UnoDosTurbosQuattro

Well, still no resolution from Audi USA, 2 dealers, or private mechanic on my 35mph-65mph wobble. (previous post is https://forums.audiworld.com/allroad/msgs/91963.phtml )

CVs, axles, suspension, geometry, wheels, tires (new), alignment all reportedly look OK. Front rotors pulsate a bit, but I don't think it has anything to do with the wobble, as it is under throttle only.

Car is out of warranty so nobody will take a shot and swap in a new TCU without charging full price (with no return possible). And no luck at salvage yards.

One new interesting observation:
Wobble is worse when the car is jerked in one direction (while under throttle). At first I thought it was when turning left (loading up right side), so I was hoping RF CV or axle was bad even though it looks OK. BUT...now I've discovered that the wobble is worse when:
(1) turning right while in suspension III or IV
(2) turning left while in I or II
Very interesting. But after sharing this clue with all involved, they're still CLUE-LESS.

Should I take a $550 "guess" on a TCU?

Will diagnostic tools report any error codes with torque converter, etc? (have no tool - yet)

Anyone have an '02 or newer AR tip, live in or near MA area, and want a case of beer to swap TCUs for 5 minutes?

Any other thoughts?

Oh great AR forums members, please speaketh.

ShowMeData

I tried to log, using VAG-COM, the torque converter lockup signal to see if that was causing my vibration. I determined that the sampling rate of my VAG-COM was not high enough to detect the frequency I was trying to find.

I think the more expensive VAG-COMs may have a higher sample rate, but I still don't know if it would be high enough.

Studly_1

Shot in the dark - check U-joints.

UnoDosTurbosQuattro

...they put in on the lift, ran the car in gear, and saw nothing out of the ordinary. Of course, there was no load.

Would love to reproduce the problem on a 4-wheel dyno (rolling road) but not sure where the nearest one is.

All Italian

OK have you tried different tires?

UnoDosTurbosQuattro

Also balanced wheels and did 4-wheel alignment (RF was out a little). No change at all.

Curious that original RR tire was bald and RF not great, though both LF and LR were fine. I attributed this to RF toe problem, and last owner was probably lazy and swapped RF to RR without fixing the alignment.

Studly_1

After re-reading your post I still suspect CV joints, or maybe Torsen diff lock

MeLoN BaLLaR

I wonder if your rims are either slightly bent, or not balance-able (explained below).

I heard of an '01 Allroad at a SoCal that had a wobble similar to what you describe. They replaced EVERYTHING. Still wobbled. Some tech suggested taking the two piece rims apart, and cleaning the space between the rims. Someone suggested he was an idiot. A month later, they did it out of desperation, and found the space packed with brake dust. They cleaned, reassembled, re-balanced the rims, and the wobble disappeared.

This whole story may be urban legend, but it is easy to check. Slap on another set of rims. Borrow some from someone, or tell the dealer to do it. See if it makes a difference.

HTH,

Studly_1

Then disconnect at high speed.

UnoDosTurbosQuattro

the wobble seems to be present at higher speeds than this. Although - I think it goes away above ~75 or 80mph.