The Ultimate Axle Identification & Specification Guide

Axle Identification & Specification Guide
Dana, GM, Ford, Rockwell
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Ultimate Axle Identification & Spec Guide
Dana 30
Overview: The Dana 30 is a light-duty front axle commonly used in Jeep Wranglers and Cherokees.
Specifications:
- Ring Gear Diameter: 7.12"
- Spline Counts: 27 (early), 30 (later)
- Bolt Pattern: 10 bolts
- Axle Shaft Diameter: 1.16"
- Weight: ~124 lbs
- Common Applications: Jeep YJ, TJ, XJ
- Typical Bolt Pattern: 5x4.5 (Jeep TJ/XJ), 5x5.5 (older models)
Identifying Features:
Compact housing, 10-bolt cover, low pinion in early models, high pinion in later XJ/TJ.
Generational Differences:
- Pre-1990s: 27-spline shafts, small u-joints, drum brakes.
- Post-1990s: 30-spline shafts, larger u-joints, improved knuckles.

Ultimate Axle Identification & Spec Guide
Dana 44
Overview: The Dana 44 is a mid-strength axle used in a wide range of front and rear 4x4 applications.
Specifications:
- Ring Gear Diameter: 8.5"
- Spline Counts: 30, 33
- Bolt Pattern: 10 bolts
- Axle Shaft Diameter: 1.31"
- Weight: ~150 lbs
- Common Applications: Jeep Rubicon, Ford Bronco, Scout, FSJ
- Typical Bolt Pattern: 5x5.5 (Ford/Dodge), 6x5.5 (GM), 5x4.5 (Jeep)
Identifying Features:
Stronger than Dana 30, oval 10-bolt cover, used in both front and rear.
Generational Differences:
- Early Models: Two-piece shafts, drum brakes.
- Modern Versions: One-piece shafts, disc brakes, better seals and knuckles.

Ultimate Axle Identification & Spec Guide
GM 14-Bolt
Overview: The GM 14-Bolt full-float axle is a heavy-duty axle known for simplicity, strength, and affordability.
Specifications:
- Ring Gear Diameter: 10.5"
- Spline Counts: 30, 35
- Bolt Pattern: 12 bolts
- Axle Shaft Diameter: 1.5"
- Weight: ~250 lbs
- Common Applications: 3/4 and 1-ton GM trucks
- Typical Bolt Pattern: 8x6.5
Identifying Features:
Massive full-float hubs, removable pinion support, squared diff cover.
Generational Differences:
- Pre-1990s: Coarse spline, drum brakes.
- Post-1990s: Fine spline, optional disc brakes, upgraded hub design.

Ultimate Axle Identification & Spec Guide
Dana 60
Overview: The Dana 60 is a heavy-duty axle used in both front and rear configurations in 3/4 and 1-ton
trucks.
Specifications:
- Ring Gear Diameter: 9.75"
- Spline Counts: 30, 35, 37
- Bolt Pattern: 10 bolts
- Axle Shaft Diameter: 1.41"
- Weight: ~300 lbs
- Common Applications: Ford F-250, Dodge Ram 2500, Chevy 2500
- Typical Bolt Pattern: 8x6.5 (GM/Dodge pre-1998), 8x170mm (Ford post-1999)
Identifying Features:
Large differential housing, kingpin or ball joint versions, full-float or semi-float configurations.
Generational Differences:
- Pre-1992: Kingpin style, coarse spline shafts.
- Post-1992: Ball joints, fine splines, updated knuckles and brakes.

Ultimate Axle Identification & Spec Guide
Dana 70
Overview: The Dana 70 is an extra heavy-duty axle designed for severe-duty applications and used primarily
in rear axles.
Specifications:
- Ring Gear Diameter: 10.5"
- Spline Counts: 23, 35
- Bolt Pattern: 10 bolts
- Axle Shaft Diameter: 1.5"
- Weight: ~380 lbs
- Common Applications: Dodge Ram 3500, Ford F-350, commercial trucks
- Typical Bolt Pattern: 8x6.5 (older), 8x170mm (Ford)
Identifying Features:
Massive ring gear, heavy-duty pinion, full-float hubs, similar cover to Dana 60 but deeper housing.
Generational Differences:
- Early Models: 23 spline, drum brakes.
- Later Models: 35 spline, disc brakes, improved bearings.

Ultimate Axle Identification & Spec Guide
Dana 80
Overview: The Dana 80 is a high-capacity rear axle found in 1-ton and commercial-grade trucks.
Specifications:
- Ring Gear Diameter: 11.25"
- Spline Counts: 35
- Bolt Pattern: 10 bolts
- Axle Shaft Diameter: 1.55"
- Weight: ~420 lbs
- Common Applications: Dodge Ram 3500, Ford F-350/450
- Typical Bolt Pattern: 8x170mm (Ford), 8x6.5 (GM/Dodge)
Identifying Features:
Extra-large differential housing, full-float only, disc brakes standard in later models.
Generational Differences:
- Pre-1999: Drum brakes, coarse splines.
- Post-1999: Disc brakes, refined gear cuts and bearing surfaces.

Ultimate Axle Identification & Spec Guide
Rockwell 2.5 Ton
Overview: The Rockwell 2.5 Ton is a military-spec top-loading axle known for extreme strength, used in
tactical trucks.
Specifications:
- Ring Gear Diameter: 13"
- Spline Counts: 16, 20
- Bolt Pattern: 12 bolts (large pattern)
- Axle Shaft Diameter: 2"
- Weight: ~750 lbs
- Common Applications: M35 Deuce-and-a-Half, custom off-road rigs
- Typical Bolt Pattern: 6x8.75 (Military pattern)
Identifying Features:
Top-load differential, large cast housing, pinion offset design, massive components.
Generational Differences:
- Military Spec: Designed for 6x6 trucks, all drum brakes.
- Civilian/Modified: Often converted to disc brakes, used in mud trucks and buggies.

Ultimate Axle Identification & Spec Guide
Ford 8.8
Overview: The Ford 8.8 is a mid-duty rear axle found in many Ford vehicles, known for strength and
availability.
Specifications:
- Ring Gear Diameter: 8.8"
- Spline Counts: 28, 31, 34
- Bolt Pattern: 10 bolts
- Axle Shaft Diameter: 1.29"
- Weight: ~175 lbs
- Common Applications: Ford Explorer, Mustang, Ranger, F-150
- Typical Bolt Pattern: 5x4.5 (Mustang), 5x4.25, 5x5.5 (some trucks)
Identifying Features:
Round 10-bolt cover, c-clip axles, available in IRS and solid axle forms.
Generational Differences:
- Pre-1995: 28 spline, drum brakes.
- Post-1995: 31 spline, disc brakes standard in Explorer models.

Ultimate Axle Identification & Spec Guide
Sterling 10.25 / 10.5
Overview: The Sterling axle is Ford's in-house heavy-duty axle found in 3/4 and 1-ton trucks.
Specifications:
- Ring Gear Diameter: 10.25" (early), 10.5" (later)
- Spline Counts: 35
- Bolt Pattern: 12 bolts
- Axle Shaft Diameter: 1.5"
- Weight: ~300 lbs
- Common Applications: Ford F-250, F-350 Super Duty
- Typical Bolt Pattern: 8x170mm (modern Ford), 8x6.5 (older)
Identifying Features:
Flat-back differential cover, full-float only, pinion yoke with large nut.
Generational Differences:
- 10.25 Version (1985-1999): Drum brakes, smaller pinion bearing.
- 10.5 Version (1999+): Disc brakes, larger pinion bearing, stronger housing.

Ultimate Axle Identification & Spec Guide
Gear Ratio Reference & Recommendations
Common Stock Gear Ratios:
- Dana 30: 3.07, 3.55, 4.10
- Dana 44: 3.54, 4.10, 4.56
- Dana 60: 4.10, 4.56, 5.13
- 14 Bolt: 4.10, 4.56
- Sterling: 3.73, 4.10, 4.30
Recommended Gear Ratios by Tire Size:
- 33" Tires: 4.10 - 4.56
- 35" Tires: 4.56 - 4.88
- 37" Tires: 4.88 - 5.13
- 40" Tires: 5.13 - 5.38
Crawl Ratio Formula:
Crawl Ratio = (First Gear Ratio) x (Transfer Case Ratio) x (Axle Ratio)

Ultimate Axle Identification & Spec Guide
Bolt Pattern & Axle Width Reference
Common Bolt Patterns:
- 5x4.5: Jeep TJ/XJ/YJ
- 5x5.5: Early Ford, Dodge
- 6x5.5: GM 1/2-ton, Toyota
- 8x6.5: GM/Dodge/Ford 3/4 and 1-ton (pre-1999 Ford)
- 8x170mm: Ford Super Duty (1999+)
- 8x200mm: Ford DRW (dually)
Common Axle Widths (WMS-WMS):
- Dana 30 (TJ/XJ): ~60"
- Dana 44 (TJ Rubicon): ~61"
- Ford 8.8 (Explorer): ~59.5"
- GM 14 Bolt (SRW): ~67"
- Dana 60 (Ford HP): ~69-74"
- Sterling 10.25/10.5: ~65-67"

Ultimate Axle Identification & Spec Guide
U-Joint Size Comparison
U-Joint Series Specs:
- 1310: Cap Dia 1.062", Cross Width 3.219"
- 1330: Cap Dia 1.062", Cross Width 3.625"
- 1350: Cap Dia 1.188", Cross Width 3.625"
- 1410: Cap Dia 1.188", Cross Width 4.188"
- 1480: Cap Dia 1.375", Cross Width 4.188"
Strength Ranking (Low to High):
1310 < 1330 < 1350 < 1410 < 1480
Tips:
- Use 1350 or 1410 for 1-ton swaps or V8 power
- Greasable joints require more maintenance but last longer while having slightly reduced strength.