Vehicle recall 79V133000 · May 31, 1979

Mack DM, DMM and 13 more models

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,…

Source: NHTSA data as of September 22, 2026. Last refreshed Sep 23, 2026, 2:43 AM UTC.

Summary: 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.
Remedy: 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.
Notes: Vehicle description: trucks equipped with endt (b) 676, etaz (b) 673A, and etay(b) 673A engines.system: engine and engine cooling.consequences of defect: engine lubricating oil, in the presence of a source ofignition, could lead to an engine compartment fire and serious injury tovehicle passengers.

Recall details

NHTSA campaign: 79V133000
Reported to NHTSA: May 31, 1979
Filed by: MACK TRUCKS, INCORPORATED
Owner notification: November 2, 1979
Vehicles potentially affected: 23,000
Initiated by: NHTSA’s Office of Defects Investigation
Components: Engine and engine cooling › Engine

Recall 79V133000 on nhtsa.gov, with the manufacturer’s documents

Vehicles covered

As listed by NHTSA. A recall usually covers only some vehicles of each model and year, often a production date range.

Mack DM (1977-1979): 1979, 1978, 1977
Mack DMM (1977-1979): 1979, 1978, 1977
Mack F (1977-1979): 1979, 1978, 1977
Mack MC (1977-1979): 1979, 1978, 1977
Mack MR (1977-1979): 1979, 1978, 1977
Mack R (1977-1979): 1979, 1978, 1977
Mack RD (1977-1979): 1979, 1978, 1977
Mack RL (1977-1979): 1979, 1978, 1977
Mack RM (1977-1979): 1979, 1978, 1977
Mack RS (1977-1979): 1979, 1978, 1977
Mack RWL (1978-1979): 1979, 1978
Mack RWS (1977-1979): 1979, 1978, 1977
Mack U (1977-1979): 1979, 1978, 1977
Mack WL (1977-1979): 1979, 1978, 1977
Mack WS (1977-1979): 1979, 1978, 1977

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.

Check your VIN with NHTSA

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.