Mile Marker 423
An older six-bolt pattern. Check the mounting-circle diameter and spline count together.
Mile Marker Manual Locking Hubs: Splines & Bolt Circle Guide
Mile Marker manual locking hubs differ in their mounting style, spline count and axle size. The comparison below covers six exact models in our catalog and shows why appearance or a broad vehicle description is not enough to choose an installation-ready replacement.
Spline and bolt-circle comparison
Dimensions are in inches. āInternalā refers to the mounting arrangement in the manufacturer specifications, not a missing measurement. The vehicle still needs to match the complete manufacturer application.
| Part number | Spline count | Axle outside diameter | Bolt circle / pattern | Mount type |
|---|---|---|---|---|
| 423 | 19 | 1.250 in | 6 on 3.750-in circle | Six-bolt external |
| 426 | 27 | 1.210 in | Internal design | Internally mounted |
| 427 | 23 | 1.016 in | 5 on 4.500-in circle | Five-bolt external |
| 428 | 27 | 1.206 in | 5 on 4.500-in circle | Five-bolt external |
| 457 | 27 | 1.187 in | 6 on 3.437-in circle | Six-bolt external |
| 449SS | 30 | 1.312 in | Internal design | Internally mounted |
Examples of manufacturer-listed applications
- 423: Selected early Jeep J20, Chevrolet K20 and other listed 6-bolt front hubs.
- 426: Ford Ranger 1998ā2000; Mazda B3000/B4000 2001ā2008, per the application list.
- 427: Ford Bronco II 1983ā1990; manufacturer lists nut kit 95-27988.
- 428: Selected Ford Ranger 1983ā1997 and Explorer 1990ā1994; nut kit 95-27997.
- 457: Selected Jeep CJ 1972ā1986, Wagoneer and International Harvester fitments.
- 449SS: Selected Dana 50/60 applications, including specific Ford HD pickups; kit may be required.
Check required conversions. Mile Marker specifies 95-27988 for listed 427 Bronco II installations and 95-27997 for listed 428 Ranger/Explorer installations. Some 449SS installations require spindle-nut conversion kit 95-32721, while others do not. The full vehicle and hub configuration determines the requirement.
Check these details before ordering
- Axle splines: count and identify the mating shaft; 23 and 27 splines are not interchangeable.
- Axle diameter: match the hub's specified diameter as well as the spline count.
- Mounting: check internal versus external construction, bolt count and measured bolt circle.
- Vehicle configuration: confirm make, model, year, axle and original automatic/manual hub arrangement.
- Installation hardware: check whether a model-specific spindle-nut conversion is required. A visually similar hub or matching vehicle name does not guarantee a direct fit.
Find the matching Mile Marker products
Each card links to the exact NewRVParts product. Items are sold online from supplier warehouses; in-person viewing and pickup are unavailable.
Mile Marker 426
The Ranger/Mazda internal-mount design; a 27-spline count alone cannot confirm fit.
Mile Marker 427
A five-bolt pattern with fewer splines than model 428; verify the required spindle conversion.
Mile Marker 428
Shares a five-bolt circle with 427, but uses a different spline and axle dimension.
Mile Marker 457
A smaller six-bolt circle than 423. Match all measurements and the vehicle setup.
Mile Marker 449SS
Thirty-spline stainless locking hubs used on several heavy-duty axle applications.
Related parts reference
Replacing only service components or converting spindle hardware? See Mile Marker service and conversion kits. Follow the manufacturer's procedure for the exact hub during installation.
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