Hello, I got this 977h last fall snd have been slowly tinkering on it. Got to changing the trans fluid, and it looks like the bevel gear drain plugs are gone, but I wanted to double check that this is where they should be:
Not totally sure of the things that look like openings on the bottom but the opening higher up on the left hand side of the photo looks like the filler opening for the left hand final drive gears. I kind of thought that the actual bevel gear drain would be further forward under the machine and maybe closer to dead center on the width of the machine. If you post your serial number, a kind soul on this board may tell you how to download service literature direct from Cat--the price is not bad for a digital download; for a paper copy, it gets stupid expensive. Good luck and we need photos! Jon.
I found the drain at the bottom, I was thinking the open holes were the overflow drain that starts leaking when you reach the right fluid level. Theres a bunch of greasy sludge in the bottom of the bevel gear, as well as in those mystery holes if I stick my finger up there, thinking dirt got in through those holes for as long as the previous owner was operating it without those plugs in.
Any ideas on a good way to clean sludge out of the bevel gears without taking them apart would also be greatly appreciated! like a solvent that is safe to pour in there and then drain out?
Im probably using the wrong terms for the parts im talking about, so I apologize for my ignorance. I believe those drain plug holes with no plugs are for the bevel gear. I was previously thinking they were overflow plugs for the steering clutches
To come up with an illustration for the bevel gear case is S/N-dependent. There are half a dozen different illustrations but which one is the correct one is the question.
On my D7C, I think those are a drain for the brakes maybe to drain off water and or oil that got into the housing.
Leaving the fill plugs out.....that's trouble, at least it wasn't driven through a creek. My machines have about 7 gallons in the finals. We had a very old mill in the shop that for oil change the manual said drain and fill with kerosene run unloaded for an hour drain and refill. "No warranty on this idea"!!!! I assume we do this only with the finials and don't do it to long it might make the seals leak. Block up machine (put the bucket down edge first to raise front a couple feet use 2x4 to roll a 3' long x big enough diameter to raise machine a few inches, put another log in front and set it down) drain and fill with diesel run in low for awhile drain maybe filter with coffee filters and maybe and go again. Get a big tray for all that oil. Maybe raise it higher.
I have a K model 977, if you have a late model H it might be the same; it may also be hidden behind a lot of mud and crap. look in the underneath center rear of the bevel gearbox(very back end housing of the machine)-the bevel gear drain plug is right in the middle,I think it was 3/4"square drive plug,(try a 3/4"ratchet with extension)..if you're gonna pop that plug get ready for a tidal wave because its like 40gallons of crude comin at ya if she's full. As said by Cat977, I'd use kerosene as well,it cuts crud pretty well..hard to find it this winter, something I heard that they stopped production of it for some reason.Expensive at the least.Best of luck