Vibration...

[Intimidatorz34]

I am getting a vibration (the entire engine seems to shake) when I start the car, step on the brakes as its coming to a stop, and when it shifts into whatever gear around 55 mph. I would think it to be a lower engine/tranny mount but not sure why the entire front would shake when it is in this gear. (and its not alignment, etc.) Any Ideas? The upper mount is a new (5k miles) polydogbone. And if it was a tranny, I wouldnt think that it would shake when in park. Then again why is it shaking so bad in that certain gear unless its at a certain resonance.

There arent any codes and the timing belt is fine.

[god910]

The "whatever gear around 55" is your 4th gear. 4T60 shifts like so: 1,2,3,TCC,4 Does the shake go away at a higher speed? If so what is it? If the shake changes w/ speed, I'd say tires. I've even seen brand new tires do it, just a bad tire. (My buddy had 4 sets put on his truck before they got a set that didn't shake. They were pretty cheap, but you get the idea.)

[Intimidatorz34]

I havent had the nerve to go above 60 with the vibration....it suddenly started so I know it isnt the tires, because they havent been touched in 1k miles. Plus the engine is vibrating while it is in park.

[Baddflash]

Hows the engine running?

Possibly trans/conv related, I've heard similar problems and it was broken/missing flex plate/conv bolts.

Is there any problems shifting? If it only does it at higher speeds it may be something with the TC lockup.

:roll: :?:

[Intimidatorz34]

It shifts fine
The motor just shakes when it is in park too.