Coldwar,

So you finally believe us that the disc is a filter, not a spacer. If its not installed, most of the oil will go to the engine unfiltered.

Yes, that's another danger of going to Jiffy Lube with a MB.

Yes, just W115 and earlier MB Diesels used this type of 2 stage filter. When the filter was moved to the top of the engine, the cartridge was changed to a 2 in one filter that did the same thing as the 2 separate pieces you have.

THe cartridge would plug up first because it traps the smaller carbon particles that go thru the disc filter and there would be no indication of htis. If the disc filter ever plugged up, you would have little or no oil pressure.

P E H