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
4L60E Rebuild Series (Stock level build)
4L60E Rebuild Series (High Performance)
4L60E Valve Body Tips and Tricks
Vintages and Interchange Information
The following information applies to all 4L60E-equipped models and sub-models unless otherwise noted.
A Few Common Problems, Causes and Solutions (I will add to this list as I go)
Parts Selection - Updating (Stock to mild builds)
Parts Selection - High Performance Builds (more rows to be added later)
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.
More to come....
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
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4L60E Rebuild Series (Stock level build)
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4L60E Rebuild Series (High Performance)
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4L60E Valve Body Tips and Tricks
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Vintages and Interchange Information
The following information applies to all 4L60E-equipped models and sub-models unless otherwise noted.
| Vintage | Components | Interchange Information | Additional Context |
| 1992-1994 |
| 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 |
Valve body castings have provision for PWM solenoid however no PWM solenoid is installed for 1992-1994 |
| 1995 |
| Not interchangeable with any other year without swapping the following parts w/year-applicable ones:
| 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 |
| 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 |
| 1993-2000 | Separator plate gaskets | Interchangeable 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) |
| 1996-2003 | Manual Lever Position Sensor (first design) | Will interchange between all years at left | First 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-L2008 | Manual Lever Position Sensor (second design) | Will interchange between all years at left but WILL NOT interchange with vehicles manufactured for model years 1992-2003 | Second design uses one electrical connector instead of two, integrating Park and Neutral into one channel for data comms w/the PCM |
| 2001-2006 | Separator plate gaskets | Interchangeable 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 |
| 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 Corvette | 300mm 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 |
| 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+ |
| 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/Symptom | Cause | Fix | Notes |
| 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 failed | Check 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 gear | Sun 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 work | Lip seals on reverse input piston and/or low reverse piston worn | Replace lip seals on overhaul | Common 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 works | Input 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-ground | Confirm 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 third | 2nd gear Servo piston/sealing rings Worn/burnt 2-4 band | Replace rings or Servo assembly w/093 servo | Air check 2nd gear apply to confirm / deny the servo is the problem |
| No forward movement in any range setting - reverse works | Failed low roller clutch | Replace roller clutch assembly | Check center support for cam or lug damage - replace if necessary |
| Tie Up at 1-2 shift | #1 Check ball stuck in plate | Repair plate using Fitzall repair sleeve and install torlon check ball | Common for all years, sub-models |
| Late Harsh 1-2 shift AND P1870 | TCC 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 vehicles | If 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 stored | 1-2 accumulator springs broken | Replace broken springs, piston and seal | Transgo 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 1 | Input sprag | Replace input sprag gear assembly | 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 |
| Slipping / neutral during 2-3 shift | 3-4 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 mode | Diagnose and fix causes which can be
| Limp mode - third and reverse only (no other gears accessible) |
| Third gear starts after rebuild | Input drum stator base O-ring (Green) left out or cut | Green o-ring segregates forward and 3-4 apply circuits | Install 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 rebuild | 4-3 relay valve installed backwards | Put valve in the right way | Applies to the 700R4 as well |
Parts Selection - Updating (Stock to mild builds)
| Part | Location | Rationale |
| Accumulator pistons | Valve body/Case/1-2 Acc Hsng | Always replace old acc pistons with new as they wear at the pin bore and cause leaks in their respective circuits |
| Torlon Check balls | Case / Valve Body | Use 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-LB1 | Pump (Boost valve) | Preexisting boost valves are worn; Sonnax boost valve and spring kit provides 10% increase in linear line pressure |
| Corvette Servo (093) | Servo | Has 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 assy | Forward Drum | Retro 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 Drum | Factory-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 plate | Forward Drum | Provides 7 frictions and steels in the 3-4 clutch pack; Alto, Borg Warner and Raybestos also make equivalent kits |
| Pump kit | Pump | Comes with new rotor/slide/vanes, rings, small parts |
| Bushing Kit | various | R/R all bushings in the unit |
| Sun Shell | Case | Obtain a hardened and heat treated version |
| Forward Sprag / Low Roller Clutch | Input Sprag Assy / Center Support | Replace with new Borg Warner counterparts |
| Electrical components | Valve body-Pan area | Always replace all electrical components (Sensors, solenoids, PSM Assey, mode switch, etc) |
Parts Selection - High Performance Builds (more rows to be added later)
| Part | Location | Rationale | Addl Info |
| Sonnax Pinless Acc Pistons | Case / VB / 1-2 Acc Hsg | Pinless accumulator piston kits eliminate the pins used w/stock pistons, eliminating a source of wear and leakage | Can be purchased individually or as part of the 4L60E Sure Cure kit |
| Sonnax or Superior Tech Billet Servo kits (2nd and 4th gear) | Servo - Case | Pair with a HP wide band to maximize clamping force for high HP/Torque applications | Can be bought individually for 2nd and 4th gear based on need/preferences |
| Central Valve Bodies AFL valve | Valve body | AFL valves can get worn - CVBs drop in replacement restores valve-bore sealing integrity to like new | Worn AFL valve will result in AFL pressure loss to solenoids and eventually shorten clutch/band life |
| Fitzall TCC Regulator Valve | Valve Body | Converts PWM to On-Off and seals up valve-bore | Worn 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 Rings | Pump Body | Ductile Iron pump rings eliminate a common point of pump failure in high RPM applications | Comes w/updated priming spring for better slide stability at higher RPMs - works in 700R4s and 4L60/65/70/75Es |
| Sonnax 4L60E-LB | Pump Cover | Factory valve are worn; Sonnax valve provides 10% line pressure increase over stock diameter valve | Transgo makes an equivalent but does not have an o-ringed sleeve |
| Slug or tightly bound coil spring (extra boost valve pump spring works) | Valve body | Use a slug to block movement of 3-2 downshift valve for crispr 3-2 down shifts - delete 3-2 downshift spring and set aside | Use 3-2 downshift valve spring inside AFL valve spring to increase AFL pressure delivered to solenoids |
| Fender washers | 1-2 accumulator housing | Shim 1-2 accumulator for crisper/firmer shifts when running a high stall converter | Dimensions to follow |
| Sonnax Sure Cure Kit | Various | Has various performance parts (pinless accumulators, boost valve, coated bushings, etc) | Recommended for high performance when paired with other parts/mods |
| Sonnax Drum Reinforcement Sleeve kit | Forward Drum | Strengthens forward drum at base of input shaft female splines - comes w/Sonnax billet coast clutch piston | Use when power levels are north of 400 but less than 550 or so |
| 4L65/70 Input Drum | Forward Drum | 4L65/70Es have an induction-hardened input shaft | Use 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 Drum | Forward Drum | Replaces factory drum assembly; heavy duty input shaft and reinforced stator location | Use when power levels are north of 550 and/or full race (frequent 5000+ RPM exposure) |
| Sonnax Billet 6-pinion planet - gear ratio change kit | Case | Replaces forward ring gear, planet, sun gear - narrows gear ratio spacing between first and second gear | Many 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 Shell | Case | Best sun shell on market. Can fully rollerize the mid-case when paired with an 03+ reaction shaft w/bearing | Use an 07+ 4L70E induction hardened reaction shaft for high performance in any 700R4 or 4L60E |
| 5-pinion planetary carriers | Case | Use 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.
| Procedure | Location | Instructions | Addl Info |
| Hole size for 1-2 shift | Separator plate | Drill 1-2 feed hole based on converter stall, final drive ratio, vehicle weight, desired shift firmness and 2nd Gear Servo Type installed | All 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 exhaust | Separator plate | Drill 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 shift | Separator Plate | Drill to .093-.123 based on stall speed, final drive ratio, vehicle weight, presence or absence of 4th accumulator circuit based on mods | See next row for 4th accumulator mods |
| 4th accumulator mods - restrict | Case - 4th accumulator piston bore | Restrict 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 - delete | Case - 4th accumulator piston bore | Drive 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 Clearance | Case - Rev Input Drum | Keep band clearance to ⅛” longitudinal travel (band on drum) for optimal life and shift quality | |
| 3-4 clutch pack setup | Forward Drum | Set 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 Back | Pump Body | Drill drain back port to 5/16” on all high performance or heavy duty applications | |
| Pump Machining | Pump Body and Cover | Machine 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 Drum | Case | Replace or resurface reverse input drum so wide band (Red or Kevlar-lined) can be installed | Use a Kevlar lined band for anything super duty / full race or serious street strip |
| Sun Gears | Case | Cut 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 gear | This 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) | Case | Low 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....
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