I had to replace 3rd 4th shifter fork recently, put it all back together and drives ok but when the rpm's are low and the motor is chugging in gear i can hear a rattling sound coming from the gears in the tranny. What could this be and what do i do to fix it? its my only car and cant afford to lose it!

 

I think it would be hard to determine the noise was coming from the transmission while driving the car since it could be coming from the drive shaft CV joints, transmission mount worn out, motor mounts worn out, or even the exhaust system caused by a vibration. Gears can't actually rattle because they are meshed together. Did you check the transmission oil? You could have a leak. Be sure before you start messing with the transmission again. If it is the transmission, I would just get a used one from a pull a part type place where they are only about $80.00 and if it is bad, you can switch some parts or take it back for a credit and get another one.