- The problem
- In the event of turbocharger compressor wheel failure, one or more of the four capscrews that hold the turbocharger together may be struck by parts of the compressor wheel, resulting in the capscrews being damaged. If these capscrews are damaged to the point that they allow the compressor back plate to dislocate from the turbocharger bearing housing, engine lubricating oil may be allowed to escape under pressure, contacting the engine exhaust manifold sections or turbocharger turbine housing.
- The fix
- Dealer will install a shield for the heads of the four capscrews, along with stronger sae 8 grade 8 capscrews, if necessary, at no cost to owner.
Engine & cooling
1977 Mack DMM Engine problems
No owner has filed a complaint about the 1977 Mack DMM's engine & cooling with NHTSA. Stalling, loss of power, oil consumption, overheating, head gaskets, timing chains and engine failure.
- Complaints
- 0
- Recalls
- 2
- Crashes
- 0
- Fires
- 0
- Injuries
- 0
- Deaths
- 0
Engine recalls for the 1977 Mack DMM
- The problem
- 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.
- The fix
- Dealer will replace the original fan with a steel fixed blade fan, free of charge.
Engine complaints
No complaints about this area yet.
Mack DMM engine complaints by year
DMM engine problems, every yearSource: U.S. National Highway Traffic Safety Administration (NHTSA) complaints and recalls, checked . Complaints are owners' own reports and are not verified. How we use the data