TM 9-2320-361-34 15-38. BORING CASE MAINTENANCE (Contd) NOTE Ensure that heel of second reduction drive pinion and toe of second reduction feed pinion are alined with toe of rack drive gear and rack feed idler gear. If depth of second reduction drive and feed pinions are misalined, adjust by removing or adding shims (para. 15-42). 14. Working through inspection hole (12), place dial indicator against rack drive gear (13) and measure backlash between rack drive gear (13) and second reduction drive pinion (16). Backlash should be 0.008-0.022 in. (0.20-0.56 mm). 15. Place dial indicator against rack feed idler gear (14) and measure backlash between rack feed idler gear (14) and secondary reduction feed pinion (15). Backlash should be 0.011-0.022 in. (0.28-0.56 mm). NOTE Boring gear must be removed from boring case and disassembled in order to adjust the backlash of rack drive and idler gears. (subtasks a, b, and c). .If backlash is within limits, proceed to step 20. If backlash of rack drive gear is incorrect, perform step 16. If backlash of idler gear is incorrect, perform steps 17 and 18. 15-141