Hard shifting on auto

Have 86.5 automatic 928S with >78,000 on the clock. Replaced the center drive shaft and torque converter and now experiencing hard shifts on all ranges except fourth. How can this be adjusted out for a smoother shift?

Walt

when was the fluid last replaced? level?

First thing to do is to check the Vacuum Modulator, which is the unit that controls the firmness of shifts.

Find the modulator - a pie-pan-shaped device on the left side of the transmission, with a vacuum line attached. Pull the vacuum line, crank the engine, and check for manifold vacuum on the line. If there is no vacuum (the most likely cause for your problem), check at the back of the engine compartment for a disconnect in the line.

Fluid is correct level, was changed about 20,000 miles back.
The modulator is on the driver side, correct?

Walt

"...on the left side of the transmission..."

For left-drive cars, yes. Not in the UK, Japan, etc.

My 86.5 does not have a vacuum modulator as you described. Tried to attach a few pictures of the transmission showing both sides with no luck. Doing something wrong.
Will try again.

Walt