Front end CLUNKING Helppp!!!!
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Front end CLUNKING Helppp!!!!
2002 F250, 8 inch lift w/ 37's
Manual locking hubs
Ok so my truck has no issues in 2wd even with hubs both locked or when in 4x4 hi/ low with hubs UNLOCKED.
BUT as soon has 4x4 system is in action as I idle forward there's a massive clunking and binding sound like a sledge hammer bouncing off my front diff./ drive shaft. But there's no physical binding of any components that I can see! Just a rhythmic and consistent thumping.
When you turn the wheel either direction the sound intensifies.
I even dangled from the side steps as my buddy rolled forward to observe the situation.
Manual locking hubs
Ok so my truck has no issues in 2wd even with hubs both locked or when in 4x4 hi/ low with hubs UNLOCKED.
BUT as soon has 4x4 system is in action as I idle forward there's a massive clunking and binding sound like a sledge hammer bouncing off my front diff./ drive shaft. But there's no physical binding of any components that I can see! Just a rhythmic and consistent thumping.
When you turn the wheel either direction the sound intensifies.
I even dangled from the side steps as my buddy rolled forward to observe the situation.
Fleet Mechanic
Joined: Jul 2005
Posts: 1,800
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From: Southern Colorado
Try removing the front driveshaft and leave the hubs locked and see if it's still there. If it's worse when you're turning, that seems to point to the outer axle u-joints. Slightly binding u-joints can put up a lot more fuss under load.
Long shot: If your tires are different sizes (front to rear) or gears are different between the diffs, this could cause such a noise.
Has the truck always done this in 4WD or is this recent?
Long shot: If your tires are different sizes (front to rear) or gears are different between the diffs, this could cause such a noise.
Has the truck always done this in 4WD or is this recent?
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Trucks had it since I purchased the guy selling it on craigslist was apparently "shocked" at the noise aswell cause not that long ago he used it with no problems
This was before putting brand new rear tires, due to punctured side wall
I feel like bad axle U joints has possibly been removed from the list of potential problems, I removed both axles and serviced the front diff I replacing the axle bearing inside the hub (that one little part you can actually change in the non-serviceable hub)and the outer hub seal, you know that big one that's inside the knuckle with a little bearing in it. and also did the axle dust seal. The U joints seemed fine, had them in the vice grip looking for unnecessary play. But they seemed smooth.
Buttt what you said about tire size difference kinda puts up a potential red flag my front tread is pushing on being maybe 5/16 lower on each chunk of tread (so a total size difference of 5/8 maximum) then account for lower front tire pressure and more load.on front tires?? Could this difference in diameter/ circumference be enough???
This was before putting brand new rear tires, due to punctured side wall
I feel like bad axle U joints has possibly been removed from the list of potential problems, I removed both axles and serviced the front diff I replacing the axle bearing inside the hub (that one little part you can actually change in the non-serviceable hub)and the outer hub seal, you know that big one that's inside the knuckle with a little bearing in it. and also did the axle dust seal. The U joints seemed fine, had them in the vice grip looking for unnecessary play. But they seemed smooth.
Buttt what you said about tire size difference kinda puts up a potential red flag my front tread is pushing on being maybe 5/16 lower on each chunk of tread (so a total size difference of 5/8 maximum) then account for lower front tire pressure and more load.on front tires?? Could this difference in diameter/ circumference be enough???
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An additional note, the consistent beat of this sound is not in sync with the revolutions of the axle U joints it's in sync with revolution of components before the differential.
Please anyone with bright ideas pitch in I really can't be chasing problems and keep having my truck out of commission it's very important for work that she's up and running strong
not sitting on jack stands 
Please anyone with bright ideas pitch in I really can't be chasing problems and keep having my truck out of commission it's very important for work that she's up and running strong
not sitting on jack stands
Fleet Mechanic
Joined: Jul 2005
Posts: 1,800
Likes: 52
From: Southern Colorado
Sounds like you're ruling out axles...
Have you grabbed the front driveshaft where it goes into the xfer case and wiggled it up and down to see if your xfer case output bearing is shot? Also, have someone drive it 20' in 4x4 on pavement (when it's clunking) and you watch the front driveshaft (on your hands and knees, off to the side) to see if the shaft is jumping around. Transmission and driveline shop guys could go along for a quick test-ride, and give you their .02 worth, too. Usually, this is free.
Have you grabbed the front driveshaft where it goes into the xfer case and wiggled it up and down to see if your xfer case output bearing is shot? Also, have someone drive it 20' in 4x4 on pavement (when it's clunking) and you watch the front driveshaft (on your hands and knees, off to the side) to see if the shaft is jumping around. Transmission and driveline shop guys could go along for a quick test-ride, and give you their .02 worth, too. Usually, this is free.
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AndAndI'm on vacation and my trucks home right now but I'll be sure to check out the drive shaft into transfer case, how difficult to repair the transfer case bearing?
Also the front driveshaft gives off some pretty heavy vibration for every clunk, I rested my hand on it as it spun around... AndAnd it seems to be strait no visible hoping but i should probably put a strait edge to it
What do you think about the tires though? And also i should mention all these problems were discovered and tested on asphalt, t
Also the front driveshaft gives off some pretty heavy vibration for every clunk, I rested my hand on it as it spun around... AndAnd it seems to be strait no visible hoping but i should probably put a strait edge to it
What do you think about the tires though? And also i should mention all these problems were discovered and tested on asphalt, t
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