The other day I was doing an inspection underneath my ML320 and noticed a cross-frame member with an oil film on it. I started to become concerned since I thought I had an oil leak somewhere but on further inspection I could not find anything that appeared to be leaking.

The part in question is a rectangular steel cross-member that sits immediately beneath the transaxle. The part has a label with UPC symbols and the word "SAE 90" as this is the lube that should be used. Immediately behind this member are the torsion springs and attached to this member and protruding forward are round steel (approx. 1-1/2 in.) bars on each end.

Is the oil film on this member from the SAE 90 oil? Is this normal? I know that on some early ML's the transfer case has leaked oil but this does not appear to be the case in this instance. Also, the oil film tracks on the round steel members protruding forward of this member.