DIFFERENTIAL & DRIVETRAIN — 1989–1993 DODGE RAM 5.9L CUMMINS (12-VALVE)

Build a stronger, smoother first-gen drivetrain with CPP Diesel. This category focuses on ring & pinion gears, master install kits, lockers/LSD, axle shafts, U-joints & yokes, driveshafts, and differential covers tailored to typical 1989–1993 Dodge Ram D250/D350 Dana 60 front and Dana 70/70HD rear applications. Verify your axle tags/BOM and gear ratio (common: 3.54, 4.10) before ordering for perfect fitment.

Shop by Subcategory

• RING & PINION GEARS — broad coverage for Dana 60/70 platforms.
• MASTER INSTALL KITS — bearings, shims, seals, and small parts.
• LOCKERS & LIMITED-SLIP — traction solutions from Yukon.
• AXLE SHAFTS — chromoly & OE replacements.
• U-JOINTS & YOKES — Spicer service parts in common 1310/1410/1480 series.
• DRIVESHAFTS — direct-fit front shaft for ’90–’93 W-series plus many others.
• DIFFERENTIAL COVERS — Mag-Hytec cooling-fin covers for Dana axles.
• FLUIDS & ADDITIVES — complete fluid change kits and accessories.
• AXLE ASSEMBLIES — reman front diff assemblies for select 1st gens.

Featured for 1st Gen

• MAG-HYTEC 60-DF Dana 60 Front Cover — added capacity + cooling.
• Dana Spicer 1485-WJ U-Joint — heavy-duty driveline service.
• Yukon Lockers & Axles — strength for towing and big-tire builds.

Why Buy from CPP Diesel

• First-Gen Focus: Curated for 1989–1993 VE-pump 12-valve platforms.
• Top Brands: Yukon Gear & Axle, USA Standard Gear, Dana Spicer, Mag-Hytec, Zumbrota.
• Expert Support: Gear ratio selection, contact pattern tips, and torque specs.
• Fast Shipping: Popular U-joints, covers, and hardware ship quickly.

See the full 1989–1993 Cummins catalog for complementary upgrades.

Helpful Notes

• Typical axles: Dana 60 front / Dana 70 rear on most 1st gens; confirm BOM tags and spline counts.
• Ratios: 3.54 and 4.10 are common; match to tire size & use case.
• Setup matters: Always use a master kit when re-gearing; verify backlash, preload, and pattern.
• After lifts: Re-check pinion angle and U-joint phasing to cure vibrations.

Frequently Asked Questions

What gear ratio works best with 33–35" tires?

Most 1st gen owners choose 3.73–4.10 to restore drivability and towing power. Pick based on highway RPM targets and terrain.

Locker or limited-slip for a street-driven tow rig?

Limited-slip offers smoother manners in rain/snow and while towing. Lockers provide maximum traction but can be more abrupt in tight turns.

Do I really need a master install kit when changing gears?

Yes — new bearings, shims, seals, and hardware help set correct preload/backlash for long gear life.

How do I break in new ring & pinion gears?

Perform several short heat cycles with cool-downs. Avoid heavy loads and WOT during initial break-in, then change fluid as recommended.

Which U-joint series do I need?

Many 1st gens use 1310/1410 series joints; heavier builds may step to 1480. Compare cap diameter and span to your yokes before ordering.