Constant Hum 2000 Xp A4WD

[Duksta]

I have a 2000 XLT XP A4WD. I have a constant hum coming from what seems to be the front end. I have got under it to see if I can find any slack. All I can seem to find is a slight play in the front drive shaft where it connect to the transfer case. I can slightly wiggle what seems to be the shaft comming out of transfer case. Is this the norm or do I need to start looking for a new transfer case. I have the 104 fuse pulled because when it is in I have a shudder when I accellerate... Any tips or info would be wonderful. Looking for a starting point to investigate...

 

[jacks3am]

check your cv boots, mine are shot and they hum and make a binding noise when crawling around.

 

[Thermo]

Duksta, what I want you to try is drive down the road at high way speeds and do a controlled fast speed lane change or find a corner that you can take up near highway speed (a semi sharp corner in a highway is good enough). What I want you to do is to be able to turn both left and right as the humming is occurring. If you notice that the humming goes away when you turn one way, but remains when you turn the other, the direction that you turn to make the noise go away is the side with a bad hub. Replace the hub. I bet your noise goes away.

 

[jacks3am]

Thermo is right it could easily be the hubs, but I would suggest finding some local twisties, the freeway turns are just not agressive enough!!!!! if it goes away when you turn, then comes back, hubs.

 

[Thermo]

Normally, the easy way to check to see if it is the CV joints is to back up. If the noise changes, then it is the CV joints (goes from a hum to a click). If it remains a hum, then odds are it is a hub assembly.

 

[Duksta]

Ok. I did as you sugested and I do not here any change in the hum. I did raise the truck and was able to detect top ball joint on control arms have play in them on both sides. I am ordering new hubs and control arms to replace them. Will let you know what I find.

As far as the wiggle im getting from the transfer case and the shudder im getting under acceleration when in A4WD. Any Advice there....