My '93 940T's automatic transmission is slow to engage after it has sat for several hours. I start the car, put it in gear (forward or reverse) and it slowly starts to move. Once it starts moving, it shifts and runs fine. I just put this transmission in a year ago, so I haven't flushed it yet. It replaced one that had difficulty shifting into overdrive, and I purchased it from an independent Volvo mechanic with a good reputation. Is this type of problem caused by something as simple as a leaky valve, or is it something that is going to get worse and leave me stranded somewhere?