Vehicle recall 77V173000 · October 12, 1977
Mack CF, DM and 12 more models
The flex blade fans on the involved vehicles may develop cracks in the laminated stiffener as a result of fatigue during operation.
Source: NHTSA data as of September 22, 2026. Last refreshed Sep 23, 2026, 2:43 AM UTC.
- Summary
- The flex blade fans on the involved vehicles may develop cracks in the laminated stiffener as a result of fatigue during operation. If such a condition exists and the cracks go undetected, continued operation could cause pieces of the stiffener to break off.
- Remedy
- Dealer will replace the original fan with a steel fixed blade fan, free of charge.
- Notes
- Vehicle description: trucks equipped with six-cylinder engines.system: engine cooling; fan.consequences of defect: broken pieces can be propelled outside of the fanshroud and will present an immediate danger and possible injury to personsstanding nearby.note: prior to correction, vehicle should not be serviced with the hood raisedand the engine running.
Recall details
- NHTSA campaign
- 77V173000
- Reported to NHTSA
- October 12, 1977
- Filed by
- MACK TRUCKS, INCORPORATED
- Owner notification
- March 23, 1978
- Vehicles potentially affected
- 48,000
- Initiated by
- NHTSA’s Office of Defects Investigation
- Components
- Engine and engine cooling › Cooling system › Fan
Vehicles covered
As listed by NHTSA. A recall usually covers only some vehicles of each model and year, often a production date range.
- Mack CF (1972-1977): 1977, 1976, 1975, 1974, 1973, 1972
- Mack DM (1972-1977): 1977, 1976, 1975, 1974, 1973, 1972
- Mack DMM (1972-1977): 1977, 1976, 1975, 1974, 1973, 1972
- Mack F (1972-1977): 1977, 1976, 1975, 1974, 1973, 1972
- Mack FL (1972-1977): 1977, 1976, 1975, 1974, 1973, 1972
- Mack FS (1972-1977): 1977, 1976, 1975, 1974, 1973, 1972
- Mack HMM (1972-1977): 1977, 1976, 1975, 1974, 1973, 1972
- Mack R (1972-1977): 1977, 1976, 1975, 1974, 1973, 1972
- Mack RD (1972-1977): 1977, 1976, 1975, 1974, 1973, 1972
- Mack RL (1972-1977): 1977, 1976, 1975, 1974, 1973, 1972
- Mack RM (1972-1977): 1977, 1976, 1975, 1974, 1973, 1972
- Mack U (1972-1977): 1977, 1976, 1975, 1974, 1973, 1972
- Mack WL (1972-1977): 1977, 1976, 1975, 1974, 1973, 1972
- Mack WS (1972-1977): 1977, 1976, 1975, 1974, 1973, 1972
Has your Mack been repaired?
Recalls here come from NHTSA’s records for the model and year. Not every vehicle of a model is included in every recall, and this site can’t see whether a repair has been done. Only a VIN lookup can tell you that.
NHTSA’s VIN search doesn’t show recalls that were already repaired, recalls more than 15 years old, or some small manufacturers’ recalls. A Mack dealer can also check your VIN. Recall repairs are free.