What is the purpose of recoil spring housing oil in bulldozers? what happens if not filled?
It help to prevent rust on the recoil spring.
Most as with Cat were dry, just a cover across them, Allis and some others had oiled enclosures or grease filled.
I remember a D8K in one of the fleets that I worked on that had oil in the track frames. We found out because of some cracks that leaked.
Good ideas do repeat!!
The coal operation near us dumps their used engine oil in there....
That would just end up nasty. Used engine oil has all manner of contaminants and built up acids that would not bode well in there.