Well, I thought I would do the cheap insurance thing and change all my fluids, even though they are "lifetime fill". So, I did the tranny, (02 tip) the center diff, and the rear diff. It drove fine for a while and now I have a strange rumble when I take off from a stop a turn at the same time. It is like a differential is lockinh and unlocking, or sticking, if that is possible. I think I went wrong on the rear, I used gl-5 mobil 1 synthetic 75w-90. I did some research and read that that stuff was ok in the rear. I have since taken it out and put in the audi 75w-90 fluid, but the noise is sitll there. I re-checked the levels in both differentials, and am in the process of checking tranny level now. I listend outside the car while a friend drove it in circles and you can't hear anything, just in the car. It is an '02 A4 Avant, 3.0 tip. Any thoughts? Did I smoke one of my differentials?

 

I have a B5 and mine does the same thing, it's like a vibration/rumble when turning at take off. i would be very interested in what that could be also. Good Post!

 

Has your always done it? I am planning a long drive this weekend (well, in about 20 minutes actually) and am wondering if I should take the audi or not......Mine just started doing this after the oil changes.....

 

did u monitor the level at the correct temp? a vagcom is needed to monitor the temp while u fill it. do u also feel a vibration too?

 

Mine has done it since i bought the car about 2000 miles ago, and before and after i had all of the fluids done including the transmission. and replaced all four axles and one front and one rear wheel bearing, also had the center diff rebuilt!

 

I didn't use the vag com but I used an ir thermometer on the pan, after it had heated and cooled a little to kind of catch up to the oil temp. I also put in about the same amount of fluid as came out of the trans. I do feel a vibration, but it only does the noise/rumble when I am turning, take offs in a straight line are smooth, as is the shifting, that's what makes me think it is a differential.....

 

Not sure I want to take a chance...we will take the wifes car. Thanks for the input so far guys, I will be back on here on Monday.....

 

well alot of the time our audis come with overfilled trany fluid. i've seen many post where people drained and only filled bout 1 quart less. u kno the wheel bearings are a thought. wut ur describing is pretty weird. pm auditech79 or techbod. they should be able to give better help

 

Re- checked my fluids all around, everything was fine. I could see it being the tranny because it shares with the front diff but I think I would feel that in the steering and I don't, that maks me think it is the center or rear diff. The car is clearly not happy after the fluid change. I will try to pm the techs for some help!

 

is your car an automatic or manual? Because....on the manual, the front diff and trans share the same fluid....but, in an automatic they are seperate.