Oil Pressure Return Tube

D318 SRM shows there should be an oil pressure return tube coming from the center main bearing cap to the oil pump. It is used to control the oil pressure going to the bearings, but I do not have this setup in my engine. There is not even a spot drilled in the bearing cap to attach a tube. Is this anything to worry about?

Thanks

No worry, the oil clutch pump arrangement does not use that center main return.

Was reviewing my oil clutch info and recalling your search for bearings.
I'm wondering if you got the correct rear main that goes with the oil clutch set up. The top section should be three groove, the bottom has two. Oil enters the clutch through groove #3. Bearing lube through groove #1. Groove #2 is common drain.

[quote="Old Magnet"]No worry, the oil clutch pump arrangement does not use that center main return.

Was reviewing my oil clutch info and recalling your search for bearings.
I'm wondering if you got the correct rear main that goes with the oil clutch set up. The top section should be three groove, the bottom has two. Oil enters the clutch through groove #3. Bearing lube through groove #1. Groove #2 is common drain.[/quote]

The bearing hasn't arrived yet, but I ordered it straight out of the parts manual "No. 12 Motor Grader 70D1-4309", part # 5H8021 from my Caterpillar Dealer, so it should be right. Thanks for the info, I will be sure to check it when it comes.