This is the best investment of PM (preventative maintenance) you can do for your tank.
It is not just one "greasing" step. All gearboxes need to be oiled, lubed and covered for proper preventative maintenance. On a used tank it is 1) Clean, 2) apply machine oil, then 3) grease/lube. The first step is to peel back my TU/gearbox cover and remove the dark old grease. Use no solvents or wire brushes. Use Q-Tips and gun cleaning patches (Hoppes)/small rags on tweezers. Clean them thoroughly at least once a year. Then use a fine machine oil (never WD40) to oil the shafts and bearings. Singer sewing machine oil is my favorite. It has good capillary action to get under the gears where grease will not. Several drops on the shafts near each gear and the end bearing/bushings. Then turn the tracks by hand (DO NOT RUN THE MOTORS...FIRE HAZZARD) to work in the oil. Then spray in (if you have aerosol can with long red applicator tip) or brush in, white lithium grease on the faces of all the gears. The white lith. grease grows darker with age & use. Then turn the motors by hand to work in the grease evenly. DO NOT RUN THE MOTORS. Then reinstall the TU covers adding extra or new tape where needed. I try in incorporate a clear piece of plastic into each TU cover whenever possible. That allows for a quick inspection without removing the TU covers. Jeff and I both seal the TUs at the out-put shafts with foam whenever possible.
Be sure the motor & other wires are neat and safely out of the way from rubbing or shorting out. If I build it they should be very secure...but things move sometimes. This should be done once or twice a year dependent upon use. Add extra grease before each battle. The large plastic gears spin fast and are under low stress/torque so they are made of plastic. The middle/intermediate gears and under more stress but rotate slower so they are made of brass. The final gear on the out-put shaft is hi stress/torque but very slow speed so it is made of iron/steel. All need BOTH oil (shafts & bushings) and grease (gear faces).
Here are some pix for your reference Shannon. The first 4 pix
may be of your tank when I prepped it for you last year.
Tamiya Tiger I
Tamiya KV 1 Out-put shafts seal:
Hooben Elefant:
Tamiya Sherman:
Taigen Tiger I:
H L Stug/Pzr IV converted to Tamiya IR:
Tamiya Pershing:
Tamiya Panther:
Here is how my Danville loaner M4 Sherman looks after a few months on the battlefield. You can see the accumulation of dust & dirt and how it clings to oily surfaces.
Here my covers have been pulled back and you can see how the dirt has not entered the TUs by the top or thru the out-put shafts seals that I use.
Just clean out some of the old and add some new oil then grease and you will have trouble free TUs for years to come.
This is the best investment of PM (preventative maintenance) you can do for your tank.