Some of the transmissions had a "warm up regulator" on them which would extend the shift changes until the car warmed up. I don't recall if the 95 C-class had this but it is possible. I would also recommend have the driveline inspected to ensure that none of the components are worn, including, engine and trans mounts, front flex disk, center support and rear flex disk. Worn flex disks will produce slop in the coupling and imitate a hard shift. Has the trans been serviced as scheduled? HTH
92 Volvo 740 Wagon aka "Mutt mover"