onlyjuancannoli
08-01-2020, 08:14 AM
So I did an O2X conversion on my B6 so my driveline is essentially a B7 now. Trying to narrow down my driveline vibration, hoping some of you can assist with this.
I'm running 8E0 407 271/272 AH axles in front, an Automatic B7 driveshaft (rebuild with an 034 carrier bearing), GVE O2X from a 135k car and the stock rear diff from my 5spd which is the same as the 6spd diff in all the B7 A4's and ever since I started driving the car after the swap its had a strange inconsistent vibration that I can't seem to locate.
For starters, I swapped out the axles. A set of junkyard axles fixed a lot of the initial issues, and only a very mild fine vibration was left. To best explain this, imagine you have a phone on a dock, you'll see the screen image vibrate and you'll only feel the vibration in the steering wheel, door handle, and seat cushion but its extremely mind. Non car people passengers I ask if they feel that say no. Last night I swapped in a set of Duralast axles just to rule out the junkyard used ones and it is still there. Now the strange thing about this is it will come and go. I can jump on the highway and it will be fine and as smooth as a cloud, then it'll appear, then it might go away. It's not RPM, load, speed, or lateral force dependent. If I clutch in or put the car in neutral it is still there. After some initial searching I started seeing people mentions of possible worn transmission front diff bearings causing play in the axle cups. FWIW my front and rear axle flanges all have 'some' play, but they're bearings so I am to assume that without and kind of oil pressure on them they will always have play similar to the journal bearing in our turbo. There isn't really any humming or out of the ordinary noise, so I'm really at a loss. The vibration feels like its under my seating area, but I touch the floor and I feel nothing. I started thinking maybe its something to do with the transmission mount or the crossmember bolted to the car under some kind of stress, but wouldn't that go away if I put it into neutral, or would it still be there because the driveshaft is spinning whenever the car is moving? Any help is appreciated, Thanks guys!
I'm running 8E0 407 271/272 AH axles in front, an Automatic B7 driveshaft (rebuild with an 034 carrier bearing), GVE O2X from a 135k car and the stock rear diff from my 5spd which is the same as the 6spd diff in all the B7 A4's and ever since I started driving the car after the swap its had a strange inconsistent vibration that I can't seem to locate.
For starters, I swapped out the axles. A set of junkyard axles fixed a lot of the initial issues, and only a very mild fine vibration was left. To best explain this, imagine you have a phone on a dock, you'll see the screen image vibrate and you'll only feel the vibration in the steering wheel, door handle, and seat cushion but its extremely mind. Non car people passengers I ask if they feel that say no. Last night I swapped in a set of Duralast axles just to rule out the junkyard used ones and it is still there. Now the strange thing about this is it will come and go. I can jump on the highway and it will be fine and as smooth as a cloud, then it'll appear, then it might go away. It's not RPM, load, speed, or lateral force dependent. If I clutch in or put the car in neutral it is still there. After some initial searching I started seeing people mentions of possible worn transmission front diff bearings causing play in the axle cups. FWIW my front and rear axle flanges all have 'some' play, but they're bearings so I am to assume that without and kind of oil pressure on them they will always have play similar to the journal bearing in our turbo. There isn't really any humming or out of the ordinary noise, so I'm really at a loss. The vibration feels like its under my seating area, but I touch the floor and I feel nothing. I started thinking maybe its something to do with the transmission mount or the crossmember bolted to the car under some kind of stress, but wouldn't that go away if I put it into neutral, or would it still be there because the driveshaft is spinning whenever the car is moving? Any help is appreciated, Thanks guys!