2007 Cadillac DTS Q&A

2007 Cadillac DTS Question: What are case halfs. Can I make this repair myself.

Took car in for oil change and tire rotation. Have prepaid oil changes up to 75000 miles from time I purchased car at which time it had 21000 miles already on it december 2007. Told I need wiper blade, air filter and case halfs are leaking oil. altogether $4200 worth of repairs if done. -
Answer 1
CASE HALFS OF WHAT COMPONET -