4L60E Information Thread

[NickTransmissions]

We even tried a different scan tool, still nothing. Swapped out the computer with an exact match, nothing changed. Bought a new ignition switch, no change. And that thing was a demon to replace! But did no good. Shifts fine at first start up, like for the first mile or so, then goes back to limp mode.

Well this is really weird - I responded to your post #12 but this is what I saw when checked the thread again...I have absolutely no idea why my reply below would warrant review by moderators but the site has been acting a bit strange as of late...

You must be registered for see images attach

 

[pwesley]

Well this is really weird - I responded to your post #12 but this is what I saw when checked the thread again...I have absolutely no idea why my reply below would warrant review by moderators but the site has been acting a bit strange as of late...

You must be registered for see images attach

I have no clue about moderators and stuff, but I do appreciate any help at all, so thank you. My name is Pam, by the way. So I showed this picture you sent to my husband and he is gonna check this. It would be great if it was something as simple as a fuse. Changing that ignition switch was a demon! I will let you know what we find here shortly. Thanks for responding!!

 

[NickTransmissions]

I have no clue about moderators and stuff, but I do appreciate any help at all, so thank you. My name is Pam, by the way. So I showed this picture you sent to my husband and he is gonna check this. It would be great if it was something as simple as a fuse. Changing that ignition switch was a demon! I will let you know what we find here shortly. Thanks for responding!!

You're welcome, Pam. The fuse isnt likely to fix the transmission's odd behavior as that is indicative of a short somewhere else, either in the trans (trans harness, solenoids, pressure switch manifold) or in the external harness. Hopefully replacing the fuse restores comms between the pcm and scan tool for you.

 

[pwesley]

Ok. My husband just went to check that and my truck doesn't have a 15A fuse like in the pic. Here is what mine looks like

You must be registered for see images attach

 

[pwesley]

The 20A ecm-b fuse is good. The fuses for ecm-1 , aux, are all good as well.

 

[pwesley]

The 20A ecm-b fuse is good. The fuses for ecm-1 , aux, are all good as well

 

[NickTransmissions]

The 20A ecm-b fuse is good. The fuses for ecm-1 , aux, are all good as well.

You will need to obtain a fuse block diagram or similar info for your year vehicle (don't think you provided that but not 100% sure) so you can see what fuse is associated with the OBD port / cigarette lighter but in my 03 Tahoe when that fuse blew I lost comms w/the PCM via the OBD port and was resolved when I replaced the fuse.

 

[azreeal]

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.

Vintage	Components	Interchange Information	Additional 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
1993-2000	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	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 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	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/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 Internal Harness Ext Harness Solenoids Pressure Switch Man / IMS	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....

Excellent write up!!

 

[Wilecoyote]

Now and then when I start the truck there is a bang/shook in park. I can shift it to neutral and start it and never does it?

 

[NickTransmissions]

Now and then when I start the truck there is a bang/shook in park. I can shift it to neutral and start it and never does it?

What do you mean by "bang/shook"? Describe the symptom(s) in detail. And are you asking whether or not the same symptom happens in neutral? I think you're making a statement there but see a question mark so want to clarify.