1977 Mack Rm Recalls, Complaints & Specs
6 safety recalls list the 1977 Mack Rm. Check your own VIN below.
6 safety recalls for the 1977 Mack Rm
Most recent first. Recall repairs are free at any authorised dealer. Click a recall for the full defect, consequence and remedy text.
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Engine (engine and engine cooling)
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…
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.
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Interconnecting assembly(wiring) (service brakes)
Delays of up to about 2 seconds may exist in the brake application times to the brakes on the bogie axles in the presence of certain types of wheel speed sensor signal discontinuities or distortions that may occur as a result of sensor wire failure. This constitutes a non-compliance to federal motor vehicle safety standard no. 121, "air…
Remedy: Dealer will install new wheel speed sensors that incorporate improved wiring and the present bogie anti-wheel lock system will be changed to an axle-to-axle system for improved reliability.
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Hanger/bracket (suspension)
A deficiency exists in the welds securing the rear spring insulator bracket to the axle housing. This is due to improper positioning of the weld, in relationship to the bracket and axle housing. Failure of the welds would cause separation of the spring insulator bracket and the axle housing, resulting in improper alignment of the…
Remedy: Dealer will reweld the insulator spring bracket at no cost to owner.
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Fan (engine and engine cooling)
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.
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Anchorage (seat belts)
The involved vehicles do not conform to federal motor vehicle safety standard no. 209, "seatbelt assemblies". Although the seatbelts in question performed marginally with respect to the 5000 lb. Load requirement, additional testing confirmed that the anchor could fail, allowing either the anchor to slip over the hold-down nut or the…
Remedy: Dealer will inspect and, if necessary, replace seat belt assemblies without charge to owner.
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Wheels
The front wheel rim clamp studs, installed on the involved vehicles, may not have been manufactured correctly, causing a brittle condition in the thread root area. The studs could eventually crack and break when wheel nuts are tightened to specifications.
Remedy: The dealer will replace all suspect front wheel studs, without charge to owner.
No owner complaints on file
NHTSA has no owner complaints on file for the 1977 Mack Rm. For context, the average model year in NHTSA's database has dozens; a zero can mean a reliable vehicle, a rare one, or both.
Compare Mack Rm model years
Recall and complaint counts for every Mack Rm model year in NHTSA's database.
| Model year | Recalls | Complaints |
|---|---|---|
| 1972 Mack Rm | 1 | 0 |
| 1973 Mack Rm | 1 | 0 |
| 1974 Mack Rm | 3 | 0 |
| 1975 Mack Rm | 3 | 0 |
| 1976 Mack Rm | 3 | 0 |
| 1977 Mack Rm | 6 | 0 |
| 1978 Mack Rm | 2 | 0 |
| 1979 Mack Rm | 2 | 0 |
| 1980 Mack Rm | 1 | 0 |
| 1981 Mack Rm | 1 | 0 |
| 1982 Mack Rm | 1 | 0 |
| 1983 Mack Rm | 1 | 0 |
| 1984 Mack Rm | 1 | 0 |
| 1985 Mack Rm | 1 | 0 |
| 1986 Mack Rm | 2 | 0 |
| 1987 Mack Rm | 3 | 0 |
| 1988 Mack Rm | 3 | 0 |
| 1989 Mack Rm | 2 | 0 |
| 1990 Mack Rm | 1 | 0 |
| 1991 Mack Rm | 1 | 0 |
| 1992 Mack Rm | 2 | 0 |
| 1993 Mack Rm | 1 | 0 |
Checking a specific 1977 Mack Rm
How do I know if my 1977 Mack Rm has an open recall?
Enter your 17-character VIN above. The VIN is on the driver's side dashboard (visible through the windshield), the driver's door jamb sticker, and your registration or insurance card. The check runs against NHTSA's live database and tells you which campaigns list your vehicle. 6 campaigns currently list the 1977 Mack Rm; your car may already have been repaired under some of them.
Is the recall repair free?
Yes. Under federal law, manufacturers must fix safety recalls at no charge for vehicles up to 15 years old from the date of sale to the first owner. Contact any authorised Mack dealer with your VIN and the NHTSA campaign number (for example 77V096000).
What is the difference between a recall and a complaint?
A recall is a safety campaign filed by the manufacturer or ordered by NHTSA, with a defined defect and remedy. A complaint is a report an owner sent to NHTSA; it is not verified, but patterns of complaints are what trigger NHTSA investigations and, eventually, recalls.
Other Mack models
- Mack28 complaints
- Anthem (an)12 complaints
- Granite (gr)9 complaints
- CXU6127 complaints
- Ch6 complaints
- Gu6 complaints
- CH6005 complaints
- Cxu5 complaints
Source: NHTSA recall and complaint databases and EPA fuel economy data, October 2026. Complaint counts are owner reports to NHTSA, not verified defects. Recall counts are safety campaigns that list this model year; whether a particular car was already repaired depends on its VIN. How this data is compiled.