The 4L60E 3-4 clutch pack is the #1 wear item in the trans. Slips at 80k-150k miles even on stock trucks. Upgrading to Raybestos GPZ is the highest-ROI rebuild move you can make.
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Doing the whole job? 4L60E Master Rebuild Kit - Frictions & Steels, Gaskets & Seals, Filter, Shift Kit, Servo, Solenoids, Bushings (7-Piece) — $233.99 $245.99 (save 5% vs buying separately)
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What the 3-4 clutch pack does
- Engages in 3rd AND 4th gears
- Most-used clutch (active in 50%+ of driving)
- Smallest clutch pack by capacity
- Sized barely above stock torque
Symptoms of failure
- 3-4 shift flare (engine revs between gears)
- Slip in 3rd or 4th under load
- Burnt fluid smell
- Black flake on pan magnet
- Sometimes complete loss of 3rd and 4th
- Truck stuck in 2nd (limp mode equivalent)
Why this pack wears out first
Smallest pack in the trans:
- Stock: 3 friction discs + 3 steels
- Other packs have 5-6
- Limited surface area = limited capacity
Most usage:
- Engaged in 3rd and 4th gears
- Lockup TCC adds heat to this pack
- Cruise = constant load
Heat buildup:
- Small pack heats fast
- Cooks the frictions
- Glazing reduces grip
GPZ upgrade pack
What GPZ is:
- Graphitic friction material
- Higher heat tolerance
- Higher coefficient of friction
- Same dimensions as OEM (drop-in)
Capacity gain:
- Stock: ~350 ft-lb at the trans
- GPZ: ~500 ft-lb at the trans
- ~40% capacity increase
Cost:
- $50-$100 part (just frictions)
- $80-$160 (frictions + steels kit)
- Cheapest HD upgrade in the trans
Even better: Sonnax HD pack
- 4-disc pack (adds 1 friction)
- Requires deeper drum (Sonnax kit)
- $200-$400 set
- Required for 500+ ft-lb builds
Always replace at rebuild
- If trans is open, do the GPZ upgrade
- $50 extra material for huge longevity gain
- Skipping is leaving money on the table
Install
- Trans must come out (or use in-vehicle access)
- Drop pan, valve body, then accumulator housing
- 3-4 piston housing comes out
- Old clutches lift out
- Install new frictions soaked in fluid
- Install new steels (replace if blue or warped)
- Reassemble in reverse
Cost
DIY GPZ upgrade only:
- GPZ pack: $80-$160
- Gasket + seal kit: $30-$60
- Fluid: $40-$80
- Total: $150-$300
Shop install:
- Parts: $150-$300
- Labor: $400-$700 (in-vehicle) / $1,000-$1,800 (full rebuild)
- Total: $550-$2,100
Pair with shift kit
- Faster 3-4 apply = less slip-time = less heat
- TransGo HD2 or Sonnax shift kit
- $80-$200 part
- Reduces 3-4 wear another 30%
- Read our 4L60E shift kit guide
When 3-4 pack is not enough
- 3-4 clutch drum cracked (rare)
- 3-4 piston seal failed (always replace at rebuild)
- Apply pressure low (stator support issue)
Need 4L60E 3-4 clutch pack, GPZ frictions, or full rebuild kit? Shop our 4L60E catalog. Raybestos GPZ packs, Sonnax HD sets, complete rebuild kits. Free shipping over $70.
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