Grinding noise in front in 4x4 01

[Jerry Falkiner]

I have just over 150,000 miles (250k kms) on my 01 Job 2. I haven't used the 4x4 all summer (abnormal for me), and just turned it on during some rain/snow on Sunday.



It took a minite to kick in, even though the light turned on immediately. I was moving at about 40 km/h, and had my foot off the gas.



It sounded like metal on metal in the front, and HORRIBLE. I was afraid to run it for very long, so I turned it back off and it took a while to go off again. I tried it again with the same result.



I am guessing I need an oil change in the front diff, but am not sure. Any ideas?

 

[Andy Chase]

Could be the front U-joints as well. Depending on the U-joints you have, you might be able to re-grease them, otherwise replace w/ new ones. Fairly cheap project if your handy.

 

[Jerry Falkiner]

Why would the U-joints only make noise in 4x4 high? Wouldn't they be noisy all the time?



Not trying to pick, more to understand.

 

[Andy Chase]

I'm guessing your saying as opposed to just using 2wd, it would be because the front driveshaft isn't turning. I had similar sounds to this on my F-150 and 9/10 times it was the U-joints, the other time it was my hubs. U-joints would be the cheaper fix. If you can, look at the front U-joints and see if there is a nipple on each one to pump some grease into it, kinda like on a bearing buddy of a trailer.

 

[Johnny O]

The hubs are always locked in and the front end and driveshaft turn all the time although no power is sent to it from the t-case when you are in 2wd. Check the lube levels in the front diff and t-case, although I suspect the noise is either a U-joint or wheel bearing. It's hard to say without seeing it.

 

[Dre L]

The front driveshaft is turning all the time. I had that horrible grinding noise one day in the rain while slowing down in 4x4, then it went away, but left a roaring noise / vibration in the front whenever I was in 4High, letting off the gas and slowing down under 30MPH. This is the only time the vibration would happen.



I would notice that if I was driving in the fast lane 2WD by a divider with the window down, I had a chain rattle which I could only describe as a chain with slack being slid over a smooth pulley.



I made several trips to Ford and had them check the entire 4x4 system. I specifically asked them to check the front driveshaft, u-joints, differential, transfer case, etc... they said nothing was wrong, everything checked out fine.



A year later in 2WD on a road trip, the most horrific crunch noise happened on the highway. Got towed, U-Joint blew and took out the front shaft. Local Ford dealer installed a new joint and used shaft (only part available) and I was back on the road. Roaring vibration and chain rattle sound were gone after that, but so was $300 in repairs. I'm guessing that if they're on their way out, they only make noise under load in 4x4 until they finally just fail.



u-joints are like $10. You could probably have your shafts cleaned, balanced, and re-jointed for under $100. I'm still trying to find a good place for this.



Hell, I'm still trying to find a place willing to do a front end rebuild. I don't get mechanics around here. You ask them to do stuff, and they say "nah, everything's fine." Business must be great that you can turn down major jobs.