Driveshaft squeak

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Feb 22, 2020 | 09:47 AM

oskarol

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Driveshaft squeak

My 07 expedition has a rear end squeak that I am trying to diagnose. Here is where I am at.
- squeak sounds similar to a warped rotor. Brakes are fairly new (6m) and spinning the wheels by hand doesn't reproduce the sound.
- squeak only happens when not on the throttle and is independent of braking. No sound when idle and is independent of rpm. Sounds like it is coming from the middle to rear end of the truck
- squeak is speed dependent, but I can't hear it past 40km/h. I'm guessing it is there but is getting drowned out.
- squeak only happens when it is cold and during the first 10 minutes of driving. then it is gone and won't come back until after a cold soak.
- squeak occurs with the engine off and rolling
- squeak is from the rear. I jacked the rear end up and put it in drive... squeak was there. I didn't have the guts to get under it to get a closer look and I'm diagnosing it solo. Spinning the wheels by hand, I can't reproduce it.
- I thought for sure it was the ujoints so I hit the the zirks with grease. They look okay, no play. After greasing, no change in sound at all.

Any thoughts on what it could be or what else I can try without climbing under it with it in drive?

Feb 22, 2020 | 09:55 AM

alloro

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Did you check the fluid level in the rear end?

Feb 22, 2020 | 01:27 PM

oskarol

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Checked the fluid level in the diff, gave it a little top up but it was okay. Squeak still there.
Should mention I also had previously checked the wheel bearings, they feel tight.

Feb 22, 2020 | 01:35 PM

ford390gashog

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Well the u joints don't have grease fittings stock so someone has replaced the u joints previously. Have you inspected the CV shafts?

Feb 22, 2020 | 01:42 PM

oskarol

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Quote:

Originally Posted by ford390gashog

Well the u joints don't have grease fittings stock so someone has replaced the u joints previously. Have you inspected the CV shafts?

CV boots look okay but is there a way to check them?

Driveshaft and ujoints were replaced just before I bought it, which was 2.5y ago.

I have also pushed back the rotor dust guards just in case, but dont hear anything when spinning the wheels by hand.

Feb 22, 2020 | 02:04 PM

oskarol

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The squeak really does seem like it would be a ujoint.

If I greased both ujoints and even if one was on it's way out... you would expect the sound to dissipate... wouldn't you?

Feb 22, 2020 | 04:14 PM

oskarol

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Decided to take my driveshaft out again and check the ujoints as it had been some time since I had pulled it to check them.

Front ujoint is floppy in both axis.
Not sure why I dont remember this but the rear ujoint is floppy in one direction and stiff in the other. The stiff axis will move by hand with a little force but wont fall on it's own if the shaft is horizontal, for example.

Thoughts on if the rear ujoint be my squeaky issue?

Thanks for the help.