The Mechanic said The reason for my hard shifting is probably the result of a leaking vacuum line going to the tranny. But I can't seem to find it,can anyone point me in the right direction?


98 SLE

From the throttle body, you will see a couple vacuum lines coming off of it. 2 of them will be a rigid line that goes down to the right side of the engine bay. One will branch off to the round modulator.

In the picture, the modulator is circled in yellow. You can see a little nipple on top of it. Just follow the line connected to that all the way back up to the throttle body.

Doesn't a 98 have a 4t65e transmission? No vacuum line on that transmission. The vacuum line is on a 4t60 transmission.

98 was the first year of the fully electronic trans (4T65) with the NA motor. The harsh shifting is likely caused by the EPC soleniod or another issue.

I would get the car scanned, several of the transmission codes will not trip a SES light.