4L60E Information Thread

[Joe Dirte]

LOL, yea you get some odd responses on the net sometimes.

How come you're going back to the '60 for a while? Are you rebuilding your 4L80E?

Wanted truck runnin n couldn't find a good 80 anywhere near me. Was originally a 60 truck n found a good one in yard. Won't be seein any heavy duty use. Mainly wanted my 4wd back for winter comin n take time to go thru the 80 since it had weak reverse.

 

[NickTransmissions]

Wanted truck runnin n couldn't find a good 80 anywhere near me. Was originally a 60 truck n found a good one in yard. Won't be seein any heavy duty use. Mainly wanted my 4wd back for winter comin n take time to go thru the 80 since it had weak reverse.

Weak reverse could be worn/tired apply piston sealing ring (there's one large rubber o-ring on the apply piston and then two smaller o-rings on the 1-2 accumulator piston that nests inside of it. Not sure what sort of mods you may or may not want to do to the 80 but you can check out my 4L80E High Performance Build video series for some ideas...I built it for an 650-700 HP twin turbo 02 Sierra so there may be some stuff you prob don't need but the procedures themselves are mostly the same as any mild performance build.

 

[RichLo]

Just wondering, what's your views on the resistor shift kit to increase line pressure on a stock transmission?

I've done it on a few 4l60's and I like the added firmness and feeling that I'm saving the clutches from slop wear but I never know if I'm prematurely wearing something else out instead.

 

[NickTransmissions]

Just wondering, what's your views on the resistor shift kit to increase line pressure on a stock transmission?

I've done it on a few 4l60's and I like the added firmness and feeling that I'm saving the clutches from slop wear but I never know if I'm prematurely wearing something else out instead.

Run a moving line pressure test to see what your pressures are at idle-to-part throttle acceleration the next time you do one...If they're anywhere close to full throttle/WOT levels, I'd remove it and mechanically calibrate your hydraulics instead. To me it's a gimmick to fool the ECM via continuity manipulation into commanding max line pressure at all times so it's maxed for part throttle shifts. Basically the electronic equivalent to blocking off the line bias valve in the 700R4 and 200-4R that gives you like 125-150 PSI put-putting around in the parking lot. TCI's constant pressure valve bodies do the same thing via physical mods to the VB and pump.

Unless you're racing or super heavy duty towing/hauling where at or near max LP is needed at all times, I'd remove it, install a Sonnax boost valve or Transgo equivalent so that you get boost pressure when you need it (heavy acceleration) and save your pump, hard parts, keeping them healthy for the long run.

My .02.

 

[pwesley]

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...

You seem to be extremely knowledgeable about the 4L60E transmission. Maybe you could give me some direction as I am stuck. My truck has no cel, won't communicate with scanner, shifts fine when cold but once the engine warms up it goes back into limp mode. We checked all fuses, replaced ignition switch, looked for bad wires, swapped out the computer, and simply don't know what to do next. If you can advise me with anything at all, it would be greatly appreciated . Thanks so much!

 

[NickTransmissions]

My truck has no cel, won't communicate with scanner,

To clarify, you have no comms between the pcm and scan tool when its plugged into the ODB port and key is "on" but engine is off?

 

[pwesley]

That is correct

 

[NickTransmissions]

That is correct

Ok...Check your fuse box in the engine bay for the cig lighter fuse...it may be blown. It's a 15 amp fuse towards the right-middle of the box if you have a 2001-2006 (and prob similar/same for other years).

You must be registered for see images attach

You must be registered for see images attach

 

[pwesley]

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.

 

[pwesley]

It drove fine coming home. I stopped to turn in my driveway, and it wouldn't go. But it shifted just fine before that. Just all of a sudden.... don't know why. My husband told me to put it in 4L, and it went then and got me into my driveway. Now it has drive and reverse. Won't shift like its supposed to. And she won't communicate with scanner either.