so I tried to refill the bevel gear compartment so I looked under the seat like the copies nige shared on Dropbox (page 17) and I couldn’t find either a fill compartment, dipstick, anything, so I am guessing the fill plug is somewhere in the rear of the dozer. There are three bolts that look like oil plugs but I forgot my toolbox and couldn’t unscrew the bolts other than those plug like bolts I can’t think of any other possibility for where to fill with oil Then I looked into the steering clutches compartment and it had like 6 inches of sludge and engine oil. I couldn’t find drain plugs for those compartments either i must be missing something or do I have to unscrew and remove the battery compartments and the fuel tank I hope not !!!
After reading the documents in acmoc library, apparently the transmission and the bevel gear fill compartments are one and the same in my machine, I couldnt find this compartments in the copies nige shared: I drained the bevel gear oil by removing the bottom plate bolted in the rear bottom part of the dozer like in the photos, but apparently there is a drain plug somewhere like it shows in these photos but I cant figure out of what part of the dozer these photos were taken, do I have to remove the floor plate, or is this hiding below the fuel tank? There is no breather or dipstick for the bevel gear oil in my machine so im assuming I have to look for the transmission dipstick and breather. or maybe this is looking like below the dozer
That photo from the service manual is for a powershift, yours is a direct drive.
I cant edit my original post, so I found in another book this photo So thats where the drain compartments for the oil seepage in the steering clutches compartments. Still no clue on where is the bevel gear refill port, I will check out the gearbox fluid hopefully there will be a dipstick which will read empty and I will know the bevel gear and the transmission fluid compartments share the same refill port hole.
Looking at a 78A parts book in the lubrication capacities, there is no mention of the capacity of the bevel gear, just 7 US gallons for the transmission. Parts manual here -->> https://www.tractorparts.com/PDFs/CAT_D4D_78A.pdf
Thanks for sharing this manual I had forgotten there was a parts manual with diagrams of where everything is located. Yeah I am thinking this is for the automatic transmission and in such case its the same oil shared for both bevel gear and transmission. I am hoping its the same with the manual gearbox, I think it is according to the copies I printed. I will find out where is the bevel gear fillport or the manual gearbox fillport in the parts mnual thanks!
So I found the steering clutch compartment drain plugs they are located under the dozer right under the compartments The bevel gear fluid port is the same as for the manual trans couldn’t refill because I need a one inch square socket