I did a couple searches on creepy drivetrain sounds and haven't really found what sounds like my specific problem.

So in summary, I have the ol 97 f250 4x4 with a ZF5, driving along last weekend, went up a pretty decent bridge and while coasting down I heard this light clanging/rattling/grinding sound coming from somewhere beneath my feet, possibly trans/t-case area that was different from the regular chatter of the dual disk clutch. I paid closer attention and this noise only occurs above the 30mph mark, durring acceleration or coasting or braking until below 30. Pushing the clutch doesn't have any effect either, just speed.

Curiosly it stops when in 4wd. Every thing sounds like normal. Just gets loud and irritiating in 2wd above 30mph. Noise has gotten a little louder since I first noticed.

Any ideas where I should be looking? I have added fluid to the transmission and no difference. I'm leaning towards the t-case having an issue but not sure what to look for...

 

Automatic or manual hubs? What does it do when the transfer case is in neutral?

 

I just went through this. I found the drivers side manifold was ever so lightly rubbing in certain conditions.I grabbed a crow bar and pushed the firewall a little here and there. Now its gone. I think the engine mounts are just getting old but they don't look bad. Also i found a lose bolt between the oil pan and the frame member under it. most likely a rubbing noise.

 

Auto locking hubs. I haven't tried it with the t-case in neutral, would that isolate the front hubs and would I have to do that while coasting?

 

Did putting it in 4wd change the noise before you made adjustments?

 

And I just want to say point +1 for the Ford team, someone always has input or suggestions or something on here and it's quick.

I have a "friend" who bought a dodge and every time he asks questions on any one of the cummins forums it stays quiet for days until someone throws in a big shoulder shrug.

 

Pull the front driveshaft out.

That'll tell you if the noise is coming from the driveshaft itself.

 

Dropped the front driveshaft yesterday afternoon and the noise seems to have quit. I inspected the driveshafts and there are no real signs of wear, i will be replacing the upper U-joint as it was pretty stuck to the yoke and the caps ended up flying off, pins went everywhere.

But i did drive it around a good bit in 2wd and 4wd (without driveshaft) and that nuts&bolts-rolling-on-a-steel-plate sound seems to have gone away.

I checked fluid in the transfer case and it was actually full above the fill plug, like I didn't even remove the plug all the way because of the amount that was already trying to come out on the last few threads. I am assuming that this would happen by the trans. leaking into the transfer case? Could this cause that rattling sound if the fluid gets too low in the transmission?

 

Elaborate on "the needles just fell out".

If they all fell out id venture a guess and say there was no grease in the u joint cap. Where the needles rusty? Was there a bunch of rust colored dust in there?

I personally hate replacing the double cardian joint on those front driveshafts. I'll either send them out to my local napa to do it or find another driveshaft.

As for the tranfer case fluid level I wouldn't worry about that.

 

I tires 4x4 hi 4x4 low and many other things. The sound did not leave. but I think you figures it out. I just rebuilt everything before finding the rub spot behind the engine manifold.

 

[QUOTE=Kingkong0192;17343787]Elaborate on "the needles just fell out".

Nothing was rusty or worn, the cap on the upper ujoint just came off was at too easy, still had pins and some grease but a few pins were broken (1 or 2). Little bit of grease. Mine just has one regular old u-joint at each end, no cardain. But I don't like reusing ujoints after the cap falls in the dirt and half the pins scatter so for $20 I'll just replace it. It just seems odd that a slightly loose u-joint would make that much racket.

I turned the tcase over by hand when in neutral and didn't feel anything creepy or strange so I will agree the case is probably safe. Any votes for something rattling the flywheel? Because that's really kinda what it sounded like.

 

My apologies. I thought you had a 350. The 350s have the cardian joint in the shaft and the 250s have what you have.

I feel if the flywheel had an issue taking out the shaft wouldn't of fixed anything.

Id start with the u joints and put the shaft back in and go from there.

 

If pulling the driveshaft out fixed your problem then i would lend to the idea that it was your isssue. You will know for sure once you replace it

 

As it turns out, it was the front pinion bearing. After reinstalling the driveshaft with new upper u-joint I got to working everything around by hand and could turn the driveshaft about an 1/4 turn clockwise (looking at the front axle pinion) with zero resistance when the t-case was in neutral. Took the pinion nut off and could wobble it way too much. I have a friend who gears rear ends for race cars that owes money (good to have), did me a favor and replaced it.