4L60E Information Thread (Includes 4L65E/4L70E)

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NickTransmissions

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Hey Everyone,

Starting a similar thread to the 6L80 post but dedicated to the 4L60E as countless GM cars, trucks and SUVs were fitted w/them from 1993-2013/14, including those owned by many of us (I have a 2003 Tahoe Z71). Posted below is my teardown and inspection video that covers everything you need to check for as well as a link to my 4L60E playlist that covers valve body disassembly and reassembly, full rebuild, and related topical videos. I included a complete parts and machining procedures list as well so folks have a comprehensive view of everything that needs to go into these transmissions for a proper overhaul. Lastly, I have included some tech resources and information for those that want to rebuild their own 4L60/65/70E transmission. Most of the 4L60E parts (apart from valve body, pump and electrical components) also apply to the 700R4, for those that have an older vehicle so equipped.

I'll edit to add and update content as I go; will bump the thread if a whole bunch of updates are made.

4L60E Teardown and Inspection

4L60E Build for High Performance

4L60E Playlist

Tech Resources
GM Technician's Guide (mostly diagrams)
4L60E Limp Mode Diagnostics
DTC P1870 TSB
TSB for Harsh 3-2 downshift (note: this condition is normal in the 4L60E and 700R4)

Parts and Machining Services for Overhaul
4L60E PartsGM Part Number (If applicable)Notes
Paper and rubber kitThis kit is also referred to as an 'overhaul kit'
Clutch moduleRaybestos or Borg Warner - factory level module comes with high energy 3-4 frictions
3-4 clutch steel moduleKolene steels recommended but not required
Borg Warner high energy 2-4 bandAlto wide band is a good upgrade - reverse input drum must be new or resurfaced
Corvette 2nd gear servo (093)Good upgrade for all GM medium duty cars, trucks and SUVs
Complete bushing kit
Sonnax wide rear sun gear bushingRecommended for all rebuilds as the factory rear sun gear bushing likes to walk out on higher mileage units; mandatory for high performance
Hardened and heat treated sun gear reaction shell
Forward thrust bearing
3-4 clutch apply plate and backing plateNot mandatory but often required due to severe 3-4 clutch burn up
Borg Warner input sprag clutch (29 element)Use 400 grit sand paper to reintroduce cross-hatching on outer race-sprag surface
Aluminum 3-4 accumulator pistonAll years take a large hole piston
Aluminum 1-2 accumulator pistonSome very early 4L60Es have a large hole piston; most have small hole
Borg Warner low roller one way clutch assemblyThis one-way clutch is only holding in first gear thus doesn't fail often
All solenoids (EPC, shift solenoids A&B, 3-2 control solenoid (93-08), pressure switch manifold assembly (93-08), wiring harnessUse OEM or Rostra only!
Manual lever position sensor: Dual connector: 1996-2003 | single connector: 2004-2008GM/AC Delco or Rostra

Good time to replace this as if it fails, you won't be able to start your vehicle
Internal mode switch (2009+)GM/AC Delco only!

Good time to replace this as if it fails, you won't be able to start your vehicle
Turbine (input) speed sensor (L2006+)GM/AC Delco only!; consult dealership parts dept to confirm if yours has a turbine speed sensor

Must replace this on all overhauls when equipped - you cannot replace this sensor when the trans in the vehicle!
Sonnax LB4L60E boost valve kitInstall in place of worn out factory boost valve and sleeve
Machining Services
Pump body and cover resurfacing and milling (pump body only)Provide machinist your pump rotor and slide - these are selective and clearance must be as follows:
- Rotor to pump body deck: .0015-.0025
- Slide to pump body deck: .002-.003
Reverse Input DrumCheck for warped surface (most are warped when they come in) - resurface to restore to as-new condition
Fitzall separator plate repair kitWill service multiple separator plates (1-2 check ball usually wears and needs a repair sleeve from the kit)
Sonnax TCC Regulator valve kit (oversized)Requires tool, base and support fixture to hold valve body as well as Sonnax bore reamer kit

Use either Fitzall drop in valve for applicable year range (95-2000, 2001-2006); this valve converts the TCC apply strategy to an on-off from a PWM (pulse width modulation)

Cannot be done for any vehicles with VVT or active cylinder management as the PWM must be working properly
Sonnax oversized actuator feed limit (AFL) valve kitRequires tool, base and support fixture to hold valve body as well as Sonnax bore reamer kit

Worn AFL valves / valve bores will cause a myrid of symptoms and failures thus all valve bodies must be tested
Corrective & Performance Upgrade Options (list not exhaustive)
Shift Kit (basic)Transgo SK4L60E | Superior Technologies 4L60E
Shift Kit (performance)Transgo HD2 | Sonnax Surecure Kit (preferred)
Transgo unbreakable pump rings (5500 RPM+)
Transgo high rate forward drum return spring kit
GM OEM five pinion front and rear planetary carrier assembliescan be good used or rebuilt by a competent machinist
Sonnax Smart ShellBest sun gear reaction shell on the market
4L65E Input drum assemblyInduction hardened input shaft
4L65E 3-4 clutch pack kit (7 frictions and six steels, apply plate and HD backing plate)High energy clutch material
4L70E Reaction shaftInduction hardened splines
Sonnax Smart Tech Input DrumExpensive but as close to bulletproof as you can get for these transmissions
Sonnax input drum reinforcement kitReinforces factory input drum for high RPM and power levels below 550 HP
Raybestos Blue Plate friction moduleFull race only
Alto High Energy or Raybestos ZPG or Stage One friction moduleGreat all around street/strip
Sonnax Super hold servo assemblies (2nd and/or 4th gear)A must for heavy towing and/or hauling as well as street/strip - race
CK Performance Billet pump rotorGreat for racing and other 5500+ RPM uses
 
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Mudsport96

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Good list there.
In all honesty ive only ever used the HD2 kit with the Oregon performance billet servos and beast sunshell. Never hurt any clutches in a 60e.... broken plenty of hard parts though. Stator in the converter, output shaft (4x4 shafts apparently break easier than 2wd) stock sunshells, and oddly enough a flexplate.
 
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NickTransmissions

NickTransmissions

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Good list there.
In all honesty ive only ever used the HD2 kit with the Oregon performance billet servos and beast sunshell. Never hurt any clutches in a 60e.... broken plenty of hard parts though. Stator in the converter, output shaft (4x4 shafts apparently break easier than 2wd) stock sunshells, and oddly enough a flexplate.
Yep, the only vulnerable clutch is the 3-4 and only if its not set up right. I actually dont use the HD2 kit either; everything that kit does can be accomplished without it for much cheaper.

Ive seen many stock flexplates go under high power and recommend SFI flexplates for anything hp, racing, super heavy duty.

Ill be adding a few 4L60e performance videos to the OP a littlelater today, including a vid on valve body mods and spacer plate hole sizing.
 

Mudsport96

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Ill be adding a few 4L60e performance videos to the OP a littlelater today, including a vid on valve body mods and spacer plate hole sizing.
On the pre-torque management stuff i tried to be pretty precise with hole sizes. But after what 99-00 i would go a tick oversized and let the computer nanny it out and never had much issue.
 

89Suburban

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Bump - Added the first of a five-part series on building 4L60Es for high performance applications. Feel free to post anything else that can potentially be incorporated into a high performance build up.

Thanks so much for taking the time to do this and share it here.
 

89Suburban

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The converter clutch is applied/on upon start up? Is the vehicle stalling out when put into gear (fwd or reverse) as if you let your foot off the clutch while in gear with a manual transmission?
On some random cold starts over the years I get this driveline slam and the truck jumps. Could be something else causing it I guess. I don't know how else to exsplain it.
 

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