Automatic trasmition issue
Thread Starter
Drifting
Joined: Aug 2011
Posts: 1,861
Likes: 1
From: panama panama
Automatic trasmition issue
when I move my shift to drive. the trasmission. make clunking noice and the car jump. same when i move to reverse.
what make my automatic trasmission jump that way and make that bad off a clunk noise
what make my automatic trasmission jump that way and make that bad off a clunk noise
Last edited by hitmanpty; Mar 15, 2013 at 10:05 PM.
Race Director
Joined: Apr 2002
Posts: 10,036
Likes: 346
From: Anaheim CA
That's the way the older 700r4s work. GM upgraded the transmission with an auxiliary valve body in late 1987 to prevent this.
The best way is to shift into N, wait a few seconds, then shift into D or R.
...Or do like I did and replace the old 700r4 with an '89 transmission.
The best way is to shift into N, wait a few seconds, then shift into D or R.
...Or do like I did and replace the old 700r4 with an '89 transmission.
Drifting
Joined: Aug 2010
Posts: 1,704
Likes: 8
I agree with Cliff,there is an excess of pressure build up,on the early 700r4, this cause that bang&jump.The new auxiliary valve body added a new set of accumulator piston to prevent and absorb this pressure,this from 87 with the new 4l60.it's a rough transmission,but i like it .
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Pro
Joined: May 2012
Posts: 519
Likes: 5
Ok man, I was making a joke sorry. You have 6 U-joints (universal joints) located at each end of the drive shaft. Transmission to rear end gear. 2 on each axle. Rear end to hub. The gentlemen suggest you check the U-joints first then follow up with the transmission issue.
Racer
Joined: Jan 2004
Posts: 380
Likes: 0
From: New Hampshire There's nothing like a 'Vette
Check the motor mounts. A broken mount will let the engine and trans shift. Also, you might check and make sure the c-beam bolts are tight. Either of these conditions can cause what you are describing.
