As I explore what has to be done to my newly purchased 1983 300SD , I have notice a rattling behind the front crankshaft pulley . With a flashlifght it looks like the a metal plate with 10 mm head bolts ( crankshaft seal retainer?) . What is strange is that there is only slight of oil leakage in spite of this being loose . Is there any way to tighten it up easily (vs removing radiator etc and removing the pulley ) ? - Thanks