05 expedition intermittent hum/grind from drivers front wheel, creaking when turning at low speeds and some fluid on front diff

[StealthExpedition]

I recently picked up an 05 expedition eddie bauer package 4x4 and its got about 158k miles. It runs strong but when started on a cold morning has been making a weird low hum that feels/sounds like a slight metal on metal rub coming from the drivers front wheel. I think it might be a slight loss of vacuum on the 4x4 system that could be causing it to try and engage mildly while going. It seems like after the first 500yards you drive the truck and make a few turns (which the suspension has a few loud creaks and groans) the grinding/humming stops and it just has the suspension creaking. I looked under there today and it looks like theres just a half drop of some fluid on the front differential? I checked all fluids top side and they are good. What do I need to check on to get the creaking, grinding, and leaking to stop? Also if there are any lube points or good general knowledge for a new 05 expedition owner I’m happy to learn.

 

[StealthExpedition]

 

[StealthExpedition]

Sorry for the rookie extra posts (max photo limit 5). Also wanted to add this is in 2WD when the grind/rub happens

 

[Hamfisted]

My guess would be the hub lock actuator on that hub is starting to fail ( vacuum leak...) and letting the hub partially engage. Not enough to "lock" the hub, but enough to get the chatter of partial engagement. If the actuators haven't been replaced before, it's just an age thing. The internal diaphragm cracks and just allows a vacuum leak. Vacuum is needed to keep the hub disengaged during 2WD operation. The creaks and groans are probably the front lower ball joints. If they're original, at that age and mileage, have an alignment shop evaluate it to give you a better idea.

2005 Expedition Front Hub Actuators at Rock Auto










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[whtbronco]

It could be the 4wd hub or the wheel bearing hub making the grinding noise. If it's the 4wd hub it could be be the vacuum hoses, the vacuum solenoid or the vacuum operated integrated wheel ends(IWE), aka 4wd hub, making the grinding. Have you jacked it up and tried to turn the tire to see if you can identify it? The hub is engaged without vacuum and engaged with vacuum. If there's a leak in the vacuum system it can partially engage the IWE. You could also try selecting A4WD which will leave the IWE's engaged and if the grinding noise goes away it's very likely to be the IWE, solenoid or vacuum hose leak.

The creaking is suspension and likely a ball joint, could be a steering outer tie rod end too. If you can grease the ball joints and outer tie rods it may subside. If you do one at a time and take short drive you can isolate the fault.

The leak I would look at the front differential cover and a common leak is the pinion seal. Could be coming from the engine oil pan too or other engine oil seals. A few drops of oil leaking from the engine would be impossible to notice on the dipstick. Oil leaks can blow oil all around so getting under there with a bright light may be required. Cleaning everything up is hugely helpful too in finding the source of a leak. Keeping things clean helps with finding future leaks and makes working on everything easier. it doesn't really look terribly dirty though.

 

[StealthExpedition]

Thanks for the advice everyone. Im going to investigate the vac line and see if that resolves it. Makes sense a 20+ year old vac line might get worn or dry rotted somewhere and thats letting it try and partially engage. Going to jack it up and investigate. I will also get under there better to see where it looks like the fluid is coming from. The old creaks and groans arent too bad but would be nice to get smoothed out while im down there working on it too. I will report back when I have updates.