Howling Yukon 2004...Help!

[black79ta]

Hi Guys, I have a 2004 Yukon AWD 5.3 140k miles I have a howl in the front end. what I have done, changed the fluid in both diffs and the transfer case. the rear diff and the tcase fluid looked pretty good also. the front fluid was a little low and there was some metal paste on the plug but not an large amount. I also replaced both unit hubs with timken's. that helped but the howl is pretty loud still. I am looking into getting a wireless microphone set up that I can place mic's on the bearing housing and try to isolate the noise. It is at all speeds but is worse when decelerating from 30-40mph. couple of vids while driving

http://www.youtube.com/watch?v=_1Kn0jvNsxM

http://www.youtube.com/watch?v=MLUX98s4WMI

If I determine it is the front diff I am going to give a shot at rebuilding it myself.

 

[Sasquatch]

I don`t have AWD but from reading many threads about it here it`s well known that AWD eats up front differentials at about how many miles you have.

Since you`ve replaced all the other parts it looks like it is the diff but hopefully someone else that has had the same problem sees this and confirms it for you.

 

[black79ta]

well I bought Steelman's ChassisEar...wireless mic system. will hook it up this weekend to figure out the problem. also I sill check the rear diff. Pumped!

 

[B0$$MAN]

I have a humming sound too. It happens between 35-60mph when on the throttle. When I get off the throttle or decelerate it goes away. From the research I've done, some forum members have come to the conclusion that it's the ring and pinion either in the front diff or rear diff; your mic test will confirm which one it is.

Interested in hearing your findings with the mic.

 

[black79ta]

thanks for the comments. My howl is all the time with it worse when decelerating. I think it is from the front but will find out for sure.

 

[coolchuck]

Keep us posted.

 

[Time2Kill]

If the howling gets worse when decelerating, its likely a bearing in one of the diffs/axles.