B767-300 and 300 ER
Maintenance Airframe; Maintenance Powerplant
Distraction; Fatigue; Situational Awareness
Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Published Material / Policy
General Maintenance Action
Aircraft; Human Factors; Chart Or Publication
I had the Grease [Lube] Work Cards for the Left-hand (L/H) Main Landing Gear (MLG) and the L/H and R/H Pivot Pins.  I accomplished the L/H MLG completely and started the R/H [MLG].  It was very hot; so I took a break. When I came back from lunch I signed the Work Card before finishing the task. Being tired and hot; I became distracted and forgot to finish the Pivot Pins on the R/H gear.  I should take note to follow my task [Work Card] step by step from now on; with all work being accomplished; no matter what it is; [or] how many times I have done a job; and not to sign any work that has not been completed.  Memory lapse.
A Mechanic signed-off a Lubrication (grease) Work Card for the Left-hand (L/H) and Right-Hand (R/H) Main Landing Gears (MLG) and Truck Bogie Pivot Pins on a B767-300 aircraft; after returning from a break for heat and fatigue; without completing the job.