2002 Mountaineer Differential/?????? - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars

kylec2003 · 02-18-2010, 14:13

So I have an AWD/4.6L with 115k, around 100kish it started to have a hum that sounded like it was coming from the front and the only thing that made the noise quit was turning left. Going straight or turning right the noise was the same, so I replaced both front wheel bearing. Although both bearings were bad this did not fix the issue of the noise. So yesterday I get the fluid in the front and rear diff and the transfer case changed. About a mile from the shop I hear a off an on noise of like rotating metal on metal from the rear. I go back to the place and asked them to make sure that they used the friction modifier and they showed me the empty bottle and then added a bit more thinking maybe that would help. Well needless to say it did't. On the way home I notice the noise is way worse at low speeds and turning right, but the weird thing is as soon as I turn left the noise goes away again. Is it the clutches or the gears????? Also I live in WA state and I am traveling home to AR. Will it make it there where I can change it out in my parents shop?? Thanks

**360ci** · 02-18-2010, 17:27

I can't say if you'll make it anywhere. However, I'd check that you're not driving with the axles locked (4HI engaged) and that it's in fact AWD or 4 Full Time mode. I would assume that you have a bad axle. If gears are properly maintained they'll last forever (for the most part).

If it's a chattering sound (like you had mentioned; metal on metal) that increases with speed, then you more than likely have a problem with at least one axle. Be sure to phone the shop, ask to talk to the guy who did the work and see if they found any metal pieces in the rear axle when the fluid was changed. This is assuming that he removed the cover, instead of sucking out what fluid he could get out and charging you full price for a half-as$ed job. If he did find metal, other than fine metal dust on the magnet then the clutch packs can become loose in the pumpkin and grind together depending on wheel rotation.

If your parents have a shop with a vehicle lift, put the vehicle on the lift, and put the transmission in to park and make sure it's a frame lift, and that the wheels are off the ground. Now, turn the wheels. The wheels will all turn in different directions, so don't be concerned with this as it's normal for AWD vehicles. Try turning each wheel at a good pace, and see if you hear any noise. If you do, then you can narrow it down by getting a relative or friend to turn the wheel while you pinpoint the source of the noise.

kylec2003 · 02-18-2010, 18:28

The mountaineer doesn't have any selection for 2x4 or 4 hi/lo its just all time AWD. I like your idea about using the lift which is a frame lift, but it is 2000 miles into my road trip till I make it to there place. The place that did it just pulled the drain plug and didn't actually pull the casing apart. They said they didn't notice anything abnormal. I just find it odd that changing the fluid made such a drastic difference in the type and loudness of the noise.

**360ci** · 02-18-2010, 18:32

The only way to know for sure is to pull the cover off and check the magnet. If your differential has "C" clips on it, they can fail, or break into several pieces which allow free movement of the clutch packs - not good = generally means a rebuild.

I find it strange that he can just siphon out the old fluid and say that it's OK! I don't buy it.

kylec2003 · 02-18-2010, 20:25

Is the clutch pack in behind the ring and pinion??

**360ci** · 02-19-2010, 12:51

If your ring gear is on the left, then inside, where the axles would come together is where the clutch packs are located, and that's where the 'C' clip is located, holding them on. The pinion is at the front of the housing, as the driveshaft connects to that in order to turn the ring gear.