4L60E Information Thread

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

NickTransmissions

Supporting Member
Supporting Member
Joined
Aug 16, 2023
Messages
673
Reaction score
1,081
Location
Las Vegas
Hi All,

Since so many of us own at least one GMT400 or similar truck/SUV equipped with a 4L60E, I figured I'd start an all-encompassing transmission thread with videos, links and other information as it relates to the 4L60/65/70/75E transmissions. I'll get it going with videos covering tear down and inspection, step by step rebuild procedures as well as high performance and go from there.

Hoping this can be an easy 'one-stop shop' for exchanging information, guidance and advice as it relates to 4L60E transmissions.

I'll update this first post with more over time and bump the thread when new stuff gets incorporated.

Feel free to post questions, comments, etc...

Note - Feel free to send me a PM w/any questions but please provide your first name (unless it’s in your user name) so that I know who I'm talking to - TIA.

4L60E Production Run: 1992-2013

4L60E Teardown and Inspection

xc_hide_links_from_guests_guests_error_hide_media


4L60E Rebuild Series (Stock level build)
xc_hide_links_from_guests_guests_error_hide_media


4L60E Rebuild Series (High Performance)
xc_hide_links_from_guests_guests_error_hide_media


4L60E Valve Body Tips and Tricks
xc_hide_links_from_guests_guests_error_hide_media


Vintages and Interchange Information
The following information applies to all 4L60E-equipped models and sub-models unless otherwise noted.

VintageComponentsInterchange InformationAdditional Context
1992-1994
  • Valve Body
  • Pump Assembly
  • Separator Plate
  • Wiring harness
  • 3-2 Solenoid
1992-1994 units will interchange as an assembly into any vehicles manufactured during these years

1995 and 1996-1997: Components at left will have to be swapped for compatible components for those years/vintages if needing to convert to a 95 or 96-97 application
  • Separator plates not provisioned for PWM TCC apply strategies
  • 3-2 Solenoid Resistance: 9-11 ohms
  • Replacement part: 96+ PWM solenoid

Valve body castings have provision for PWM solenoid however no PWM solenoid is installed for 1992-1994
1995
  • Valve Body
  • Pump Assembly
  • Separator Plate
  • Wiring harness
  • 3-2 Solenoid
Not interchangeable with any other year without swapping the following parts w/year-applicable ones:
  • Pump
  • Valve body
  • Separator Plate
  • Wiring Harness
  • PWM Solenoid
*** 1992-1995 Cases will not swap to 1996+ vehicles as they lack provisions for mounting the MLPS - see next row for details
Pulse Width Modulation was introduced as a new TCC apply strategy for all 4L60E transmissions starting in 1995. In 1996, key changes to the PWM were made and further changes were made in 2001+ and in both cases, updates were made to the valve body, separator plate and separator plate gaskets.
1996-1997
  • Case
  • Valve Body
  • Separator Plate
  • Wiring Harness
  • 3-2 Solenoid
  • Manual lever position sensor
Will not interchange with any prior years without swapping components listed at left with counterparts that are compatible with the target vintage (i.e. 92-94 or 95)

May swap in place of a two-piece case so long as the engine is a 1st or 2nd generation small block or big block - WILL NOT swap in behind a Generation 3 small block (LS1, 5.3, 6.0, etc)
In 1996, GM introduced the manual lever position sensor and changed the impedance of the 3-2 control solenoid to 18-21 ohms, which mirrors that of shift solenoids A and B

PWM Solenoid remained unchanged (9-11 ohms)

Threaded ports were added on either side of the selector to accommodate the manual lever position sensor - these threaded ports ARE NOT found on 1992-1995 cases

** It’s recommended to mechanically convert the PWM regulated apply circuit in the valve body to an ‘on-off’ circuit - this is accomplished by blocking the inboard valve from moving **

DTC P1870 will store if/when this valve wears sufficiently and late, harsh 1-2 shifts will often be observed
1993-2000Separator plate gasketsInterchangeable between all years at left

Identified by the lack of striping on both gaskets
PWM-specific ports and orifices on the separator plate changed starting in 2001 to coincide with some other minor PWM-related hardware changes (see below for details)
1996-2003Manual Lever Position Sensor (first design)Will interchange between all years at leftFirst design uses two connectors to communicate range position - one for Park and one for Neutral.

Use a heat gun or hair dryer to melt the dielectric grease so that the MLPS can be removed from the pig-tail connectors w/out damaging the connectors or sensor

If this sensors fails, vehicle will not crank or start - try shifting into Neutral if in Park - it may start if only the ‘Park’ channel has failed
2004-L2008Manual Lever Position Sensor (second design)Will interchange between all years at left but WILL NOT interchange with vehicles manufactured for model years 1992-2003Second design uses one electrical connector instead of two, integrating Park and Neutral into one channel for data comms w/the PCM
2001-2006Separator plate gasketsInterchangeable between all years at left

Identified by white striping on both gaskets
GM updated the separator plate with new ports/orifice designs starting in 2001 - this coincided with a redesigned valve train in the TCC regulator valve (valve body)
1998-2006
  • Case
  • Bell Housing
  • Torque Converter
  • Input Shaft
Interchangeable across all years with the caveat that F-body or Corvette specific parts will need to be installed on transmissions that did not already have them if installing into an F Body (Camaro or Firebird) or a Corvette300mm pump stator and redesigned input shaft introduced in 1998 to support migration to LS/Gen 3 small block in Corvettes and F-bodies

All other 4L60E equipped vehicles followed suit in late 2000
2006-2008
  • Pump Assy
  • Input Shaft
  • Input Speed sensor
  • Valve Body
  • Separator plate
  • Separator plate gaskets
  • Wiring Harness
WILL NOT retro or prospectively install into any other model year vehicles

First years of separator plates w/bonded gaskets

Some units will have a traditional separator plate where gaskets can be replaced separately

Use orange-striped separator plate gaskets
GM introduced the turbine shaft speed sensor in mid-2006 which resulted in design changes to the input shaft, pump stator and pump cover.

** Failure to install a pump with a matching input shaft or pump not compatible with a turbine speed sensor into a 4L60E-equipped vehicle that originally came w/one will result in no upshift from first gear

CAUTION! - A limited amount of input shaft/drum assemblies were manufactured as provisioned for the reluctor gear however no gear was cast into these shafts and mated to pumps with stators provisioned for the input shaft reluctor gear - DO NOT install these into transmissions that originally did not come w/turbine speed sensors as the feed holes between the stator and input shaft will be mis-aligned (mostly applies to L2006)
L2008+
  • Valve body
  • Separator plate
  • Pressure Switch Manifold Assembly
  • Internal Mode Switch
  • Wiring Harness
  • Manual Lever Position Sensor
Will interchange with any subsequent year however not backwards-compatible with 2008-1992

*** 2008 4L60/65/70E transmissions not updated to take the internal mode switch (e.g. still have the older pressure switch manifold assembly and external MLPS installed) are compatible with any year vehicle L2006-2008 regardless if that vehicle’s original transmission came with a turbine speed sensor
In 2009, GM introduced the Internal Mode Switch to take the place of the pressure switch manifold assembly and manual lever position sensor.

The IMS is installed onto the selector shaft between the case wall and rooster comb - pan must be removed to access and R/R the IMS.

If IMS fails, vehicle will not crank or start


A Few Common Problems, Causes and Solutions (I will add to this list as I go)

Problem/SymptomCauseFixNotes
No movement in any range (forward or reverse)Pump failure

Input shaft splines stripped

Converter failure

Low roller and sun shell failure

Burnt forwards+coast clutch+low reverse/reverse input
Replace whichever parts at left failedCheck dipstick level off then start engine - if dipstick level is way above full w/engine running pump has failed

If not, put pressure gauge on trans - if pressure is normal, tear down and inspect transmission to PID cause.
No Reverse, 2nd or 4th gearSun shell failure

Rear gear train failure
Replace sun shell and/or gear train on overhaul

Always use hardened / heat treated sun shell at minimum (Sonnax Smart Shell recommended if budget allows for it)
Gear train failure can first present as vehicle ‘locking up’ in reverse or first gear as pieces of gear teeth are preventing mesh of gear components

Momentary neutral conditions at highway speeds also indicate progressive gear train failure
No Reverse; all forward gears workLip seals on reverse input piston and/or low reverse piston wornReplace lip seals on overhaulCommon when trans overheats multiple times or not driven for long periods of time (also affects other seal surfaces)
No forward movement in Drive but forward movement in Manual 2 and 1; reverse worksInput sprag failed

Input sprag installed backwards (overhaul only)
Replace input sprag gear assembly

Correct sprag orientation
Sprag clutch, inner and outer race must all be replaced in the event of sprag failure

Use 400 grit sandpaper on inner dia of replacement outer race to prep surface before installing new sprag clutch
No upshift from 1st gear at all (1992-E2006)Failed output speed sensor or speed sensor harness short-to-groundConfirm it’s plugged in

Replace speed sensor

Fix/replace ext harness
Check harness and related wiring for shorts or damaged wires and verify pigtail is receiving voltage
No upshift from 1st gear at all (L2006)Failed input speed sensor,
output speed sensor
or internal harness short-to-ground or external short to ground
Confirm it’s plugged in

Replace speed sensor

Fix/replace harness
Transmission must be removed from vehicle, pump extracted to replace input speed sensor (aka Turbine speed sensor)
No upshift from 1st gear - eventually shifts to third2nd gear Servo piston/sealing rings

Worn/burnt 2-4 band
Replace rings or Servo assembly w/093 servoAir check 2nd gear apply to confirm / deny the servo is the problem
No forward movement in any range setting - reverse worksFailed low roller clutchReplace roller clutch assemblyCheck center support for cam or lug damage - replace if necessary
Tie Up at 1-2 shift#1 Check ball stuck in plateRepair plate using Fitzall repair sleeve and install torlon check ballCommon for all years, sub-models
Late Harsh 1-2 shift AND P1870TCC reg valve
Torque Converter
Worn rear pump stator bushing
Fix the causes listed at right starting w/TCC reg valve - use Fitzall valve ($20) for 96-2000 vehiclesIf fixing the TCC reg valve w/ a Fitzall valve or Sonnax oversized valve fails to resolve P1870, cause is either TC or pump stator bushings
Late Harsh 1-2 shift BUT NO P1870 DTC stored1-2 accumulator springs brokenReplace broken springs, piston and sealTransgo springs are known to break - I see many 4L60Es come in w/broken springs from Transgo shift kits
No forward movement in Drive but forward movement in Manual 2 and 1Input spragReplace input sprag gear assemblySprag clutch, inner and outer race must all be replaced in the event of sprag failure

Use 400 grit sandpaper on inner dia of replacement outer race to prep surface before installing new sprag clutch
Slipping / neutral during 2-3 shift3-4 pack wiped and burnt
Set clearance to .030-.050

Delete load release springs
Air check forward drum when assembled to confirm/deny 3-4 apply leakage at shaft/drum junction

Replace shaft/drum assy if so and test replacement

See my video for procedure
Third gear start (happens after trans has previously worked properly)Trans in limp modeDiagnose and fix causes which can be
  • Internal Harness
  • Ext Harness
  • Solenoids
  • Pressure Switch Man / IMS
Limp mode - third and reverse only (no other gears accessible)
Third gear starts after rebuildInput drum stator base O-ring (Green) left out or cutGreen o-ring segregates forward and 3-4 apply circuitsInstall new o-ring from a paper/rubber kit
No upshift to fourth gear (previously worked; all other gears available)4th apply piston sealing ring

Worn 2-4 band

3-4 shift valve stuck
Check 2-4 band apply to validate function

Check 3-4 shift valve
Tear down trans - replace band upon overhaul
No upshift to fourth gear after rebuild4-3 relay valve installed backwardsPut valve in the right wayApplies to the 700R4 as well


Parts Selection - Updating (Stock to mild builds)

PartLocationRationale
Accumulator pistonsValve body/Case/1-2 Acc HsngAlways replace old acc pistons with new as they wear at the pin bore and cause leaks in their respective circuits
Torlon Check ballsCase / Valve BodyUse torlon check balls and a larger 5/16” check ball at the 1-2 location to mitigate wear and risk the check ball gets stuck in the plate
Sonnax 4L60E-LB1Pump (Boost valve)Preexisting boost valves are worn; Sonnax boost valve and spring kit provides 10% increase in linear line pressure
Corvette Servo (093)ServoHas 13% more apply surface than ‘553’ servos installed in most v8 non-vette/non-f-body/non-premium sub model truck/SUV applications
97+ Bonded steel / rubber pistons + fwd return spring assyForward DrumRetro these and the corresponding late model forward return spring assembly to all 700R4 and 92-96 4L60Es for more longevity
Wide 2-4 band (Alto)Case - Rev Input DrumFactory-width bands cover appx 80% of drum surface which leads to more rapid warping; wide band covers 97% of surface, leading to better lifespan
4L65E or equivalent 3-4 clutch pack+apply/backing plateForward DrumProvides 7 frictions and steels in the 3-4 clutch pack; Alto, Borg Warner and Raybestos also make equivalent kits
Pump kitPumpComes with new rotor/slide/vanes, rings, small parts
Bushing KitvariousR/R all bushings in the unit
Sun ShellCaseObtain a hardened and heat treated version
Forward Sprag / Low Roller ClutchInput Sprag Assy / Center SupportReplace with new Borg Warner counterparts
Electrical componentsValve body-Pan areaAlways replace all electrical components (Sensors, solenoids, PSM Assey, mode switch, etc)



Parts Selection - High Performance Builds (more rows to be added later)

PartLocationRationaleAddl Info
Sonnax Pinless Acc PistonsCase / VB / 1-2 Acc HsgPinless accumulator piston kits eliminate the pins used w/stock pistons, eliminating a source of wear and leakageCan be purchased individually or as part of the 4L60E Sure Cure kit
Sonnax or Superior Tech Billet Servo kits (2nd and 4th gear)Servo - CasePair with a HP wide band to maximize clamping force for high HP/Torque applicationsCan be bought individually for 2nd and 4th gear based on need/preferences
Central Valve Bodies AFL valveValve bodyAFL valves can get worn - CVBs drop in replacement restores valve-bore sealing integrity to like newWorn AFL valve will result in AFL pressure loss to solenoids and eventually shorten clutch/band life
Fitzall TCC Regulator ValveValve BodyConverts PWM to On-Off and seals up valve-boreWorn TCC valve will wear converter clutch and trigger P1870 to set/store

*** If your vehicle is equipped w/active cylinder mgmt and/or VVT, you must leave TCC PWM active
Transgo Unbreakable Pump RingsPump BodyDuctile Iron pump rings eliminate a common point of pump failure in high RPM applicationsComes w/updated priming spring for better slide stability at higher RPMs - works in 700R4s and 4L60/65/70/75Es
Sonnax 4L60E-LBPump CoverFactory valve are worn; Sonnax valve provides 10% line pressure increase over stock diameter valveTransgo makes an equivalent but does not have an o-ringed sleeve
Slug or tightly bound coil spring (extra boost valve pump spring works)Valve bodyUse a slug to block movement of 3-2 downshift valve for crispr 3-2 down shifts - delete 3-2 downshift spring and set asideUse 3-2 downshift valve spring inside AFL valve spring to increase AFL pressure delivered to solenoids
Fender washers1-2 accumulator housingShim 1-2 accumulator for crisper/firmer shifts when running a high stall converterDimensions to follow
Sonnax Sure Cure KitVariousHas various performance parts (pinless accumulators, boost valve, coated bushings, etc)Recommended for high performance when paired with other parts/mods
Sonnax Drum Reinforcement Sleeve kitForward DrumStrengthens forward drum at base of input shaft female splines - comes w/Sonnax billet coast clutch pistonUse when power levels are north of 400 but less than 550 or so
4L65/70 Input DrumForward Drum4L65/70Es have an induction-hardened input shaftUse when power levels are north of 400 but less than 600 or so - Sonnax reinforcement sleeve kit should also be added for extra durability
Sonnax Smart Tech DrumForward DrumReplaces factory drum assembly; heavy duty input shaft and reinforced stator locationUse when power levels are north of 550 and/or full race (frequent 5000+ RPM exposure)
Sonnax Billet 6-pinion planet - gear ratio change kitCaseReplaces forward ring gear, planet, sun gear - narrows gear ratio spacing between first and second gearMany racers lose power between 1st and 2nd w/700R4s and 4L60Es due to the wide ratio between first gear (3.08-1) and 2nd gear (1.51-1) - Sonnax kit changes 1st gear to
Sonnax Smart ShellCaseBest sun shell on market. Can fully rollerize the mid-case when paired with an 03+ reaction shaft w/bearingUse an 07+ 4L70E induction hardened reaction shaft for high performance in any 700R4 or 4L60E
5-pinion planetary carriersCaseUse when power levels exceed 400 and/or RPMs exceed 5000

Install OEM Carriers only!
Debatable whether this is mandatory at those levels however can be installed in any year 700R4 or 4L60E


Performance Mods (more rows to be added later)
I very rarely use shift kits for most transmissions as much can be accomplished without them, especially if you have the transmission apart on the bench.

ProcedureLocationInstructionsAddl Info
Hole size for 1-2 shiftSeparator plateDrill 1-2 feed hole based on converter stall, final drive ratio, vehicle weight, desired shift firmness and 2nd Gear Servo Type installedAll things equal, the more apply surface area your 2nd gear servo has, the smaller the hole size you need to drill to accomplish a given level of ‘firm’

Example: 3000 stall converter in an F-body w/4.11 gears with a Sonnax Super Hold 2nd gear servo installed should have a .86-.90 1-2 feed hole in the plate to start.

Use factory 1-2 accumulator setup then shim 1-2 accumulator to firm up shift
Hole size for 2-3 shift and 2-3 exhaustSeparator plateDrill 2-3 feed and 3-2 exhaust to .093-.120 depending on converter stall, final drive ratio, vehicle weight, desired shift firmness.093 is fine for stock to mid-2000s stall - go .100-.110 for anything 2500-3000 and .112-.125 for anything north of 3000

Keep load release springs in the drum if clearance is .030-.040 and RPMs exceed 5000
Hole size for 3-4 shiftSeparator PlateDrill to .093-.123 based on stall speed, final drive ratio, vehicle weight, presence or absence of 4th accumulator circuit based on modsSee next row for 4th accumulator mods
4th accumulator mods - restrictCase - 4th accumulator piston boreRestrict 4th accumulator by installing old 4th acc piston upside down in bore w/no seal installed (grind off app ⅓ of legs first)

Install new 4th acc piston w/new seal and mesh legs w/old one
This restricts 4th accumulator oil by 90% and allows most to flow directly to the 4th gear apply servo piston to obtain overdrive

Use for when converter stall is less than 3000
4th accumulator mods - deleteCase - 4th accumulator piston boreDrive ¼ inch check ball into 4th accumulator feed orifice in bottom of piston bore

Leave piston, spring and pin and 4th acc check ball out
This mod is permanent

Use for all stall speeds 3000+ where racing may take place in overdrive (usually not recommended to race in OD)
2-4 Band ClearanceCase - Rev Input DrumKeep band clearance to ⅛” longitudinal travel (band on drum) for optimal life and shift quality
3-4 clutch pack setupForward DrumSet clearance to .030-.050 for all applications using stock number of frictions; add .010 for each additional friction up to two (2) then stop

Max clearance should be .060 regardless of number of frictions installed

HP/5000+ RPMs - keep load release springs in; use Transgo’s high rate return spring kit w/bleeder orifice
Drain BackPump BodyDrill drain back port to 5/16” on all high performance or heavy duty applications
Pump MachiningPump Body and CoverMachine pump cover on a lathe to make flat (take .010 off)

Machine pump body deck surface on lathe to make flat (take .010) off

Machine pump rotor/slide pocket to depth such that clearance between rotor and slide to deck is .002”
Check for run out on stator/pump cover while on lathe - if stator was swapped previously and not installed on a press, chances are it’s not installed perfectly square
Reverse Input DrumCaseReplace or resurface reverse input drum so wide band (Red or Kevlar-lined) can be installedUse a Kevlar lined band for anything super duty / full race or serious street strip
Sun GearsCaseCut four small shallow grooves at the 3-6-9-12 o’clock positions on both sides of rear sun gear and planet-facing side of forward sun gearThis increases lube flow to the captured bearings in both planetary carriers for better longevity and heat dissipation
Low-Reverse and Reverse Input Clutch Packs

(Race Only - No Street)
CaseLow Reverse - remove 3 friction discs and install tubular steels in their place

Reverse Input - remove two friction discs and install tubular steels in their place
This weakens the reverse clutch but reduces drag while moving forward - not recommended for street driven vehicles

More to come....
 
Last edited:

618 Syndicate

You won't...
Supporting Member
Joined
Sep 17, 2020
Messages
6,761
Reaction score
15,892
Location
Southern Illinois
So, the conventional wisdom across this site and many others is that the 60 is not suitable for performance upgrades, that it's barely enough for a stock small block/LS motor.
Why is it that so many people have come to this conclusion, and you think it can be built to live with more than stock power? Not being a smartarse, genuinely interested in your reasoning.
 

NickTransmissions

Supporting Member
Supporting Member
Joined
Aug 16, 2023
Messages
673
Reaction score
1,081
Location
Las Vegas
So, the conventional wisdom across this site and many others is that the 60 is not suitable for performance upgrades, that it's barely enough for a stock small block/LS motor.
Why is it that so many people have come to this conclusion, and you think it can be built to live with more than stock power? Not being a smartarse, genuinely interested in your reasoning.
TLDR answer to your question: Uninformed (ie without sufficient context) group think with little-to-no first hand knowledge of what they're talking about, IMO.

Longer answer:

If we are talking about bone stock 4L60Es, particularly those built before 2001, then yes, the factory handicapped them to a large extent when it comes to being ready for performance as-is compared to a 4L80E in stock form. However, with a few relatively minor changes, they can be built to handle power within reasonable limits (i..e 500 hp or less is a general consensus guideline amongst most of us) before you have spend a near infinite amount of money to get them to hold up.

Stock 4L60Es experience chronic, repeated failures of the 3-4 clutch due to its poor design and set up. This probably drives the majority of the voices telling everyone 4L60Es are made of glass and to use a 4L80 for anything beyond stock applications (and can't blame them if so). But context is everything and weighing cost/benefits when it comes to swaps is critical to making the right call...So here's more context:

4L60E Factory Design Flaws that have been driving the negative opinion/views on their durability:
> Under-designed 3/4 clutch; smaller surface apply area and not enough individual frictions to make up for it compared to peer transmissions from Ford and Dodge (AOD/4R70/75W and Dodge 46RH/RE) - makes 3/4 pack very vulnerable to premature failure
> Insufficiently sized feed orifices in the spacer plate for 1-2, 2-3, 3-4 shift feeds - lengthens overall dwell time between clutch command and full compression shortening clutch pack life
> Undersized 2nd gear apply servo piston (553 servo) installed in majority of applications (corvette servo began to appear in Corvettes, F-bodies and later proliferated to high-end sub-models of some of the trucks and SUVs in later years) combined with excessive band clearance and a band that's too narrow relative to drum surface area (shorter 2-4 band life then otherwise)
> Excessive clearance in 3-4 clutch pack (.060-.080) combined with unnecessary load release spring assemblies (intended to solve a non-existent problem of centrifugal apply while creating a very real one in premature clutch burn up)
> Decision to use a steel input shaft pressed into an aluminum drum with no reinforcement at shaft/drum junction, resulting in drum leaking at apply circuits in shaft
> Accumulator circuits designed to absorb too much shift energy, lengthening dwell time between clutch command and full compression (shortens clutch life)
> Weak metal used in the construction of the sun gear reaction shell resulting in numerous failures (loss of rev, 2nd and 4th gears)
> Pulse Width Modulation in TCC apply strategy too soft/gradual (95+) - shortening TC life

Simple 4L60E Corrective Measures that address all of the above and give the '60 a fighting chance in a performance application:
> Set up the 3-4 pack w/.030-.040 clearance w/load release springs or .040-.050 for more mild builds and delete the load release springs
> Truncate 1-2 and 3-4 accumulation by simply installing $40 dollar shift kits or your own mods (usually less than $10 in raw materials)
> Install a corvette (093) 2nd gear servo in place of factory 553 for all 4L60Es - $12.00
> Install a wide 2-4 band in all builds - $10-12 more than the factory spec 2-4 band (resurface existing reverse input drum to accommodate - $30)
> Drill out the 1-2, 2-3 and 3-4 feed orifices per converter stall; if factory 1600-1800 and corvette 2nd gear servo installed, go .076-.086 on the 1-2, .093-.100 on the 2-3 and .093-.100 on the 3-4
> Convert the PWM TCC apply to an on-off using a Fitzall valve designed specifically for that purpose ($9.00)
> Install a hardened/heat treated sun gear reaction shell on all overhauls - $40ish (Sonnax or TCI rollerized, reinforced shells for high HP/HD applications - $150)
> Cut lube passages in both sun gears on the planet-facing side to allow addl lube flow to planetary carrier bearings and pinion gears
> Install Sonnax fwd drum reinforcement sleeve kit on applications 450-500 HP and RPMs expected to exceed 5,000 frequently (unless Sonnax smart tech drum is used - it comes w/reinforcement installed, bolt-on 3-4 backing plate and hardened steel input shaft)

The above mods take a trans capable of dealing with 250-275 HP and allow it to comfortably handle up to 400-500HP, depending on which above mods are done and overall vehicle profile/application, etc (Sonnax Smart sun shells are used in 600+ HP street/strip vehicles and work great).

Myself and other builders I know personally have 700R4s and 4L60Es behind everything from 383 SBCs to built LS1s, 5.3s, 6Ls and the like making upwards of 500HP street/strip/race/etc and I personally have yet to actually have one come back other than occasionally for a refresh (i.e. the trans was working/functioning so the refreshes are proactive instead of reactive).

In my opinion, the cost benefit favors a 4L80E swap in any one (or more) of the following scenarios:
> Engine power / torque exceeds 550HP/TQ and / or engine torque curve peak is in the 3000-4500 neighborhood if power/torque are 450+ HP/TQ
> Vehicle will be towing/hauling in excess of 6,500-7,000 lbs+ frequently, especially out West
> Vehicle weight increases substantially over stock GVW for some reason
> Vehicle will be used predominantly in a HD specialized application such as snow plow trucks
> Engine will spin more than 7,000 RPMs consistently (full race, mud bogging, etc)

4L80E Benefits: With minimal mods the 4L80E can handle 750-800HP/Tq...I typically just dual feed the direct clutch, install a billet rollerized forward hub (Costliest mod at only $150-$200), rollerized output shaft-case thrust, shim the two planets as well as the forward hub-direct drum thrust to take out the slop, block off the 2-3 and 3-4 accumulator plate, install a Chrysler A518 direct clutch snap ring in place of the stock int. snap ring, install high rate return springs in the intermediate and direct clutch piston, drill out various lube orifices (free), install a Sonnax boost valve, CVBs AFL and TCC reg valve, drill the spacer plate per vehicle application, weight, final drive, stall, desired shift firmness and set clutch clearances as they need to be. Beyond 800 or so, you'll be installing lots of billet parts and bill goes up by literally $2500-3000 or more when power levels approach that 800 HP mark compared to what it takes to prep one for sub-800HP vehicles.

4L80E Swap cost drivers: You have to integrate the 4L80e into a vehicle that originally took a 4L60 (Driveline cut/rebalanced, x member moved, etc), reprogram the PCM via segment swap (HP Tuners) and purchase an external harness adaptor. 4L80E rebuild kit and parts are appx 40% higher than a 4L60e (bushings, clutch and steel modules, bands, paper, rubber, seals, one-way clutch assemblies, etc)

Additionally, the 4L80E consumes about 15% more crank horse power to turn than a 4L60 so that by itself makes me hesitate do encourage swaps outside of specialized situations where engine power is 450HP or less, which is the majority of engines that would be mated to either transmission. A 4L60E can be built for much less overall combined costs and will work just fine if done correctly and vehicle/trans is well maintained.

That should bring a more balanced perspective to the issue while clearing up some of the confusion around what folks typically say about the 60 for anything beyond stock and why some builders like myself push back a little on that notion.

As always, context is everything.

Hope it helps...
 

618 Syndicate

You won't...
Supporting Member
Joined
Sep 17, 2020
Messages
6,761
Reaction score
15,892
Location
Southern Illinois
Definitely helpful.
I don't dismiss lived experience as uninformed, the interwebs are littered with accounts of supposedly built 60's that failed or grenaded under the conditions for which they were built. I doubt they're all lying...
That said, I'm willing to accept that a 60 isn't as fragile as some would have you believe.
Thanks for sharing your perspective.
 

NickTransmissions

Supporting Member
Supporting Member
Joined
Aug 16, 2023
Messages
673
Reaction score
1,081
Location
Las Vegas
Definitely helpful.
I don't dismiss lived experience as uninformed, the inter webs are littered with accounts of supposedly built 60's that failed or grenaded under the conditions for which they were built. I doubt they're all lying...
That said, I'm willing to accept that a 60 isn't as fragile as some would have you believe.
Thanks for sharing your perspective.
Thank you.

Inter webs is littered w/transmission failures of all types and descriptions but you wont see anywhere near the amount of success stories (victory has a thousand fathers where failure is an orphan, something like that). I've seen (and read accounts of) plenty of 80s as well as many other transmissions that also suffered the same fate as well as tearing down/inspecting many of both transmission types personally. Some of those were victims of lack of maintenance, some had unexpected parts failures and/or were pushed beyond what they were capable of handling, even with the mods/upgrades, etc.

That said, the 4L80 is simply a much stronger trans than the 4L60 (really, it's night and day) so you won't see nearly as much chatter about them failing (would be really weird if so, right?).

It all goes back to cost, risk & benefit but sometimes the line is much more blurry than others when it comes to choosing between a 4L60E and a 4L80E. So when talking with customers who are contemplating a swap, I try to present the merits, pros and cons of both as applied to what the customer has going on and, through conversation and deliberation, jointly come up with what we both feel is the right way forward.
 

62barsoom

I'm Awesome
Joined
May 9, 2021
Messages
447
Reaction score
930
Location
US
WOW again! Another fantastic bit of knowledge sharing. I thank you sir, for sharing. A question if I may. I'm picking up a 99 5.7 Tahoe Thursday. It has 192,000 miles on it. The last owner hit the highway without checking the oil and roached the motor. That doesn't give me warm fuzzies about the state of the transmission. I'm 67 and have been an amateur wrench since my neighbor picked me up to see the red-hot manifold on his model A. I'd like to go through the thing while I've got the motor out. I've never been into one. Think it's something I could handle. I've read that they really require a bit of experience to do right. No power adders but I'd rather not be in it during the winter. Dependability is the goal. Super clean truck, unheard of here in the West Virginia mountains.
Again thanks!
 Jim
 

NickTransmissions

Supporting Member
Supporting Member
Joined
Aug 16, 2023
Messages
673
Reaction score
1,081
Location
Las Vegas
WOW again! Another fantastic bit of knowledge sharing. I thank you sir, for sharing. A question if I may. I'm picking up a 99 5.7 Tahoe Thursday. It has 192,000 miles on it. The last owner hit the highway without checking the oil and roached the motor. That doesn't give me warm fuzzies about the state of the transmission. I'm 67 and have been an amateur wrench since my neighbor picked me up to see the red-hot manifold on his model A. I'd like to go through the thing while I've got the motor out. I've never been into one. Think it's something I could handle. I've read that they really require a bit of experience to do right. No power adders but I'd rather not be in it during the winter. Dependability is the goal. Super clean truck, unheard of here in the West Virginia mountains.
Again thanks!
 Jim
Hi Jim, I'm sure you'd be fine - refer to my 4L60E Video Series on Youtube for step by step procedures plus mods for performance to get a good idea of what' involved. Trans probably needs an overhaul and since it's out, I'd definitely go through it now vs dealing with it after the fact.

You'll need a few specialty tools, including:

- holding fixture (can be bench mounted or adapted for mounting to an engine stand like the one I use)
- Clutch spring compressor(s) - there's a few universal clutch spring compressor tools that will work on all of the return spring assemblies in the 700R4/4L60Es
- Sealing ring expander and sizer - these make the job efficient and reduce the risk of breaking a sealing ring however you can improvise by using a hose clamp w/ the pump cover/stator to size the sealing rings in place once you've got them in their respective grooves on the stator
- Bushing Driver set for all bushings - alternatively you can take the new bushings w/all the parts that take them to a local trans shop for r/r; expect to pay $125-150 or so
- Dial indicator and magnetic base for measuring front end play - keep it between .015-.025
- Feeler gauges for measuring clutch clearance in the forward, 3-4 and reverse input clutch - you can also use a dial indicator in combo with a piece of steel laid over the drum while you put the rev input drum and forward drum on the pump and force compressed air into the applicable feed circuits while you measure clutch pack travel from rest to fully applied (keep your 3-4 clearance between .030 and .050, forward clearance to .030-.050 and rev input clearance to between .050-.070
- Pump half alignment tool - you can use a giant hose clamp from Ace Hardware or Home Depot - then test it on the empty case once the pump is assembled and install the pump onto your torque converter to make sure the rotor turns freely
- Inch lb torque wrench (you prob already have this)
- Torx Plus 50 socket for your bell housing-case bolts - Use a 1/2 inch drive impact and 6" 1/2 drive extension with a 1/2-3/8 drive adaptor so you can more easily remove those bolts from the case; if they still won't come out, heat the case side of the threads with a small propane torch for a minute or so then try again and they will eventually come out
Have the pump resurfaced and pocket cut so that your rotor and slide to pump body deck surface clearance is .0015-.002 (pump rotor needs .001-.0015 and slide needs .001-.002).

Turn reverse input drum .010 undersize to restore band surface then obtain 1/8" longitudinal travel of the band when on the drum and servo assembly installed

Separator plate shift calibration adjustments: Drill the 1-2 feed .072-080, 2-3 feed, 3-4 feed and band release to .093 and low reverse to .080-093 depending upon how often you'll be manually shifting to and out of manual low (if never, leave the feed hole stock size)

There's a boat load of tips/tricks but for now, start watching my vids and post your follow up questions here so we can keep the info exchange going.

OR or you can swap in a Hydromatic :)
 

NickTransmissions

Supporting Member
Supporting Member
Joined
Aug 16, 2023
Messages
673
Reaction score
1,081
Location
Las Vegas
Couple More 4L60/65E videos (Will edit this post as I upload more vids):

4L60E Transgo HD2 Shift Kit Installation
xc_hide_links_from_guests_guests_error_hide_media
 
Top