Vibration Under Load
 

I have run into a somewhat peculiar condition with my 2001 Allroad and thought I'd see if anyone else had some related experience. This summer my car has developed a subtle but quite noticeable vibration that seems to be engine RPM dependent and becomes most evident above 3000 RPM when under load (accelerating or climbing steadily up a steep grade). The vibration is seems to be coming from the front and is perceptible through the feet (pedals/floor boards) and hands (steering wheel). I'm suspecting that it may have something to do with either the engine mounts or possibly a bad front axle. The car has ~130k on it.

It is definitely not tire balance or alignment related.

Any ideas?

Thanks,
Don

On my 6mt allroad, that vibration got more and more pronounced. It went away with replacement front axles from Raxles. The old axles produced no clicking sounds typical of bad joints and showed no torn boots or other indications of failure.

Vibration while accelerating is a common symptom of a cv joint failing. Check the boots for anything obvious, but they can fail without visible wear, as Kneale notes. Another vote for Raxles.

Thanks much for the feedback! I kinda figured that the axles were the most likely cause. Is there convenient way to inspect the CV joints prior to ordering replacements to confirm the condition?

Don

Not that I know of. If the boots are torn and you have the characteristic grease spray then you can be assured the CV joint is done. With everything else, it is often just a vibration, clunking, and feeling. That isn't to say it is the only possibility, but motor/transmission mounts don't tend to be RPM or load dependent (worn mounts often vibrate with no/little load in my experience). There are other drive line joints/bushings it could be but axles are more common. If you've check the tires/wheels and done the usual front-end checks, then it is probably one of the CV joints. If there is a reputable indy shop in your area, you could bring them some coffee and ask if they would mind taking it out for a spin and offering their opinion.

I concur on the CV axle diagnosis. Mine did the same thing.

On my 2002 TIP, I could grab the CV and if I really jerked on it you could feel some up/down movement in the joint. That was enough to cause the wheel to vibrate and shudder under moderate load. In my case, hard acceleration masked the problem.

Could be the driveshaft support

As a follow-up to this thread I did replace both front drive shafts with units from Raxles and the problem was resolved. The front left inner CV joint was in the worst shape, once off of the car it would simply rattle as you moved the CV joint around by hand. We have driven the car a couple of thousand miles and no vibration.

So on to the next problem.... :-)

Don

Thanks for updating, Don.

As mentioned I replaced mine, but only the LF and it was also the inner that was shot. Now it seems I should have just replaced both since I'll be taking it for another wheel alignment because the RF is now acting up.

i to am getting this from my audi A4 it only happens when at arount 2500 rpm and comes up from the stick the car is 2002 with 139k miles on it