ive read a lot of shaking/vibrating threads on here. almost none are similar. mines no different. ive got an 88 2.8 automatic.

hitting at around 45mph and above the car will get extremely scarey and violent with its shaking. ever seen an earthquake machine go off? its like that. the vibration is seldom at lower speeds or if the car ever hits final gear it wont start shaking until i hit around 60. i can hear a sound similar to if you were to put a marble inside a cooking pot and spin it around the bottom edge. i can rule out a couple of obvious things for a few reasons.

i just did a rear end swap on it on sunday. switched it from an open rear to a posi disc from a 95 trans am. i did this becuase the rear was grinding something fierce and i thought the shaking was a result of a bad rear. i honestly thought the 2 problems were related. well the grinding is gone but the vibration and shaking is still there.

after the swap i had new tires mounted and balanced as well as a wheel alignment.

now for the tranny issues. it has a real hard time in reverse. i cant get it to back out of my driveway without a lot of gas. when i took it for a test drive after the swap i pulled into someones driveway to turn around. it was a very slightly inclined driveway but i had to back out up a hill. the car didnt like that at all. giving it a good amount of gas it wouldnt move. then when i proceeded to cram the gas to the floor i heard a very bad gut wrenching grinding noise. i had to go further down the driveway and turn around in the guys yard so i could get out forward.

the vibrating/shaking will completely stop if i let off the gas, floor it, or if i throw the tranny in nuetral. i actually drive it like this and its very annoying.

checking the tranny fluid it looked like used motor oil and smelled like burnt hair. it was slightly low but not dry. this morning i changed the fluid and filter. new gasket also. no metal shavings. im wondering how its the fluid is burning without being empty.

car has a hard time hitting 2nd and final gears when cold. but when it is cold theres no shaking or vibration. once it drives a couple miles thats when the ride of your life begins. it also has been getting noticeably bad gas mileage since this began.

other than trying to get some insight on whats wrong with it, i have plans in the spring to replace the 2.8 with a 350. would it be easier to just replace the tranny and engine together as a whole unit if the tranny really is on its way out? in which case it needs to last me through the winter. and how fast its degrading im wondering if itll last me through the rest of the month.

 

Sounds like it's already dead.

 

well if theres nothing i can do there nothing i can do.