Red97Z

iTrader: (22)

Whenever my car hits above 87MPH, the entire car, shakes and vibrates like crazy. The car can be in neutral, 5th, or 6th and it will rattle and vibrate so much that the change in my cup holder often times jumps and shakes right out of the cup holder onto my lap! What's going on! It feels like it's coming from right in the middle of the car/under the console, and in the rear of the car. Could my transmission mount be busted? What's goin one??

FredoCamaro

iTrader: (18)

I say try the tranny mount

Red97Z

iTrader: (22)

Anyone else? I also noticed some oil around the under carriage of my car, seems to be motor oil . Which leads me to believe that my tailshaft might actually be broken. I replaced my transmission mount about 5,000 miles ago, and recently put on a spohn floor mounted torque arm after my old one was cracked: cracked torque arm+ replaced tranny mount= broken tailshaft that i overlooked??

jmm98LS1

iTrader: (28)

Maybe the driveshaft counterweight got thrown off and is now out of balance? Had that happen to my old fox body mustang. Was smooth as silk until 75mph and then it felt like an earthquake! Had the driveshaft rebalanced and the problem was gone.

ChocoTaco369

i'm gonna say something involving the driveshaft also. if you can feel the vibration through the gas pedal, chances are your driveshaft is offbalance or you may have a bad u-joint.

Red97Z

iTrader: (22)

Yeah, I can really feel it through my gas/clutch pedals. Ok, I think I might just splurge and get a new driveshaft, maybe a CF. How about the oil? Any ideas about that?

ChocoTaco369

are you sure it's motor oil? check the oil pan. it may be something stupid like your oil filter or something leaking, too. i don't know how far back the oil leak is. it could be tranny fluid leaking, too if it's around your tranny mount. so many factors to include. it would be easier with pics.

Red97Z

iTrader: (22)

I will get pics up very soon, i'm almost positive it's motor oil, it's all over my crossover brace on my spohn torque arm, on my y pipe, and tranny.

CamaroSS19

iTrader: (24)

The driveshaft vibration would be there all the time not just at 87mph .

When you shift hard into 2nd do you get a bang on the floor by the console that would be your trans mount

ChocoTaco369

not true. a known problem on LT1 cars was the driveshafts were known to vibrate badly at around 65mph. when brought in to be serviced under wannanty, the fix was an aluminum driveshaft. my driveshaft is steel since i have a 2.73 A4 and it vibrates lightly in reverse and at 5mph. other than that, it doesn't. it's about natural frequencies and damping. if the driveshaft isn't perfectly balanced, your car will vibrate once the frequency of the driveshaft matches a certain frequency of part of the car. in his case, the natural frequency clash may occur at 87mph.

Red97Z

iTrader: (22)

Yes, I do hear a bang, but you see, I cannot tell whether it is the floor mounted torque arm pulling on the floor and distorting the car which makes a clunk, or whether it's the transmission mount, I'm assuming it's the transmission mount though because it's the weak part in the setup I have. By the way, here's the oil I'm talking about that's leaking all around the undercarriage.



bad pic I know