The 4L60E 2nd gear servo apply pressure is one of the cheapest, biggest gains you can make on a daily driver or HD build. Here is which servo and why.
What the 2nd gear servo does
- Applies the 2-4 band when shifting to 2nd
- Larger apply area = more clamp force on the band
- Less slip = less heat = longer band life
- Crisper 1-2 shift
Servo apply area comparison
Stock 4L60E servo:
- ~3.3 sq in apply area
- OEM for most light-duty applications
- Slip-prone under load
Corvette servo (PN 24202707):
- ~3.7 sq in apply area
- ~12% more clamp force
- OEM upgrade from C5/C6 Corvette
- $25-$50 part
Sonnax super-hold servo:
- ~4.0 sq in apply area
- ~20% more clamp force
- $50-$90 part
- Best for tow/HD/performance
Symptoms that say servo upgrade is overdue
- 2-3 flare under load
- Burnt 2-4 band when rebuilding
- Soft 1-2 shift
- Slip on grade with trailer
Install difficulty
In-vehicle (without trans removal):
- Drop pan and exhaust
- Remove servo cover (4 bolts)
- Pull old servo, install new
- 2-3 hours DIY
Easy upgrade during rebuild:
- Trans is out anyway
- Add 10 min of labor
- Stupid to skip when rebuilding
Pair with shift kit for biggest gain
- Servo gives more apply force
- Shift kit gives faster apply
- Combined: night-and-day shift quality
- Read our 4L60E shift kit guide
Cost
DIY upgrade:
- Corvette servo: $25-$50
- Sonnax super-hold: $50-$90
- Fluid + gasket: $30-$50
- Total: $55-$140
Shop upgrade:
- Parts: $55-$140
- Labor: $150-$300
- Total: $205-$440
Related upgrades worth bundling
- 2-4 band (Raybestos red or Kevlar)
- Shift kit (TransGo HD2 or Sonnax)
- 3-4 clutch pack upgrade
Need 4L60E servo, 2-4 band, or full rebuild kit? Shop our 4L60E catalog. Corvette servos, Sonnax super-hold, complete rebuild kits. Free shipping over $70.
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