Odd Shaking From Transmission

[Daniel9597]

Hello, I have a 1989 Chevrolet K1500 with a 700-R4 auto trans. In the past few weeks it has developed an odd shaking. Anytime I get above 65-70 miles an hour, the entire truck seems to shake and I can't get it to stop. At first I thought it was tires out of balance, but then it started shaking at other times. It is perfectly smooth until it gets to the top of 3rd gear. Then it'll start shaking and won't stop until I rev it a few times. It also likes to start shaking while I am traveling uphill, and any other time I put it under load, like a fast takeoff from a stoplight. It'll shake, then when I let off the gas and rev it a few times, it'll clear up. Any advice or help is appreciated, and I'll try to provide any other information I need. Thanks in advance.

 

[1500z71]

Hey man, I don't have an answer for you but misery loves company, my '93 has the same symptoms I mean like word for word as yours. I'll try to find my forum. I never got it solved maybe you'll have better luck and this thread will help us both.

Edit: the forum I made
http://www.gmt400.com/threads/truck-shakes-bad-over-60mph.34017/

 

[Daniel9597]

Thank you, 1500z71, that was actually a really descriptive forum. There is a tire shop literally 1/4 mile down the road from my house that's owned by my girlfriend's grandfather, and he should do a tire rotation and balance for less than 20 bucks for me. I'll start with that, then look into the driveshaft weights. Thanks for the help, and I'll keep you posted on how things go. If I figure out what it is then I'll let you know to fix yours, as well.

 

[1500z71]

Thank you, 1500z71, that was actually a really descriptive forum. There is a tire shop literally 1/4 mile down the road from my house that's owned by my girlfriend's grandfather, and he should do a tire rotation and balance for less than 20 bucks for me. I'll start with that, then look into the driveshaft weights. Thanks for the help, and I'll keep you posted on how things go. If I figure out what it is then I'll let you know to fix yours, as well.

Thanks buddy I'll keep checking in in the meantime. We gotta work together to keep these beasts on the road and this site is a great way to do it.

 

[beardeddummy]

If it's driveshaft it should do it in 2 at high rpms too