Axles
The two major suppliers of heavy-duty drive axles for Class 8 trucks, and how their model numbers match real weight ratings.
Meritor
MT-14X
Meritor's flagship highway tandem drive axle. It competes directly with Dana Spicer's D-46-170HP.
GAWR range
40,000–46,000 lb
Configuration
Tandem drive, hypoid gearing
Meritor markets the MT-14X as roughly 50 lb lighter per axle than the equivalent Dana axle. Across a tandem set, that's real payload capacity, not a rounding error.
Dana (Spicer)
D172 Series (D40/D46/D50-172)
Dana's heavy-duty tandem drive axle family, sized by rated capacity. D40, D46, and D50 match roughly 40,000, 46,000, and 50,000 lb GAWR.
GAWR range
~40,000–50,000 lb depending on model
Configuration
Tandem drive
The model number pattern (D40, D46, D50) is a quick way to read the rated capacity. You can read it straight off a spec sheet or axle tag. You don't need a separate chart.
More truck specs
Spec'ing axles for your next truck? Let a dispatcher help.
Grow Trucking finds loads, negotiates rates and does the paperwork for owner-operators and small fleets. Tell us about your truck and we will show you how its axles fit the freight we book.
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Frequently Asked Questions
What does an axle's GAWR rating actually mean?+
GAWR (Gross Axle Weight Rating) is the maximum weight that specific axle is rated to carry safely. It is one of the numbers that sets your truck's overall GVWR, along with the front axle and frame rating. Going over it is both a safety issue and a roadside inspection violation.
How do I know which axle rating I actually need?+
It depends on what you haul. General dry van freight rarely needs more than a 40,000 lb tandem rating. But if you regularly run near 80,000 lb gross with dense freight (steel, machinery), a 46,000 lb or higher tandem gives you more margin.
Axles specs show common current factory options. They can change by model year or region. Always confirm exact figures on the manufacturer's current build sheet before you buy or plan maintenance.
Free tools for your truck
Decode a VIN, look up fault codes and keep service on schedule for the axles on your truck.
- VIN Decoder & Recall CheckDecode any truck VIN and check NHTSA recalls for the model you are reading about in axles.
- Diesel Fault Code Lookup (SPN/FMI)Decode the SPN/FMI fault codes your truck reports on a axles problem.
- Preventive Maintenance SchedulerTrack service intervals by odometer, including axles items.
- Breakdown Cost EstimatorEstimate what a axles breakdown costs in repairs and lost revenue.