4L80E Pump Body Replacement: Cracked Case, Worn Pump Fix

The 4L80E pump body is the front-most casting on the trans, machined to thousandths-of-an-inch tolerance. When it cracks or wears beyond spec, full replacement is the only fix.

Related 4L80E guides

Shop the parts for this fix

Doing the whole job? 4L80E Master Rebuild Kit - Frictions & Steels, Gaskets & Seals, Filter, Shift Kit, Servo, Solenoids (6-Piece) — $246.99 $259.99 (save 5% vs buying separately)

Or grab the individual parts:

4L80E Front Pump Gasket 1991-2013 OEM 8677782
The part for this fix
4L80E Front Pump Gasket 1991-2013 OEM 8677782
$12.99 · In stock
Shop This Part →

What the pump body does

  • Houses the pump rotor and slide
  • Provides pressure regulator bore
  • Reaction surface for converter charge
  • Mounts to front of trans case (13 bolts)
  • Houses converter front seal

Symptoms of pump body failure

Cracked body:

  • Front leak that wont stop with new seal
  • Pressure drop (especially WOT)
  • Visible crack on inspection

    • Worn pressure regulator bore:

  • Erratic line pressure
  • Soft or harsh shifts (depending on wear)
  • P0747/P0748 codes possible

    • Worn boost valve bore:

  • Low pressure under load
  • Slip at WOT
  • Soft TCC apply

    • Worn pump body face:

  • Pump rotor wears unevenly
  • Whine from pump
  • Repeat pump failures even with new rotor

    • Replacement parts

    OEM pump body (rebuilt):

  • $300-$500 part
  • Same wear pattern in 100k miles

    • OEM pump body (new):

  • $600-$900 part
  • Limited availability

    • HD aftermarket (Sonnax billet):

  • $500-$900 part
  • Hardened wear surfaces
  • Required for HD use

    • Sonnax bore repair (not replacement):

  • $80-$200 kit per bore
  • Sleeve installation in worn bores
  • Cheaper than full body replacement
  • Skill level: advanced DIY

    • Always replace together

    • Pump rotor + slide
    • Pump body bushing
    • Front seal
    • Pump body O-ring
    • All sealing rings on input shaft
    • Read our 4L80E pump bushing

    Install

    • Trans must come out
    • Pull pump assembly from trans (13 bolts to case)
    • Separate pump body from stator support
    • Inspect both halves
    • Replace bushings (press tool required)
    • Reassemble pump with new internals
    • Verify rotation freedom before mounting
    • Install on trans with new gasket and O-ring
    • Torque 13 bolts in cross pattern (18 ft-lb)

    Cost

    DIY pump body replacement:

  • Pump body (rebuilt): $300-$500
  • Pump rotor + slide: $120-$220
  • Bushings: $80-$140
  • Front seal: $20-$40
  • O-rings + gaskets: $40-$80
  • Fluid: $110-$170
  • Total: $670-$1,150

    • DIY HD pump body:

  • HD body: $500-$900
  • HD rotor + slide: $180-$280
  • HD bushings: $80-$140
  • Seals + gaskets: $60-$100
  • Fluid: $110-$170
  • Total: $930-$1,590

    • Shop install (during rebuild):

  • Parts: $670-$1,590
  • Labor: $1,500-$2,500
  • Total: $2,170-$4,090

    • Pair with stator support

    What kills 4L80E pump bodies fastest

    • Old burnt fluid (varnish in bores)
    • Tuned engine + stock pump (excessive pressure demands)
    • Hard launches with stiff converter
    • Skipping filter changes
    • Wrong fluid (always Dexron VI)

    Common buyer mistakes

    • Replacing rotor only, leaving worn body (repeat failure)
    • Reusing front seal (always replace)
    • Not replacing pump body bushing
    • Skipping pressure test after install

    Need 4L80E pump body, rotor kit, or rebuild parts? Shop our 4L80E catalog. Pump bodies, HD upgrades, complete rebuild kits. Free shipping over $70.

    Related: