I think I've found the front end clunking when 4x4 engaged....?

Discussion in 'Transmission & Drive train' started by Wal92tt, Oct 3, 2018.

  1. Wal92tt

    Wal92tt Well-Known Member

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    Sep 8, 2018
    Riverview, Fl
    1999 Expedition EB 4x4 229,8xxmiles
    The front end started clunking very loudly last week. It sounds like a loud metal on metal banging/clunking which gets louder with speed. It obviously was related to the rotation with the front end. I tried shifting in forward and reverse a few times and it went away. Well while tinkering underneath with the transmission shift sensor, I took a look at the front differential. Well the drivers axle was pulled out of the differential a few inches. I was able to pull it out and back in with about 4" of play. Later I drove out of the driveway and the clunking was back. I pulled over, went underneath and pulled the axle back out and drove around the block. The clunking was back. So now I know the source of the noise!

    Now I need to figure out what exactly happened/caused this. Has something holding the axle shaft in place come loose or fallen apart? The axle shaft, (not sure if that's what it's called?), looks to be about 13-14" long in pictures online, but on the truck it looks like it's maybe 6-8"? Maybe it actually is 14" but snapped? If so, is this an easy fix for me to tackle? I'm very mechanically inclined and do most of our vehicle work myself? It looks like it will involve removing and taking apart the differential?

    In the diagram, the part in question is #1, which bolts to the cv half shaft.

    By the way, I wish there was a way to filter searches based on generation/year of vehicle on here.

    My truck:




  2. Gary Waugh

    Gary Waugh Full Access Members

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    Jun 27, 2017
    Princeton, TX
    I could be wrong, but there are usually snap rings on the end of the inner shaft that slide into the differential gear and lock the shaft in. I would suspect yours have come out or broken, you usually need to remove the drive shaft completely from the differential housing and you will normally see a machined groove in the end of the drive shaft where the ring sits. None of this is shown in your microfiche diagram and I don't know if this is how ford has done it on the expedition, but that is the common way that those shafts are located on most vehicles. If the clip has broken and come of, you really need to open the diff and find the old clip, the parts are very cheap, but the ring will damage the differential if left inside!! If you are lucky the spring has just compressed and you can take it off, put a new ring on (a few bucks) and put the drive shaft back in and push it home, the ring should then lock the shaft in place and you are good to go.

    justKen likes this.
  3. justKen

    justKen Active Member

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    Aug 7, 2018
    Colorado Springs, Colorado
    ^^^^^^^^^^ THIS - get that diff cover off and clean it out. You'll likely need to replace the seal on that side as well. It is **possible** you can walk away from this relatively unscathed other than some funky 90wt. and a couple hours of work, but every turn this axle/ diff makes is like spinning the cylinder in a game of Russian roulette.

    With the truck supported, diff drained and the cover off, inspect EVERYTHING closely - R&P/ carrier/ spiders/ bearings/ etc. There should be enough gear oil retained in the bearings that will allow you a good feel of how smoothly things are mating (or not) by turning the drive shaft by hand. Be sure to clean the diff housing completely to ensure there are no metal shavings or chunks hiding in the murky oil.

    Edit to add -

    I would also replace the bearing for that side of the axle housing while at it. Pay very close attention to the bearing seat to see that it's not beaten distorted already, as well as the machined surface of the axle shaft.

    Last edited: Oct 6, 2018

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