47RE / 48RE Pan Drop & Magnet Inspection Guide

The 47RE/48RE pan service is the cheapest diagnostic in your Cummins truck. Heres how to drop the pan, inspect the magnet, and understand what the debris is telling you.

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Why pan inspection matters

Free trans health check:

  • Catches issues 20-50k miles before failure
  • Identifies specific failing components
  • Costs nothing if doing fluid service anyway

    • What you need

    Tools:

  • 10mm socket
  • Inch-pound torque wrench
  • Drain pan (15+ qt)
  • Shop towels
  • Cardboard

    • Parts (if servicing):

  • ATF+4 (13 quarts): $100-$160
  • Pan gasket: $10-$25
  • Filter: $15-$30
  • Total: $125-$215

    • Step-by-step

    Step 1: Warm trans

  • Drive 10 minutes
  • Operating temp

    • Step 2: Raise truck

  • Jack stands
  • Drain pan positioned

    • Step 3: Drain

  • Plug if equipped
  • Or loosen pan corners
  • Catch 7+ quarts

    • Step 4: Drop pan

  • 14 bolts
  • 10mm
  • Pan may stick

    • Step 5: Inspect magnet

  • Photograph for records
  • Note debris type

    • Step 6: Replace filter

    Step 7: New gasket and reinstall

    Step 8: Refill and check level

    What the magnet tells you

    Fine gray dust (normal):

  • Light dusting
  • Service interval OK

    • Brass particles:

  • Pump bushing wear
  • Plan pump rebuild within 50k miles
  • Cost to fix: $800-$1,500

    • Steel pieces:

  • OD drum cracking
  • Direct drum failure
  • Stop driving
  • Cost to fix: $4,000-$7,000

    • Aluminum flake:

  • Case wear (rare)
  • Or aluminum part disintegrating
  • Major investigation needed

    • Burnt friction (brown/black flakes):

  • Doesnt stick to magnet
  • Direct or OD clutch wear
  • Plan rebuild within 30k miles

    • 47RE/48RE specific failure patterns

    Brass on magnet:

  • Pump bushing first
  • Common at 150k+ miles

    • Steel chunks:

  • OD drum failure (#1 catastrophic)
  • Tuned trucks especially

    • Steel + brass + burnt friction:

  • Multiple system damage
  • Major rebuild needed

    • By mileage baseline

    Under 50k miles:

  • Magnet nearly clean
  • Any debris is concerning

    • 50-100k miles:

  • Light gray dust
  • Healthy if no shavings

    • 100-150k miles:

  • Moderate gray dust
  • Brass concerning

    • 150-200k miles:

  • Heavier dust
  • Brass indicates wear progressing

    • 200k+ miles:

  • Significant debris
  • Plan rebuild within 50k miles

    • Tuned Cummins specific

    Common debris pattern:

  • Steel from OD drum
  • Brass from pump bushing
  • Burnt friction from direct clutches
  • All within 80k-150k miles tuned

    • Prevention:

  • HD billet input shaft
  • HD billet OD drum
  • HD direct clutches
  • HD torque converter
  • Done together = 200k+ life

    • Photo journal habit

    Why:

  • Compare each service
  • Track gradual changes
  • Catches issues early

    • How:

  • Photo at every fluid change
  • Same lighting and angle
  • Save with mileage/date

    • Filter inspection (additional clue)

    Cut open old filter:

  • Look at media inside
  • Sometimes reveals more than pan
  • Particle trapped in filter shows path of debris

    • Common findings:

  • Clutch material in filter media
  • Metal particles trapped
  • Sludge from old fluid

    • Common DIY mistakes

    Skipping magnet inspection:

  • Free diagnostic missed
  • Catches issues early

    • Not cleaning magnet:

  • Old debris obscures new findings
  • Clean every service

    • Confusing burnt friction for metal:

  • Friction is brown/black flaky
  • Doesnt stick to magnet
  • Metal sticks to magnet

    • Over-tightening pan bolts:

  • 100 in-lb (not ft-lb)
  • Cross pattern
  • Over-tight warps pan

    • What to do with findings

    Light dust only:

  • Continue normal service interval
  • 30k miles tow / 60k daily

    • Brass particles:

  • Plan pump service ($800-$1,500)
  • Or service more frequently
  • Inspect again in 10k miles

    • Steel pieces:

  • Major repair needed
  • $4,000-$7,000 typical
  • Get rebuild quote

    • Burnt friction:

  • Plan rebuild
  • Service service buys time

    • Pair pan service with TV cable adjustment

    • Best time to check TV cable
    • Free preventive maintenance
    • Often improves shift quality
    • Read our 47RE TV cable guide

    Pair with governor solenoid inspection

    Time and cost

    DIY service + inspection:

  • 2-3 hours
  • $125-$215 parts
  • Free diagnostic value

    • Shop service:

  • $250-$450
  • Often skips magnet inspection
  • Or doesnt photograph for you

    • Annual fluid color check

    Free monthly visual:

  • Pull dipstick at oil change
  • Verify red color
  • Note any changes

    • Color trend over time:

  • Bright red: healthy
  • Light brown: service due
  • Dark brown: overdue
  • Burnt: damage

    • Bottom line

    Pan inspection at every service:

  • Free diagnostic
  • Catches issues 20-50k miles early
  • Saves thousands in surprise repairs

    • Tuned trucks: inspect more often

    Stock trucks: 30k mile intervals adequate

    Need 47RE/48RE service parts (fluid, filter, gaskets) or rebuild parts? Shop our 47RE/48RE catalog. ATF+4, filters, gaskets, master rebuild kits. Free shipping over $70.

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