I have a Poulan model PO17545ST with a 42" cutting deck. Recently I had to replace the mandrel on the left side. The deck now cuts unevenly . My
question is " what is the procedure to adjust the deck height so both blades cut at the same height?"

Hi,
See if this helps(for side-to-side.)
http://www.poulan.com/ddoc/POUO/POUO2003_USen/POUO2003_USen_188870_.pdf
Peace,
Clarke