. I had been raining so I knew the rear tires would spin d the front wheel should pickup but it didn't. all the while my 4wd indicator light is on. Is it time to take my truck in for a checkup? |
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dnevins
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• Subscriber since 12/29/2009 |
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• San Diego, CA, USA |
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• Registered on 12/28/2009 |
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• 340 posts |
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That sounds like the front hubs aren't locking. With the dials in AUTO, these hubs are supposed to lock themselves with engine vacuum when you shift into 4WD. The transfer case can shift and the 4WD light can come on while the hubs stay unlocked, and then the front axle turns but the wheels just freewheel. That matches what you saw in the mud and at the stop sign.
Ford put out a service bulletin on exactly this, TSB 03-14-3, for 2000-2003 Excursions and Super Duty 4x4s whose front hubs won't engage or disengage properly. The cause it gives is restricted vacuum to the hubs, and the bulletin's repair is done at the front hubs themselves. Your '01 is in that range.
Here's a quick test before you pay anyone. Turn both hub dials by hand from AUTO to LOCK, put it in 4WD, and try it on wet grass or gravel. If the front pulls now, the transfer case and front axle are fine and the fault is on the vacuum side of the auto hubs. Owners commonly find a cracked or rotted vacuum line (one common spot is on the passenger side near the exhaust manifold, where the heat cracks it), a leaking hose connection, or a rusty hub that sticks.
Until it's fixed, lock the hubs by hand any time you think you'll need 4WD, and turn them back to AUTO when you're back on pavement.
To answer your question: if it pulls with the hubs locked, the fix is on the vacuum side. That could be a leaking line, which is cheap, or the bulletin repair, which means pulling both front hubs. Either way, the transfer case and front axle are fine. If it still won't pull with both hubs on LOCK, then yes, take it in, because the problem is in the transfer case, the front driveshaft or the front axle.
Dana
https://partslogic.com |
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