CV Axle Bounce - Shops Can’t Diagnose

Hi all, been lurking since I bought my Passat last August but this is my first post. Unfortunately, TDI ownership has not been kind to me and my car has spent quite a bit of time in the shop. I have a vibration no one in my area can figure out.

I have had 3 alignments done, 3 wheel and tire balances, 1 road force balance, 2 new tires, a new CV axle and a new piece the CV axle bolts onto (transmission? Not familiar with the engineering of these European cars yet). 4 shops have confirmed the wheels are not bent and tires are not out of round.

This has not fixed my issue. The vibration can be felt almost constantly, and is particularly more noticeable on fresh paved, flat roads and interstates. The steering wheel does not shake, but everyone who rides in my car for any extended amount of time can notice the slight vibration and you physically see legs shaking and sun visors and seats vibrating. It’s not engine vibration because it doesn’t shake when sitting still.

In have videos, but can’t figure out how to attach them from mobile. On the drivers side CV axle, you can see how the inside portion of the CV axle bounces while in drive with front end on jack stands and wheels off. Any ideas what this is?

I like my car but I’m about to give up and sell it if I can’t figure this out soon.

Where abouts in Indiana are you?
Where did you get the car? Buyback fixed car from dealer? How many miles? It almost sounds like its a frame issue... never been in a collision?

In oddities in the alignment? I might have pulled a dukes of hazzard in a ford explorer way back when enough to bend the axles to where i had a similar problem. You couldnt re align it enough to get it back into spec.

This really shouldn't be a difficult thing to pin down. I can think of a dozen or so things but a couple of them will be more obvious than others such as tires. A simple thing you can do is having someone drive your car at low speeds while you follow and observe both outside of tires and inside as well. I would suggest going to a shop that deals with fussy owners, Porsche or Audi, race car builder, or similar. If you replaced 2 tires, I'll assume fronts, rear tires, particularly if something crap' may have lump or sidewall problem which might explain no feedback through steering wheel. you haven't told us what brand tires you put on.

Lex Tdi said:

Where abouts in Indiana are you?
Where did you get the car? Buyback fixed car from dealer? How many miles? It almost sounds like its a frame issue... never been in a collision?

In oddities in the alignment? I might have pulled a dukes of hazzard in a ford explorer way back when enough to bend the axles to where i had a similar problem. You couldnt re align it enough to get it back into spec.

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I’m in the southern Indiana region, about an hour from Louisville. I bought the car in Greenwood as a certified pre-owner car. It was buy-back fixed by the dealer and sat somewhere for a year and a half between buy-back and auction. It had 34k at the time and 45k now. According to car fax it has never been in a collision and had all work done at original VW dealership including wash and detail.

The 3 shops that have done an alignment say its good-to-go. The last time I asked for a copy of the alignment I was told the machine’s printer was broken. But they also managed to strip the rear bearing pulling the lug bolt out and then threw away the lug bolt and cap. That’s one shop I’ll never be back to lol

thundershorts said:

This really shouldn't be a difficult thing to pin down. I can think of a dozen or so things but a couple of them will be more obvious than others such as tires. A simple thing you can do is having someone drive your car at low speeds while you follow and observe both outside of tires and inside as well. I would suggest going to a shop that deals with fussy owners, Porsche or Audi, race car builder, or similar. If you replaced 2 tires, I'll assume fronts, rear tires, particularly if something crap' may have lump or sidewall problem which might explain no feedback through steering wheel. you haven't told us what brand tires you put on.

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I agree, I would have thought a reputable shop would be able to identify and fix this without issue. I can have my wife hop in the car and I’ll follow behind her. I have stood on the road and had her drive toward and away from me without noticing anything, but maybe with a little more speed I’ll see something.

Unfortunately, the nearest European car shop to my house is about an hour away, but that may be what I need to do. The tires I put on match what came on the car when I bought it, Continental Conti-pro contact? Or something along those lines.

If the car sat for a year and half, the tires are no good. We are seeing this with pretty much every buyback car that comes in here. The tires are old, flat spotted, and no good OR, they slap some no-name Chinapop garbage on there. Either of these will result in less than perfect road manners.

If there is a direct relationship to road speed, and no change in intensity if under acceleration, then it is something in the rotating assembly balance. Since I very much doubt your transmission's differential carrier somehow got out of balance on its own since it left the factory, that leaves the axles, rotors, hubs, wheels, and tires. Tires being the most likely culprit. An axle issue would generally manifest itself as a change in intensity (worsening) while under acceleration, ESPECIALLY with the torque heavy TDI.

oilhammer said:

If the car sat for a year and half, the tires are no good. We are seeing this with pretty much every buyback car that comes in here. The tires are old, flat spotted, and no good OR, they slap some no-name Chinapop garbage on there. Either of these will result in less than perfect road manners.
If there is a direct relationship to road speed, and no change in intensity if under acceleration, then it is something in the rotating assembly balance. Since I very much doubt your transmission's differential carrier somehow got out of balance on its own since it left the factory, that leaves the axles, rotors, hubs, wheels, and tires. Tires being the most likely culprit. An axle issue would generally manifest itself as a change in intensity (worsening) while under acceleration, ESPECIALLY with the torque heavy TDI.

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I have a buddy who has a TDI Jetta, I’ll see if he will let me swap wheels and tires for a little test drive. Then I’ll be able to narrow it down, wheels and tires or axles/rotors/hubs

An out of round tire may balance but still give the symptoms you have. Definitely tires as a first try!

seat, and other interior seat etc vibrate/nothing in steering wheel shakes it points to rear wheels.

boomer1 said:

An out of round tire may balance but still give the symptoms you have. Definitely tires as a first try!

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I agree with the suggestion that tires are the next thing to swap. Better yet, could you find a set of good wheels and tires to try on it? If your dealer has gone through everything else then maybe they'd be willing to swap a wheel and tire set off of another car to take it for a drive.

This thread has been helpful for me as well. I have a really annoying vibration in my JSW that was not noticeable when I bought it CPO about a year ago. But since last fall its had a vibration that I couldn't figure out and it pulls lightly to the right. My car had brand new tires on it when I bought it so they shouldn't be the issue unless one is bad. I took it to a shop for an alignment and wheel balance but they said both were fine. However, my other symptom is that my car pulls much harder to the right under acceleration than when coasting.

So based on what Oilhammer posted above it sounds like my issue could be a bad axle. It looks like I need to schedule its first trip to the dealer under my ownership to see if they can diagnose and fix it under the CPO warranty.

A vibration under acceleration points to an issue with a drive axle. A pull does not. A pull would point to a change in the steering/suspension angles, something like a control arm bushing, loose subframe, loose steering gear, or upper strut mount bushing.

My car was pulling also. Usually to the right, but other times left. I was mindful of road crown. LF upper strut mount was also making a noise when going over bumps and turning. Dealer replaced that strut and mounts, and no more pull nor noise.

I also notice some vibration, but chalked it up to irregularities in the roads I drive on. Looking deeper, I might have a mild case of the DTs too. Staying tuned to this thread...

Adding to what oilhammer said: a subframe misalignment will cause a pull. Alignment readings will rule that in or out. misaligned subframes are more common on passats than on golfs.