transmission problem

[Benz Dr.]

1970 280SL auto

Trans shifts up and down, kick down works, but it has a very harsh up shift. Down shifts are very smooth. Everything else works.

Any ideas would be welcomed.

[clunker]

Given the asymmetry of harsh shifts up versus smooth shifts down, is the torque convertor a possible issue?

[ja17]

I never had a torque converter cause these issues.Make sure the linkages are free and working along with the three position solenoid. I would check the modulator pressures at all three posi
tions with a gauge next.