on the 87 300D there is are the customary nuts (2) on the edge of the oil filter housing. There is also a bolt that runs down through the center of the oil filter housing. On my 123 it is integral to the top of the filter housing. On the 87 300D, it is a separate bolt.

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81 300D N/A 130K miles (Nelly)
87 300D Turbo 80K miles (The Scalded Dog...because it runs like a scalded dog)
95 e320 Wagon 104K
2003 Sprinter 47K miles.
1999 Tandem Bicycle
One beautiful low miles wife (who likes diesels) (that's my wife holding the sign)

My son and I fixing Nelly's odometer