The 4L80E pump bushing is the single most common cause of front trans leaks and converter shudder. Replace it during any rebuild or service.
What the pump bushing does
- Supports the torque converter input
- Seals the front pump area
- Carries converter charge pressure
- Direct wear contact with the converter hub
Symptoms of worn pump bushing
Front leak:
- Fluid on bell housing
- Drip at converter inspection cover
- Worsens over time
Converter shudder:
- TCC apply shudder
- Worsens when warm
- Often misdiagnosed as bad converter
Metal in pan:
- Brass particles on magnet = bushing wear
- Confirms pump bushing failing
Why it wears
- Converter hub run-out
- Engine/trans misalignment
- Excessive HP (stock bushing limit ~500 ft-lb)
- Old fluid lacks lubrication
Replacement parts
OEM bushing:
- AC Delco PN 8642186
- $15-$30 part
- Same wear pattern repeats
HD Sonnax bushing:
- PTFE-coated or hardened
- $30-$60 part
- Doubles service life
- Required for HD or HP builds
Also replace:
- Front pump seal
- Pump body O-ring
- Stator support bushing (if worn)
Install
- Trans must come out
- Pull pump assembly
- Press out old bushing with bushing driver
- Press in new with same tool
- Verify pump body is true
- Reassemble with new seal
Cost
DIY:
- HD bushing: $30-$60
- Pump seal: $15-$30
- Gaskets: $40-$70
- Fluid (12 qts Dexron VI): $110-$170
- Tools (bushing driver): $50-$120 if needed
- Total: $245-$450 (one-time tool cost)
Shop:
- Labor: $800-$1,200 (trans R&R + pump teardown)
- Parts: $80-$160
- Fluid: $110-$170
- Total: $990-$1,530
Always replace converter when replacing bushing
A worn pump bushing usually means the converter hub is also worn. Reinstalling the old converter wears the new bushing in 5,000-10,000 miles. Cheaper to replace converter at the same time.
Related work worth doing at same time
- Stator support inspection
- Pump rotor wear check
- Front seal (always)
Need 4L80E pump bushing, converter, or rebuild kit? Shop our 4L80E catalog. HD bushings, HD converters, complete rebuild kits. Free shipping over $70.
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