Motor mount/cv question

**LowA4** · 11-17-2008 08:30 PM

I made a 200 mile drive today and everthing was going fine. On the way home, I passed somebody in the passing lane and slowed back down. When I accelerated again, I got a bad low frequency vibe coming from the front, felt like it was more on the driverside, like my wheel was going to fall off. It only does it on harder acceleration. I know that the motor mount on that side has leaked all of the fluid out and new 034 mounts and snub are going in. I thought that the mount may have actually broke off around the top like my A4 did. I decided when I got home to get under it and look at the cv/steering components. I noticed that the driverside cv moves in and out about 1/4", maybe a tad more. It doesn't move at all when I grab it and push and pull, just in and out (trans-wheel) The passenger side doesn't and I checked my A4 and they are solid. The boots are in great shape with a little grease oozing out under the boot at the inner clamp, but it's not ripped. Is this cv shot or would it be the motor mounts causing the vibe? It makes no noise what so ever, just started vibing.

**S4 in_lowplaces** · 11-17-2008 08:41 PM

Well the axle is supposed to move in and out because of the joint inside. Pic for reference

Or do you mean the the actual flange that bolts up to the tranny is moving in and out? Vibing your getting is most likey the mount.

**LowA4** · 11-17-2008 08:47 PM

Not the flange, just the shaft itself within the joints. Maybe I should repack it though.

I just thought it was wierd since it is just that side, and on my A4 they're solid. I'm leaning more towrds the mount also but want to check. I guess if it still does it when I replace them then it's the cv.

**LowA4** · 12-08-2008 05:29 PM

Well, I installed the PITA motor mounts and trans mounts and it still has the vibe on acceleration. It isn't nearly as bad now and only does it at speed so I'm thinking the driverside cv shaft. It was doing it from a stop. I just don't think the shaft is supposed to move in and out that much. It moves an inch or more. I can now hear what sounds like the shaft moving in and out with light pressure on the gas. When I move it by hand, it makes a popping sound and it's the same one I'm now hearing inside the car. I'm ordering a new cv and I'm getting the rear diff bushings too.