My machine is fairly new and I greased the TWO Zerks on the drive shaft yesterday first time. The drive shaft exits the rear center of the engine and courses the short distance to the hydraulic pump, the two U joints are within a few inches of each other. From the left side of the frame reach under the radiator to find the drive shaft. The Zerk fittings rotate with the universals and you have to get them pointing directly to the left. I did it by bumping the starter motor. Once you get them pointing toward you, they will still be pretty well hidden from sight, I did not even try to see them. Just go by feel. Now, grease gun flex hoses, being what they are, are slippery. So wipe the coupler and feed it under the hydraulic lines and contort your right hand to press the coupler onto the front Zerk and hold it. That leaves you one handed to pump the grease gun, the trigger grip type of gun is good for that. One pump will do, I could not resist two. The rear Zerk is under the debris cover at rear of radiator. You will again be going by feel as you will be reaching through a slit opening in the loosened vinyl cloth. The Zerk will be facing left just as you left the front one. Same procedure, right hand holds the coupler on the Zerk and left operates the gun.
I had more trouble, or at least as much, in finding and servicing the two Zerks at the front lift pivots.
prs