When I switch to AWD everything works fine for a few minutes, then I can start to feel a rumble getting gradually worse until I have to switch back to 2 WD after 5 min. I figure it's probably in need of a tranny fluid change but just want to make sure.

Suggestions? Anyone else had this??

Thanks

 

If you can switch to 2wd drive than it must be A4wd not AWD but similar. It may be that there is an issue in the A4wd system that is partly engaging the front axle. If it goes away when you switch drive modes it wouldnt be affected by the transmission.

 

I was meaning A4wd, didn't realize it was called that. So, any ideas on what it could be in the front axel that would cause it tostart rumbling after 5 min. of straight driving?? Anyone??

Thanks,

 

I dont think it is the front axle it is most likely the transfer case partly engaging. Does the light on the controls blink when in A4wd or anything that it doesnt do it 2wd. Someone with more expirence with the issues with the controls of the switchable transfercase should be able to walk you through diagnostic steps. My AWD system doesnt have the ability to go into 2wd mode so I dont have all the vacum controls.

 

Thanks for the post. The light for A4wd comes on properly and I am sure that the transfer case is engaged properly. I've tested it a few times with the recent snow we've had. Big difference in traction from a stop.

That's the thing that concerns me, if it works fine for a few minutes at highway speed, then starts to rumble, then stops immediately when you switch back to 2WD, just wonder how/why. I often will switch to AWD on the highway when it's snow covered and slippery, the switch it off when you get to a clear area. I've always found it switches very smoothly.

 

Have you checked the diff fluid?