AWD Noise in front drive train

[garyt]

Just got back from a Thanksgiving roadtrip and noticed the front drive (AWD) was making more noise than usual. Not sure if it's coming from one of the wheels or the differential. Checked the fluid level in the front diff and it was fine. I would normally go to making sure the wheel bearings are greased, but have seen threads that say that the AWD doesn't have servicable front wheel bearings. Don't really know where to go next in diagnosing it. Any ideas or similar problems?

By the way, with the Apten chip and fresh plugs, I averaged a little over 20 mpg when going between 70-75 mph for the 300 mile trip out. On the way back, at 85 mph, the fuel mileage took a nosedive back to 15 .mpg

 

[section525]

What kind of noise?

 

[plrs x45]

If the noise is like a whine (especially when turning) then it may be the hubs. I had that problem and just changed mine and no more noise. They are not cheap though, the hubs set me back 140$ each.

Good luck

 

[SWLathrop]

Are all 4 tires identical? Just something to check because we had a 99 Mounty in for front end noise. Problem was the customer had 2 Wrangler RT/S on the rear and 2 Wrangler GS-A on the front. Even though they were the same size (P235/75/15) they were physically different sizes. This was causing driveline binding. Problem solved by replacing the other RT/S's with GS-A's. The customer got cheap and had only replaced the 2 worse RT/S's. The other 2 were almost worn out also. So instead of paying for just 4 new tires, it cost them 4 new tires and diagnostic time.

 

[garyt]

Clarification

The noise is like a whirring noise rather than a whine. It is most noticeable on deceleration when slowing down and isn't any louder or softer when turning.

All 4 wheels and tires are the same.

 

[SRS]

Internal T/C noise

My '98 AWD recently started making a noise within the transfer case. It can be heard at low speeds, under 15 mph, as a whiring noise best described as a chain and sprocket trying to mesh. Investingation with it running in gear while on jack stands indicates it's within the 4404 T/Case. The front output flange seems to have about .100" in-out endplay, which indicates that the thrust control surface (bearing/washer) is worn. Perhaps that's causing a misalignment with the chain and sprocket.

I plan on pulling it soon and doing a bearing/seal/gasket/chain rebuild. The truck just passed 100K with no other mechanical problems up to this point.

Steve.

 

[macoffma]

I've had the same problem--it started about 1.5 months ago in my '99 mountaineer w/ awd. Now I am noticing a grind on initial acceleration, especially when turning from a standing start. My first thought was hubs but a dealer inspected and said no issue. The brakes are low but still have 4-5mm of pad left. I can feel a definite vibration from the floorboards and the problem is getting worse not better.

Is there anyway I can test the hubs before buying the replacements, especially since they are sealed assemblies?