Frank has added an Up-Shift assist Spring to the 2-3 Shift Valve-Train.
This was originally accomplished Hydraulically and without the aid of Spring assistance (unlike the 1-2 Shift Valve-Train that uses a Spring).

The 1-2 Up-Shift uses an assist Spring in Factory form because the Shift is Non-Synchronized, and can be accomplished very quickly.
The 2-3 Up-Shift does not use an assist Spring in Factory form because the Shift is Synchronized, and must be accomplished slowly for the Shift to execute properly.

This Synchronized 2-3 Up-Shift involves the Release of the 2-4 Band and the Apply of the 3-4 Clutch... they much be timed properly.
Otherwise a Bind or Flare will occur on the Up-Shift.

The Design of these Shift Elements and the corresponding Power-Flow are very old, originating in the 1982 THM700-R4...
And in actuality, Hydraulically originating in the 1981 THM200-4R.

After such a long history, many builders experimented and determined; that should the 2-4 Band clearance and the 3-4 Clutch clearance be significantly reduced...
We can speed up the 2-3 Up-Shift tremendously, maintain a Synchronous Shift, and not suffer a bind or flair.

Frank does exactly that, and implements this very simply with control from stock Hydraulic designs and the added 2-3 Valve-Train assist Spring.
It creates a great, positive, and VERY fast 2-3 Up-Shift!
As far as we know, He is the only Builder to have Engineered this method.

Most everyone else has copied my Father's design (which also applies to the THM700-R4 and THM200-4R).

In the 4L60E/ 65E/ 70E, this occurs with control from Hydraulic changes to the 3-2 Control Valve and the 2-3 Accumulator Check-Ball Passage, as shown in the Diagram above.

The Purple passages are Blocked off, the #2 Check-Ball gets omitted and the Hole Blocked.
Now Flow to the 2-4 Servo is only Regulated by the Orifice size in the Separator Plate (next to blocked #2 Check-Ball Hole).

Getting this Orifice Size correct for the DIY Builder can be VERY frustrating!!!
But when done properly...
The 2-3 Up-Shift will be the Most Positive, Quick, Firm and Powerful SHIFT (2-3) that can be achieved!

There is much more to trying to time the 2-3 Up-Shift this way.
Line pressure, Servo Type, Servo Cushion and Return Spring type, Orificing for 2nd Feed, Third Feed, Third Accumulator Feed (Band Release), Third Exhaust, clearances for the 2-4 Band, and 3-4 Clutch all play a role.

In my opinion, Frank looked at the complicated mess that everyone had been copying...
And he came up with the most simple (and user/ DIY) solution that works nearly as well as doing it the Hard way!
Frank has really been showing off his Brilliance!
And it's great!!!

 

My trans is setup this way, slug in the check ball hole and orifice sized just right. My 2-3 shift is awesome

 

Bind ? I had bind with my 6sp when u braking with foot on accelerator )
But for 4l60e it can be only with transbrake as far as I understand it working
Because if band not released properly it will be 4th
So it will be 2-4-3 shift with loss of acceleration but not that bad as 5+ trannys with ruined synchronizing between clutches


I thought about blocking #2 checkball
But mostly for enlarging band release(and with blocked it will be band engagement too) big enough to achieve more fast relief 3rd oil from servo to eliminate little flare when im driving at 3rd and push it to 2nd but not floor it
I cant say that it happens a lot -but time to time it happens especially when oil cold
It not a problem actually - I just noticed it and thinks how to make it perfect

I saw that methood
It literally changes ratio of shifter areas forcing shifter move earlier when opposite pressure not drained fully yet
I will check it too
I also wanna make solenoid open more large area of drain orifice inside it to make oil exhaust faster thru solenoid -just for testing
I cant say Im struggling with my 2-3 shift now -it happens right in time and like no gear changed -without positive push
In one way -its good because no additional stress
In another - I wanna make it more rapid -just for my taste
I also use TQ management and at full throttle it eats 30% to make it plain without bump
I think when I installed trashed separator (because it experimental and I dont wanna ruin good one) - it had repair seat for 2nd checkball and because it orifices original hole for checkball I deleted seat and installed 5/16 checkball to make it work
In general it works
But in some scenarios I think too big hole for new checkball allows 2nd oil inside servo excavates too quickly back to 2nd feed line and release band little bit early
Its not often but I feel some delay at medium throttle time to time like 3rd engages too lazy -not a flare but not a solid shift

My idea was to use 3-2 orifice as 2-3 also to exclude couple of shifters from restricted area (all lines after orifice has restricted flow) to make their fluid loss not matter for 3rd apply pressure
And in general it works not bad -it drivable
Just need little polishing
At full throttle its just awesome -like one gear
No bumps and no delays
But if you drive in tight traffic from quick accelerating to relaxing cruising -sometimes it behaves like shouldn't
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I also wanna admit -its my hobby to broke my tranny and rebuild it again )
I read this full thread and many others and remembered who and what to suggest - I like new knowledge ) I also understood good enough how solenoids and shifters work to reverse engineering shift kits and analyze changes that they bring. But anyway thanks to detailed explanation !

 

Disassembled one
Orifice that blocked by ball is about 0.065
Drill it to 0.084 and assembled back
Now oil that pushed 2-3 shifter should drain faster about 67%
Kinda "spring" mod
Installed and drove home today
Can't say it changed much in 2-3 shift speed (because before it also fast)
But lack of positive push at 2-3 still here
Continue testing

 

I once played with the larger orifice and even found a larger ball But within the contraints of the factory solenoid housing , Simply could not get it to work. Pobably why no ones ever made a HI PERF shift solenoid . Idealy a large dump here would be a great idea, But I think a solinoid with this designed in would be nessesary rather than a modded factory. But Good luck, Pperhaps you will have better luck than I did .

 

I intentionally not took bigger ball because bigger ball= bigger area of AFL pressure apply and this will require stronger solenoid
But OEM ball can block much bigger area than it made from factory
I think I will drill my second spare solenoid to 0.093 or 0.100
But for now I don't see big difference
Actually faster shift in 2-3 shifter not accelerates 2-3 clutch shift
It lowering reaction time when solenoids took a command from PCM and real shift occurs and helps not overrev engine due to lag between command and real shift
In another 4st tranny that I build a lot of times when I increase 3rd feed about 250% from stock at medium throttle I achieve drop reaction time from about 1 sec to 0.3 sec and it looks like instant shift
But I made zero tune to AFL and solenoids
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Your mod with spring to 2-3 shifter simply changed ratios of force applied to it and force of spring can put shifter in unstable position if AFL pressure drops due to wear or if spring is too tight - because spring force not linear
OEM method with 2 unequal areas will work no matter of AFL pressures and to increase speed of 2-3 shifter we need to drop pressure faster(and restore opposite area volume of oil fast) that means bigger orifice in solenoid(and no restrictions from AFL feed to the tip of 2-3 shifter)

 

All I know is with my 2-3 spring mod with the dyno and multiple customer test even of just dropping it in the WOT command to actual shift wa shortened significantly and it not a new mod i first did it over a decade ago and has been in 1000s of units literally wth 0 issues. One recent person just got the valve and dropped it into his bone stock truck and went from ,300 shift time to .125 at WOT . He got it as he wanted to see how it would work as a stand alone mod. Vehicle had 70k miles he told me.

 

I googled AFL pressure and google says it can be 55 -110 PSI
I measured dia of 2-3 shifter and shuttle that works with AFL pressure and looks like GM took very safe difference in dia to achieve good force
Difference in area more than 2 (0.3937 VS 0.5984 dia)
Force from solenoid is about 8-16lbs
I need kinda sturdy spring to lower that ratio in force

 

The spring I use is pretty sturdy. Not 1-2 valve sturdy, but sturdy enough. I have not played with sturdier only because I worry that at LOW AFL like coast down 3-2 it might slow it to much. And at present i dont have a dyno nor the time to do test with my own car . So I just stay with what I already know works for now. In my initial test I did use a weaker spring and on the dyno it made no decernable difference. But the one I ended up with was qiuet notable even just observationally. Particulary at HIGH LINE WOT shifts.
I basically look at it as a little helper.

 

I saw good video on YT about 8L series
Interesting fact -8L has independent source of low pressure to fill all pistons and apply lines full of oil
And they don't afraid of centrifugal apply -looks like they used very sturdy spring
It makes sense cuz with all lines filled they have zero lag to clutch apply

 

Just a note, While I have had the jig and been doing the OVERSIZED AFL on the 4L60E as needed and the gently oversized as standard. Increasingly as with the two VB I am working with now one a 95 the other a 2005 the bores are just so badly erroded that even the Gently oversized is leaking when i test much of the time. So I have decided and ordered acordingly to just start doing the reaming replace with oversized on all units . The time it takes to replace then test with the gently oversized is just not worth the money saved on the build. Dont get me wrong the GO valve is great for the novice or someone who sparingly builds these and suggested. But for me not worth the savings as I have the tool . JUST AN FYI . I am using the transgo version as the valves and gig is much more reasonably priced and avalabilty of valves more consistent.

 

I have covered this before. But when using flat bottom 4th servo like sonnax or superior , Band clearance must be pretty close as you only have a little over 15/64 travel possible till it collides with the second servo and you will have issues with slipping or no 4th. the sonnax can be tricky and actually give you a more prolonged 4th failure as the small center servo can travel further causing a much small servo area to apply the band , As the inner can travel further than the outter.
And of course if you use the SUPERIOR second servo it must be machined to work with these,
The stock 4th servo does not have this issue.

 

Hi again
Line to lube mod
Grind further PR valve to make notches bigger or drill wall to add another passage
What to choose ?

 

Nothing, the flat they come with and have since the late 80s is plenty IMO. Pull a line off running you will see more than plenty but far.

 

SOMETHING I HAVE DISCOVERED THAT TO ME IS TROUBLESOME.
In the past I have used SUPERGLUE FAST HARDENING GEL as a shaft to drum sealant / retainer, This has worked well for years and I know it worked as I have tried to press shafts back out after a day or two and literally ripped aluminum bits out with it.

However after seeing many using the green locktite 620 lock and sealant instead , I started using it instead because I supposed it would have a little slower drying time, Using the super glue you must move quicky else it can literally dry as you are pressing shaft in and try and stop the proceedure.

Well I have used the GREEN a number of times but realizing with the slower dry time air checking imediatly could not be done. But have seen no actual issues.

BUT I had pressed a shaft in with it a couple months ago but then found an issue with the drum so i sat it on my shelf and used another and marked it.

Long story SHORT- I needed the shaft out of it this week, So I placed in press and it came out pretty easy really which suprised me, But then an alarming discovery . The green is still liquid with only the slightest gell like hardening, This after sitting a month !

Now if I am using the wrong stuff please let me know but if I am so are many others, But if not THIS WILL NOT WORK AND IS AS USELESS AS NOTHING!

If it requires heat to seal harden BIG PROBLEM! Whatever is used MUST CURE at room temp in the presence of AIR! (I guess you could take a torch to it to harden)

Why? Because besides retention that is the whole purpose to not only retain but seal. if it remains liquid in presence of air then its useless as the first time the car is started and line presure hits out it will go . So would be usedlless for retention or sealing in such a condition .
So at least in my case I will be returning to the super glue quick drying gell unless someone can show me a proven or at least something I can prove works as well.

INFO RANT OVER . Opinions welcome , I realize the "superglue gel fast" may seem un-orhodox But for me at least it has proven to work even though a pain having to be in such a hurry to get applied and shaft installed and holes blown out before it hardens to much.

 

Green Locktite 620 is what I have been using. Your findings don't sound very encouraging. I use the 620 on pump bushing and any other big sleeve/bushing.

 

anaerobic compound it cures in absense of free oxygen , So probably fine for a bushing , Seeve but as a sealer for a drum which may actually have some leaks aka air. I would say its pointless.
The spines are certainly not air tight, the shaft to drum probably is if BRAND NEW, But assuming the idea is to use it as a sealer retainer in a conditon where air may be available like a used drum. i no longer think it would be a good choice.
instead an aerobic sealer which in my case would be superglue gel quicksetting would be more suitable. And in reality which i will be thinking on a two part epoxy which required neither state might be a better solutions.
Going to be doing some test with various stuff. I know the SGG after even a day used in/ on the shaft splines and shaft is solid and will rip aluminum out with the shaft if you try and remove it . The only catch with it is from application to finish install you have less than 5 minutes.

 

Interesting. I used Locktite 620 successfully with no issues. Wondering how many drums that were sealed with Locktite 620 failed over time.

 

In a perfect world it would make little or no difference either way, As the interference fit of the drum/shaft would seal. But we are talking 100k 200k units, Now while the shaft may fit tight still erosion as with the VB end caps is a consideration. As over time small expected leaks would do this. But in the real worlld 2 choices exist here , Replace drum with new $500 min as far as I can tell if you can get hold of one from GM. Remans but they are nothing more than drums cleaned inspeacted and it seems same sealer used.Or get a good used that does not leak (yet).
The sealer is more about insurance than anything. And from what I can tell the green 620 WOULD not be good insurance unless the drum was perfect to start with. locktite red has same issue. does not harden when air present or O2 anyway.
Me I air test the drum before disasembly , Then wash, Then heat drum and remove shaft, The I used to clean and then put the SGG on splines and a thing coat in shaft area which indeed works well and the fact that it does require O2 to harden and did harden shows air indeed was present along shaft and in splines.
So really it is down to ideally .
1-REPLACE DRUM AND SHAFT REALLY AS EITHER OR BOTH ARE PRONE TO EROSION OVER TIME.

2-REMOVE SHAFT VISUALLY CHECK SHAFT AND DRUM FOR SERIOUS WEAR EROSSION - IF NOTHING OBVIOUS USE A SEALER/RETAINER THAT WILL CURE IN THE PRESENCE OF OXYGEN .

But honestly then unless its a GM drum which are always on backorder even for sonnax who needs them for the smart drum or some aftermarket with unknown origin or quality.

So IMO realistically the green is useless and it cant actually seal a even mildly leaking drum and will not harden with air present and once fluild applies just get pushed out via any leakage .

So as I mentioned short of a NEW drum at 300 to as much as 1000 for every unit , The best move is some air cured or two part expoxy type sealer. needs to be high temp and for most shops cured fully in less than 24 hours .

 

Frank, what is this SGG glue and where I can get it?