Transmission slipping

[Soxnation13]

As of late i have been experiencing problems (only in first gear) with what seems to be my transmission. When I am in drive sitting at a light or stop sign the car seems to slip out of gear. The engine will rev and eventually it will catch and the tires chirp as the gears catch but it seems to be happening more frequently. I have had the transmission fluid flushed and filled. This stopped the slipping for a bit but it has recently started back up again. Any ideas what the problem may be and maybe an easy fix or ideas for a fix?

 

[Jeff4runner]

Replace a quart of fluid with a quart of Lucas Transmission Fix. Never had to use on my 4runner, but it did wonders to a Ford E-150. (But, it is a ford after all). In your case, it could either help, or do a little bit. Very safe for older automatic transmissions.