1982 automatic 4sp trans problem

[monte70]

Does anyone know what causes this automatic to jerk hard into reverse from Park or Neutral? Also Neutral to drive. Car not on road but up driveway seams to shift from 1st to 2nd with no problem. Is there a modulator valve on this tranny?:confused

 

[Larry82]

Are you saying there is a noticeable hard shift (some call it a "clunk") when going into Drive or Reverse? More Drive than Reverse? If so, the common problem is the rubber "donut" that the differential sits on. These tend to get old, worn out and torn after 20 years. If it is that, replace with a poly donut bushing. It is a $25 part, but a mechanic probably needs to put it in, as you most likely have to disconnect the driveshaft in order to lift up the differential to get the bushing out and back in. Did mine about 3 months ago. Solved problem.

 

[monte70]

No not a clunk. More like if you have about 3k on the tach, foot on brake, and dump it in gear. Does this if reverse also. But the car is at normal idle.

 

[Ls1smlblck]

On the 700r4, the harsh shifts from P- R and N-D is usually caused by high pressure. If your idle is set right then check your TV cable with the engine off. Pull the cable torwards the front, it should snap back and you can hear it engaging in the tranny. If not, a few good pulls should get it to snap back. This symptom of high pressure is caused by the TV valve sticking in it's bore with the earlier 700r4s. And or if the cable is broken the tranny is goes in High Pressure mode to prevent further damage when going down the road. Pull the pan and push the plunger to see if it moves freely. Also any metal shavings can get in to the bores glogging up valves. Hope this helps.