2001 Ford Taurus Harsh Neutral to Drive

2001 Ford Taurus automatic with 55kmiles. When shifting to drive transmission jerks, it gets worse as car warms up. But once in drive transmission shifts in all speed smoothly also neutral to reverse with no problem. On a hill the car can coast on neutral about 15' then shift to drive and no jerking motion. Is the valve body serviceable without dropping the tranny? Tech Manual talk about engagement control valve,neutral-drive accumulator and oil pressure could be the problem. Transmission shop said it will cost between $1300- 2000 to repair.Any ideas
Thank you for your help.