47RE Direct Drum: Aluminum vs Billet vs OEM Steel

Replacing your 47RE direct drum? You have three options: OEM steel, HD aluminum, or billet. Heres what each handles and what they cost.

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OEM steel direct drum

Spec:

  • Original equipment
  • ~440 ft-lb stock
  • Steel construction

    • Cost: $200-$350

    Best for:

  • Stock Cummins truck
  • Service replacement
  • Cost-sensitive rebuild

    • Limitations:

  • Same failure pattern as failed drum
  • Wont hold tuned torque

    • HD aluminum direct drum

    Spec:

  • Aluminum alloy
  • ~650 ft-lb rated
  • Lighter than steel

    • Cost: $300-$500

    Best for:

  • Mild tune trucks (under 500 ft-lb)
  • Cost-quality balance
  • Tow with mild tune

    • Limitations:

  • Limited HP capacity
  • Not race-ready

    • Billet steel direct drum

    Spec:

  • 4340 chromoly billet steel
  • 1,200+ ft-lb rated
  • Hardened splines

    • Cost: $700-$1,200

    Best for:

  • Tuned Cummins (600+ ft-lb)
  • Heavy tow + tune
  • Race trucks

    • Limitations:

  • Expensive
  • Overkill for stock truck

    • Comparison table

    OEM steel:

  • Capacity: 440 ft-lb
  • Cost: $200-$350
  • Best use: stock truck

    • HD aluminum:

  • Capacity: 650 ft-lb
  • Cost: $300-$500
  • Best use: mild tune

    • Billet:

  • Capacity: 1,200+ ft-lb
  • Cost: $700-$1,200
  • Best use: tuned/race

    • Which to buy for your truck

    Stock truck under 440 ft-lb:

  • OEM steel
  • $200-$350

    • EFI Live tune + tow (500-600 ft-lb):

  • HD aluminum
  • $300-$500

    • Cammed Cummins + box tune (600+ ft-lb):

  • Billet
  • $700-$1,200

    • Sled pull / race (800+ ft-lb):

  • Billet mandatory
  • Plus billet input shaft

    • Pair with these parts

    For any drum replacement:

  • Direct clutch pack (always)
  • Piston seals
  • Apply piston
  • Sealing rings

    • For HD/billet builds:

  • HD billet input shaft
  • HD OD drum
  • Read our 47RE direct drum upgrade

    • Bottom line

    Match drum to power level:

  • Stock = OEM steel
  • Mild tune = HD aluminum
  • Hard tune = billet

    • Buying too small = repeat rebuild

    Buying too big = wasted money on stock truck

    Need 47RE direct drum (OEM, HD, billet) or HD parts? Shop our 47RE catalog. Direct drums, billet input shafts, HD rebuild kits. Free shipping over $70.

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