Vibration Under Acceleration....Any ideas?

[LETHAL2SS]

Bought brand new DR's couple weeks ago, took it to the track launched it decently hard, wheel hopped a few times, now I have catastrophic Vibration at about 30-45 mph under acceleration only, when I coast the car the vibration stops, and when driving around under 30 MPH it doesn't vibrate, I was told by a shop (Without seeing the car themselves) that I most likely only broke something in the axles themselves. I went and bought some used axles this last weekend and plan on installing them this weekend, I'm not good at diagnosing things, so I'm hoping its not a DS issue, anyone have any insight into these things? basically just hoping I'm not wasting my time by putting these axles in...

[Driveshaftshop]

I would take a look at the Drive Shat bolts, they are known to come loose and bend

[Merc]

The DS is the weakess link and if you launched hard on DR's I'd be looking at the 12 bolts that holds the DS together.

[LETHAL2SS]

Originally Posted by Driveshaftshop

I would take a look at the Drive Shat bolts, they are known to come loose and bend

Well I took the car to a LS performance shop down the road from my place and I was told that it sounds like the posi track went out, seems like it may be pretty common in a M6 car on drag radials, kind of wish it would've been the axles first though.

the shop told me that it could be because the owner before me had put in diff fluid without friction modifier, he recommended changing it with correct fluid and driving it for a week and seeing if it fixes itself, its a pretty violent vibration i cant imagine that just fluid will fix this issue but i trust these guys. hoping for a good outcome

[Skoonie]

After I put DR's on mine I got on it leaving the tire shop and immediately spit out a drive line bolt. Replaced bolts with some stronger ones and was able to beat on it for a good 2 weeks before I killed the driveshaft center support bearing, replaced the bearing and it lasted another 2 weeks, wasted another support bearing, bought a used low mileage shaft that looked great and tore the support bearing last week. My DSS 1 piece shows up on Tuesday. Even if your shaft seems OK now, start putting money aside for a new shaft.

[Merc]

Originally Posted by Skoonie

After I put DR's on mine I got on it leaving the tire shop and immediately spit out a drive line bolt. Replaced bolts with some stronger ones and was able to beat on it for a good 2 weeks before I killed the driveshaft center support bearing, replaced the bearing and it lasted another 2 weeks, wasted another support bearing, bought a used low mileage shaft that looked great and tore the support bearing last week. My DSS 1 piece shows up on Tuesday. Even if your shaft seems OK now, start putting money aside for a new shaft.

Yep and the M6 is the hardest on the shaft compared to the A6.

[TRC-SS]

Hey lethal....sorry to bring up old post..but what was the outcome here?

thanks