MacDon FD75 OM - Manual (Page 352)

MAINTENANCE AND SERVICING
4. Adjust the idler roller ‘Y’ as follows:
a. Loosen nut (A) and jam nut (B).
b. Turn adjuster nut (C).
5. If the draper does not track at the idler roller end after
adjusting the idler roller, the drive roller is likely not
square to the deck. Adjust the drive roller, and then
re-adjust the idler roller.
Figure 6.169: Idler Roller
169894 338 Revision A