2002 Altima SL transmission problem???

[Epic1]

Hi, for a while now when I am accelerating from a dead stop with moderate throttle pressure (read as typical acceleration in city traffic), the transmission seems to slip from 1st into 2nd gear resulting in a jerking sensation that you can feel as the car lurches slightly as the gears slip. If I apply very little pressure to the throttle, the transmission shifts fairly smoothly. If I apply a lot of pressure to the throttle, the transmission shifts much nicer but i can still feel it lurch forward. On another note, I notice this same transmission slipping if I am accelerating then have to let off the throttle and then reapply the throttle in a short period of time (this happens to me typically as I am starting off through an intersection and have to let off the gas as the car in front of me slows down or somebody turns into my lane, then they accelerate again allowing me to accelerate again.) This can get pretty unnerving when you get the sensation that you might stall as a result of the slipping transmission.

Does anyone have any ideas about what could possibly be wrong? If I bring my car to my shop in New York they're gonna try to charge me for everything under the sun unless I have an idea about what the problem is (that way they'll think im a bit car savvy and not try to rip me off.) Please help

[OldmanPurdy]

This is an auto right? cause it is displaying all the signs of a slipping automatic transmission. It could be caused but lots of stuff but the first thing to check would be trans fluid level and if theres any leaks, The user manual will show you the dipstick location/procedure for checking it.