7.3 IDI with E4OD 4x4 - Loud Hum / vibration ~62mph and up

[WareWolf]

Hey folks,

I'm trying to narrow down what is causing a hum / vibration when the vehicle reaches and exceeds around 62mph. From the driver seat, the vibration is minimal, but from passengers in the vehicle I have consensus it's all coming from the front passenger side and is like a massager.

The "experience" goes away immediately if I let off the accelerator. It's also not tied to RPM as I can't reproduce it going slower and pushing the RPM's really high.

Is this a u-joint?

Previous owner said the "front drive shaft u-joints" were on his list to do, but he had already done the front wheel bearings, seals, spindle bearings, breaks, rotors, calipers.

If it's reasonable that it's the front u-joint. Anyone want to spit ball what a shop might charge to do that job? Trying to decide if it's cheap enough to squeak in before the holiday so I can actually keep up on the highway hah.

Thanks

[WareWolf]

Some more notes... The previous owner also mentioned getting the tires balanced to try and stop it, and with that failing, thought the driveshaft might need rebalanced.

[WareWolf]

OK, so I've had the truck in the shop since after the new year and this is what I know so far...

The noise / vibration issue around 60mph that we as a community believed to be the passenger side hub lockout has been replaced (as has the drivers, since they are sold in pairs) and that issue is resolved.

There is another noise / vibration coming from the rear of the truck when you get into the mid-60s which I didn't know about because I always backed off from the first issue. The shop claimed it was the driveshaft, so they pulled it off and took it to a specialist company that did some magic and handed it back. Now they are saying some of the issue is resolved, but they noticed when installing it that the yoke / splines are not correct and that's causing slippage / power loss and likely the root of the drive shaft issues. I believe that from Ford, this would have been a 29-spline unit, but apparently, they are seeing 31? At this point, they aren't sure what is going on, and suspect that maybe the rear end isn't from Ford. Apparently, they can't identify it and are considering just putting the truck back together and making it my problem??? I have no idea, but I did some digging and found that Yukon sells Ford yokes with 31 splines for this year / setup. I passed that information over to the shop and I guess will see where that goes. They are closed on weekends, so I'll try to follow up next week.