Just info for anyone working on 4020 tail lights (maybe 3020 also). The original electrical terminals that go through the light body have screws on both sides and were rusted and busted. Went to buy new ones from JD. The parts catalog drawing isn't real clear and it crosses to a different number for replacement. The actual part I got is a rubber grommet which would be workable IF it was the right size but it isn't even close. JD's new part number is R1134R but don't buy as it WON'T fit. I measured the hole at.43 inch dia and panel thickness at .20 inch. The panel thickness is large because there is a lip pressed inward. I'll order correct grommets from Digi-Key
Hope this helps someone to avoid frustration.
Hope this helps someone to avoid frustration.