Hi Eddieb & Josh,
Got my 70D1-up parts manual in the mail today. It does show the oil clutch system and parts, including bell housing, connecting pipe, three section main engine oil pump etc. Also you reminded me that I had an 80C1-up parts book all along but didn't think to look there. It has the parts breakdown also. The 8T1-up parts book I have does not show the oil clutch so maybe in a later edition.

Interesting that the oil clutch is shown as standard (not attachments) on the 70D and 80C models and I suspect the 71D as well. Maybe some folks have it and don't know it????

Anyway thanks for the help.
Getting to know these late graders:)

EddieB,
Got a question on the grader oil pumps.
The early 8T (no oil clutch) has a two section pump, center & end suction.
The 8T14782-up says one of its sections supplies oil to the clutch, another to scavenge. What happens to the double suction for the sump?? or is it a bleed off supply situation. I don't have the matching parts book to check it out.
The 8T16361 and 80C1-up and the 70/71D is pretty clear...one section to supply the clutch, two sections for the sump and windage return for the clutch oil.

OM,
the Serv. Bulletin I just found, May 16 1955 tells of No 12 MG Improvements.
Included is a section on "Oil Flywheel Clutch". Under the "lubrication" section it tells us that :- "the engine is now fitted with a three section oil pump. One section is a scavenge pump which returns oil to the sump from the radiator end of the engine. The center section is an "outlet" pressure regulated oil pump supplying oil to the engine through full flow filters. The third pump, also outlet pressure regulated, supplies oil directly to the oil clutch for cooling and lubrication". The article on the clutch alone is some five and a half pages !!!! No diagrams for the circuits are given and the oil pump is shown assembled. Attached is :- D318 oil pickup in the F/W hsg. using flywheel windage, and D/E oil pump, both from the article.
Similarly the oil pump for the D333 engined No 12 is a special 3 section pump.
Hope this helps,
Cheers,
Eddie B.

EddieB,
OK, I think I got it. Was thinking scavenge pump was for the oil clutch not the radiator end engine sump on the early oil clutch. So they were all flywheel windage and gravity return then, correct?? If so, all pump sections are accounted for. Thanks

OM,
correct, these units are windage to the pickup recess (catch trough) shown in my last post and gravity return through the big tube to the D/E sump.
For dyno testing these D318 grader engines we had a special flywheel adaptor with a big boss to align with a cover with a lip type seal to contain the F/W Hsg. oilflow sent to the not fitted clutch, the F/W Adaptor pretty much sealed of the clutch recess area in the F/W so most pump oil to the cluch would be controlled (dumped) via the relief valve for the clutch section of the D/E oil pump, otherwise the F/W Hsg. would be flooded and the F/W dragging in the excess oil would show up as a low power on the dyno-- from the parasitic load.
Cheers,
Eddie B.

Eddie,
Do the grader flywheels have the oil drain holes in them like the tractors do?

OM,
yes,
I can see a pair of drillings and can't recall, (mid 60's) but I think there would be 3 pairs of the small drillings in the rim, see att. 5 for one pair at 6 O'clock on the F/W rim. There are certainly 3 slots evident in the cover shown in the att. The other att. shows the oil flow (approx. 10 gpm.) through the rear main bearing shells into the flywheel center area. Sorry but bound editions of Serv Buls. and other do not lend themselves to scanning--enjoy.
I think this will help, trying not to use up too much att. availability, so have'nt scanned full 10 att. article, can only scan 1/2 page at a time for clarity..article is 5 pages!!!!
Cheers,
Eddie B.