Joanna**79

I have a 86 700r4 trans. I have a very bad vibration, in gear, in neutral. I had started my engine awhile back for the first time, & it didnt vibrate then, nothing at all. Yes it has sat for awhile, but that shouldnt cause this. The converter is new, I did fill it with fluid before installing it. I need some help. Everyone says its the trans & it needs to be rebuilt. Thanks for your time

mrvedit

If you had said he just bought the car and it had a bad vibration both in gear and in neutral, I would have suggested starting by checking the converter bolts.
We rarely encounter vibrations caused by the transmission on this forum; I'll bet the "everyone" you are referring to don't know much about transmissions.
In Neutral basically only the input shaft, drum and pump are spinning. If the input drum causes vibration due to a problem it likely will "explode" the next time your nail the throttle.
Granted it is strange for a vibration to start from just sitting, but I would first suspect the flexplate, the converter, the front crank balancer and last the transmission.

performabuilt

iTrader: (25)

Note also when you say in gear I assume Brake applied not moving in this situation nothing inside the trans is moving, . So that would point to engine, converter, flexplate and balancer as mentioned .

forcd ind

iTrader: (7)

Is this behind an LS engine? is the snout registered into the crank? unbolt the converter, slide it back and fire it up and see if it still vibrates. I have seen a converter cause a vibration. Also ck for the exhaust hitting the frame or something, you would be surprised how many times that happens and the engine/trans gets the blame, lol