- The problem
- The pitman arm retaining nut may not have been torqued to manufacturer specifications. This could result in inadequate retention of the nut at the output shaft, allowing the pitman arm to become loose.
- The fix
- Dealer will inspect and retorque pitman arm, if necessary, at no cost to owner.
Vehicle safety record
1978 Mack WL Problems, complaints & recalls
No owner complaints about the 1978 Mack WL have been filed with NHTSA. It is covered by 5 recalls, the latest in June 1979 for the linkages.
NHTSA data checked
CAbout as many problems as a typical WL year, for its age
- Complaints
- 0
- Recalls
- 5
- Crashes
- 0
- Fires
- 0
- Injuries
- 0
- Deaths
- 0
1978 Mack WL recalls 5
Recall repairs are free. Your dealer fixes them whether or not you bought the car there - check your VIN at nhtsa.gov/recalls to see if yours is done. What to do
- 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.
- The problem
- 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 brake systems".
- The fix
- 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.
- The problem
- The possibility exists that the aluminum engine rear support brackets may fail due to metal fatigue. This type of failure would allow the engine and transmission assembly to dislocate downward. This will result in throttle control loss with the engine operating continuously in the mid to upper range of the governed speed range.
- The fix
- Dealer will inspect and, if necessary, replace aluminum support brackets with brackets made from ductile iron for increased strength.
- The problem
- A design deficiency exists in the air dryer piping in the area of the pressure relief valve and compressor governor control link. Moisture is passed and builds up in this relief valve and control line. In freezing ambient temperatures, this moisture may freeze, allowing the chassis air system pressure to exceed 150 psi. Excessive air system pressure can cause separation of air piping connections and air system valve failure.
- The fix
- The dealer will relocate the air system compressor governor line and pressure relief valve to eliminate moisture accumulation.
What owners say
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No complaints about the 1978 Mack WL yet
No owner has filed a complaint about this vehicle with NHTSA. If yours has a problem, share it here and report it to NHTSA.
Mack WL: every year compared
All WL years1978 Mack WL vs rivals
| Vehicle | Complaints | Recalls | Grade | |
|---|---|---|---|---|
| 1978 Mack WL | 0 | 5 | C | |
| 1978 Mack Mack | 2 | 3 | D | Compare |
| 1978 Mack RD Series | 1 | 1 | C | Compare |
More sales usually means more complaints, so compare similar vehicles of the same year. The grade compares each vehicle with its own model's other years.
Questions about the 1978 Mack WL
Does the 1978 Mack WL have any recalls?
Yes - NHTSA lists 5 recalls for the 1978 Mack WL: linkages (June 1979); engine (May 1979); interconnecting assembly(wiring) (October 1978); engine (August 1978) and more. Recall repairs are free at any authorized dealer. Enter your VIN at nhtsa.gov/recalls to see whether yours has been fixed.
How many complaints has the 1978 Mack WL had?
None have been filed with NHTSA so far.
Is the 1978 Mack WL a reliable vehicle?
Its Safety Index is 57 out of 100 (grade C: about as many problems as a typical Mack WL year, for its age). The index weighs complaints, crashes, fires, injuries, deaths and recalls against how long the vehicle has been on the road, compared with the same model's other years. It is not a measure of every repair - read the complaints and owner experiences, and have any used vehicle inspected before you buy.
What should I do if my 1978 Mack WL has a problem?
If it is a safety problem, stop driving it if it is unsafe and contact your dealer. Report it to NHTSA at nhtsa.gov/report-a-safety-problem - enough reports start investigations and recalls - and share your experience here so other owners know what to look for.
Source: 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