This is probably an old duplicate question but it's new to me. I saw a service bulletin dated June of 1990 that said the grease fittings for lift cylinder trunnion outer races for the 450C and 850D dozers had been removed and replaced with plugs. It said do not lubricate these points. What about earlier machines that came with the grease fittings? Should you remove the zerk and discontinue greasing or are the new machines built differently? The fitting is in the race that is welded to the heavy shroud at the front. It's like a big ball bearing and has 3/4" balls. There are two other fittings on each side called the lift cylinder inner trunnion that you are supposed to continue greasing.
These? 850D: 450C:
It's only taken 2 1/2 months to reply lol. The pic in the bulletin looks like the 850D and the zerk fitting is the one at the bottom of your blue circle. On my 450C, there are two fittings that lubricate for the swivel movement from side to side and one fitting that lubricates for the up and down rotation. I can't imagine not lubricating that one. I'm confused.
Lubricate every moving joint and do it often. My '87 450C has four fittings in that area on each side, two on the large trunion and two on the pivots for the cylinder mount. IMHO the 50hr service interval is too long on all the blade related fittings on these dozers. When I first got mine I tried that and at 50hrs the joints were either dry and squeaking or the grease hard enough you could barely force new grease in. I now grease them every 10hrs, just like you would most any loader, hoe, etc. I think mfg's past and present try to push service intervals longer and longer as a 'selling point' for new models, I don't listen.