Full explanation
Principle: a conventional bolt is tightened by torque only (Nm), while a TTY bolt uses torque + angle (e.g. 30 Nm + 90° + 90°). The result is uniform clamping at 85–95% of yield strength, compensating for gasket creep under heat. Applications: (1) cylinder heads in modern Stage IIIB/V diesels (John Deere PowerTech, Cummins QSB, FPT NEF); (2) con-rod caps; (3) flywheels. Reuse risk: head life drops 20–40% and gasket blowout probability rises 3–5× [VERIFY]. OEM kit price (John Deere 8R, Case IH Magnum): UAH 2,800–4,500 for an 8–14-bolt set [VERIFY]. Workshop manual signal: "replace after each removal" or "use new bolts." In Ukrainian service shops, reuse is a common cause of post-repair failures. Required tool: an angle gauge (Snap-on, Wera, or budget Hofmann UAH 180–600).