G.M.truck 700 transmission trouble.

[Skydiver]

My company provided work truck 1988 chevy 1500,350ci,700 overdrive auto 73,000 miles. Does this.

When the truck is going up a slight grade at 1/8 throttle the torque converter will lock then unlock about 4 times a second. This causes great vibration in the cab. It shifts fine. It will do this in 3rd as well as 4th gear. If I apply about 1/2 throttle it smothes out nor will it do this on level roads.

If I slightly apply the brake it stops the shudder. Just feathering the brake I know will take it out of lockup. Any quick fixes?

I don't think the transmission has been serviced properly.

Thanks Tim

 

[danandamy]

I'm reaching back into the memory files here but I believe there is a vacume actuated switch mounted on the firewall on the earlier GM o/d's that control lock up of the converter. That switch is real bad about going out.



dan