Today I spent several hours to trace every fluid passage at VB
And I think I must correct you -OR mod not used FWD oil - you connect overrun bathtub to D4 oil gallery
I checked it at least 3 times
Why I recheck already done mod ? I want to figure out how to use FWD accum to overrun oil if I get rid of FWD oil at all and use whole FWD as overrun clutch - so I need soften a bit its engagement
And looks like if I unite FWD and OR oil inside stator (like not to install teflon ring or so) - I can use FWD accum if I completely block FWD orifice and checkball and also use some spacer instead of spring behind FWD abuse valve
I also reinstall FWD clutch without OR clutch and found that custom FWD piston will allow me to enlarge FWD pack to 9 disks (or less if I wanna use less -higher piston will solve this)
With such OR clutch I think I definitely need accumulator to soften its grip but im little aware will fwd accum works good with such long path
And I decided to make reinforcement sleeve to both FWD and OR input drum areas if I need custom piston for OR clutch
Inly one question not answered yet - how to make inner wheel to 9 disks
I think I will weld 2 FWD inner wheels together and make custom sleeve instead of one way sprag
Yes it will be heavy - but right now I dont see another option (I dont wanna order custom parts from machinery shop - it will be very expensive)

 

Yes, and Forward oil is created by/ fed by D4 oil.

In these very basic Hydraulic Line Diagrams there is little to no point in differentiating the two different Fluid Names for a situation where the only components originally being fed pertain to starting forward momentum (I.E. to apply the Forward Clutch and prepare the 1st Scheduled Shift Valve-Train).

Once said Fluid passes through the 1-2 Shift Valve-Train, I see the point in distinguishing it.

When we start breaking down the Hydraulic Circuits by Orifice Name and Number to distinguish Sub-Circuits, or Circuit Branches that divide for individualized specific functions; then sure Knit-Pick a little bit.

 

Man c'mon
D4 is full flow that can be produced by oil pump and all forward gears supplied by D4 not only FWD
Frank says OR mod robbing FWD oil but FWD oil zone behind FWD orifice and OR mod not affect directly to FWD because its oil taken before any restrictors
Actually if oil flow enough to achieve desired pressure -nobody robbed

 

And I forgot about OR clutch pack that his upper disk is FWD first disk and when OR piston engaged it not lowering force of FWD piston cuz OR piston just push thru because lastOR/first FWD has no snap ring and cant push against fwd
My bad - I used to work with jatco and it has snap ring
Actually without sonnax reinforcement sleeve OEM OR piston took some area of drum at inner dia and slightly increase force to FWD clutch - not significant but increase

 

Yes the OR mod is fed from D4 Oil before it becomes fwd oil , I was never concerned with a leak or excessive oil via the OVERUN mod as when it dumped the fwd clutch in 4th is doing nothing anyway, But so be if I used wrong terminlogy d4 vs fwd oil later, My voiced concerned over taking away from the FWD clutch has to do with the Band cooling mod which most certainly is coming from the FWD feed and making those to large.
However I do still have concerns of a HUGE D4 leak prior to the FWD circuit which is why I cut gasket rather than make large feed of some sort, Call it D4 fine but would still be a huge dump of main line IMO done that way,
I stick with my small slot created by cutting gasket which has proven for many years to be more than adequte,
Regardlelss of oil take off point I am always consceinous and concerned with excessive leaks where not nessesary .
I go to great effforts all through this unit to seal up every posssible leak. Certainly not going to create otthers unnessesarily and to excess.
Ultimately the D4 oil is feeding all including the 3-4 and od servo. So a large leak here you might get with a large feed to the overun mod when the valve dumps it in 4th would stil not be a very good idea .

 

I agree that making band cooling orifices should not be big(because at some point more oil not increase cooling but wasted) -but I think FWD abuse make so big passage to flow from D4 to FWD that its not the problem
_______________________
Its GM called not me and D4=main line
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Its not a leak since OR not leaking itself -just another clutch to operate
And it not going full flow if you leave checkball there it belongs to OR - OR orifice smaller than your passage in gasket
I also not see a reason to engage OR slow - its like releasing clutch slowly in manual tranny in hope that it will help maintain engine rpm -in result slowing engagement just burn tiny clutches
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I calculated piston area and standard FWD piston generate 3800 LBS at 230psi while 3-4 only 2000lbs
difference is huge
And we talked above about FI drum that have +25% of piston area
If I increase pressure to reverse numbers (280+) I achieve exact same +25%
And for not braking FWD I should lower FWD (and OR) to same 25% of area
Standard servo 553 becomes a corvette+ servo - and 4th servo will be like sonnax dual
I see no drawbacks -only increased load to pump

 

When I mention leak . Its not another clutch, The 4-3 VALVE train literally dumps the oil in the OVERUN circuit into the pan when 4th enages , That is how the overun is released on the 3-4 shift . As for buring the 2 small clutchs I have been doing this mod for over 10 years and been back into units with the mod and 50k plus miles and never seen any sign of burning. The OR clutch mod is not intended nor does it replace the Sprag . But rather helps to lesson impacts to the sprag and help support and also prevents coast wind ups from hitting it so hard. Its more a helper than a holder and prior to that mod rolled sprags in HIGH HP and or very heavy vehicles was the second most common failure we used to see (3-4 always being most likley ) . Once Instituted the OR MOD we never saw another rolled sprag again serioulsy even with 1000 plus RWHP TRUCKS.
I have played with the shifter in my own car bearing in mind with the OR mod no other apply circuit works and pulling down from 4th d4 to d3 the braking is instant al low coast presures. Bear in mind the circuit is never OFF its charged and full, Just being dumped . The Instant you close that dump the OR is on.. Now as for making feed to it larger that is fine but when i never tested that I have tested this by accident a few times over the years, The 3-4 APPLY PISTON omited accidentally by the builder this being fed with a .093 hole and on main line it was very obviousl as beside having no 3rd it dropped 20 lbs of main line on the dyno the second 3rd was commanded.

Now on the 280 psi in 3rd, You are welcome to try it , I can tell you I once had a unit with a stuck slide in pump (the slide actually acts as apart of the regulation circuit ) It was stuck because the pump was freshlly machned leak free but the slide to thick. But it caused 300 psi when it was engaged into D4 and then shiftet to 3rd gears a bunch of noise started , On tear down both the FWD and 3-4 snap rings lugs were broken out of the drum so IDK .
The other issue I see is getting the range several things would come into play /
1-I would have to check but I think the releif valve/ball in pump releases at about 300 psi .
2-The slide I think would move to small pump against the spring. I guess a stiffer spring? I know blocking at least with a non leaking pump the regulator valve itself cannot dump enough to regulate at higher RPM.
3-Range to get 280 unless using something like i mentoned and feeding oil from the 3-4 circuit in some metered to rev boost part of boost valve I dont see a way to get a range of less than 100 to a max of 280 which you would not want more than 100 on the PRND shift into gear . Would be very uncomfortable I would think. I suppose you could try and tune the range in with the PCS current if it could give enough. But you would need a pretty stiff PR spring and its questionable wither you could get a range from less than 100 at idle to 280 at wot . But maybe possible?
4- You have mentioned using both parts the boost valve earlier. I chose the idea of the rev cause its not in use in FWD gears, The otther part is being fed AFL oil to vary line if you introduced more presure to that cicuit it would charge the AFL which can cause other issues. I Have seen and helped people who had the line turned way up in tune (high afl) being unable to make WOT 1-2 and 2-3 SHIFTS and even one time helpd a guy who the trans worked perfectly drivng arround and great even at heavy part throttle . But at WOT he though he was neutraling but in reality we saw on guage he was making 270 psi at WOT and with the particular PR set up he had (Mine with the little spring and .500 boost valve)That should not have been possible. So the AFL was way high. This we traced to a combo of him having the presure table at 99 but had to reduce to 80 to get the shifts (Way to much) So we changed the PCS and then set back at 96 and all was good. So he has two issues the setting was to high and the calibration of he PCS way off . But what was happening the AFL was so high at WOT it would flood the 1-2 and 2-3 solenoids and force both valves to 1st gear positon which at the high speeds felt of course like neutrat and of course at WOT he could not shift 1-2 . Just some notes for you. So IMO to get that 280 at WOT you will need some other method of boosting the line on the 2-3 shifts besides tuning or super stiff PR springs to get that such as the idea I had of feeding the rev boost with metered oil with some sort of check valve system. Maybe as simple as blocking the small hole in the REV feed and placing a ball on the otthe side and then feeding a metered one way oil to the circuit from the 3-4 though if the metered was small enough a back leak might not be an issue as the circuit would be dumping when in actual reverse.

Ok My thoughs for whatever they are worth. Not here to argue just exchange ideas and information/experince .

 

Disagree

OR feed closed (where we make passage and now its under pressure with OR orifice still ON if flow be fast enough to lift checkball)
Dumped into pan only clutch oil from drum
I see no problem here
When 4th commanded - feed closed

OR line from 4-3 sequence to input drum has a checkball into oil pump case thet stays open without pressure
And because of difference in height -you literally have pipe with 2 ends open (checkball and 4-3seq) that can and will be drained at this sector
And OR piston itself with feed line inside drum also will be dumped at 4th
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I see no problem with oil pump too because when you engage REV -pump give you 300 PSI at WOT with same internal components
There is no problem with pump -it give you as much as you want
The only drawback -increased load to pump splines
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Yep -when you engage REV -both areas of boost valve being fed
Rear part by AFL pressure and front by full line pressure
If we block front part from taking oil from REV oil (full line here) and redirect torque sig oil to both areas it will drop REV pressure but increase front pressure
With increasing AFL and using 0.500 boost I think it can be tuned to 280 PSI or more
High AFL cause problems when its too high and solenoids cant handle it
In stock settings we have about 60-70 PSI with no torque signal (PCS drops all feed to pan) and about 180 PSI at full torque sig (PCS closed and all AFL pressure goes to boost valve) -GM says its 90PSI (90 and 96 PSI in tables has equal amperage to PCS -you can see it in table above)
With increased boost valve we simply change ratio of amplifying torque sig pressure to line pressure
Stock boost valve = 90TQ to 180Line means 1:2
Sonnax or transgo give us about 230 so its close to 1:2.5
With added REV zone at boost valve it will increase more -dunno how much -will measure boost and calculate later
But lets pretend it will be 2.7
To achieve 270 PSI we need 100PSI at AFL
Not so big increase I think
I saw suggestion here to use 3-2 spring inside AFL spring to enlarge pressure - maybe with such mod AFL pressure already over 100 PSI )
And about affecting line pressure to AFL pressure -its cant be happen
AFL is pressure regulator that control itself by closing its feed when pressure is enough
Increasing input pressure has no affect to output AFL pressure
The only thing can happen -in will oscillates more - but it can be harnessed by adding notches to let line pressure not bumping inside (I saw such design at more new trannys)

 

You have to take in to consideration that the wear and tear between components, as well as less than ideal tolerances of mass produced components will leak fluid to an unwanted extent.

And no, I am not going to debate any of my posts... I am simply sharing my experiences.

 

It has been sometime since I set out to do the OR MOD so may have forgotten it blocked but knew it dumped ,My oversite there.

Still not sure what you mean on AFL if you feed it line in the solenoid side I still think it would be unable to regulate of course you are now venturing into areas I was never afforded to venture into as I had no means to test unless it was something I already knew for sure would work.
I do know that while I have not had the issue with my own car as i have worked with people doing tech support where we reduced AFL in tune to get a shift that would not happen at 99 percent but they noted a slight ever so slight let off of the pedal and boom it shifted, We lowered the AFL in tune and sure enough it shifted just fine. My logical assumption but no means to prove was and is that the solenoids capacity to dump AFL was exceeded and of course the one particular case I mentioned with the unit dropping to 1st at wot even though it was not commanded feeling like neutral .

Maybe I am missunderstanding but if you feed from the BOOST valve side would that not be the AFL circuit unless you blocked it from backfeeding somehow ? I am not sure the AFL VALVE could compensate unless feed was restricted ?

But again at this point you are venturing into areas while interesting are outside what I have the time or way/ means to test .

Also please bear in mind i have at present only one way to test things MY CAR as I would not send something out without a thourgh test on a dyno or in a car as i have a number of times with new mods run into unexpected side effects.

So any mods I make i do 2 things, I make sure they are full proof before doing them and 2 are easily reversable both for me in testing and if it were to come to it on the customers end if they really didnt like it (OR MOD FOR EXAMPLE JUST CHANGE PLATE OR REPLACE GASKET AND REINSTALL ***** ) Though rare it has happened a couple times the customer just really really didnt like the feel .

So minus a Dyno to test and not willing nor having the time in my own car i will leave these type mods to you lol.
Perhaps you should make a thread about just these new mods and how they turn out for you . i WOULD certainly follow and comment give feedback.

As for me all the mods I list here are long tried and true as I dont want to ever make someone more issues .

I do truely wish I did have a shop with a dyno or even a lift and or a test car to do a number of ideas , Such as I can make the LR clutch come on in auto functions and for really HP cars and snow plows this can be a low roller savior , But from doing it I have noted that the 2-1 is very agressive on coast down So I only do it rarely in very specific cases with a long explanation of the unconfortable feel it may have,
Someone suggested shrinking the fwd feed and blocking and using the fwd accum to make this more livable. AND its a great Idea, But again at this point I have no means to test that except my own car and I well actually need it lol.

The ideas you have are promising but not stuff i perosnally have the time or equipment to do .

I do however still worry alot about the input drum at over 250 psi in one of the mods you suggest, When I mentoned the bleed block to the rev i was not thnking line but rather a small metered bleed to raise the line in 3rd abd 4th only by 20 to 30 psi at all throttle progressively following the main line rise curve and limiting it with an orifice taking what i normally see with my boost and small spring 210 to 220 max to 240-250 max .

But as you progress keep us posted will be interested in your results .

One other thing while Im here I worry about at 280 or more PSi is the dish bow of the apply and back plates allready an issue . Seems this would be compounded further which can be compensated with thicker of each but at a cost of number of frictions ? I do however suppose thinner plates of some other much harder steel could be made That would not flex bow ?

But again unlike you it appears I do not have the available time or means to test well and then introduce . So I just stay with stuff I have allready come up with or someone else has tested I am always open to others ideas .

 

I see some misunderstanding here
AFL is pressure regulator that drop line pressure to acceptable limit to all solenoids
It cant be changed by tuning -only hardware mod (stiffer spring) can rise/lower it (and wear of course affect )
Torque sig is pressure behind PCS solenoid and PCS solenoid at MAX just connect AFL to Torque sig without restrictions
From table of PCS amperage we know that torque sig can change from 0 (PSC closed) to 96PSI (fully open)
It means that GM adjust AFL to 96PSI desired
So if we change actual AFL -we drift all line pressure and PCM dont know about it
Boost valve at FWD gears is mechanical(hyd) amlifier
When it took max TQ SIG (96PSI) -it pushes reg shifter with max force and in result we achieve 180-190 PSI -in means that AFL to Line is 1:2 ratio
I just want to change it to achieve REV like pressire at FWD
And to not damage input drum I wanna change custom piston to FWD with smaller area to lower force to FWD snap ring
So
I wanna understand to myself will be get rid of FWD and make OR working with FWD clutch not so rude to 3-4 and 4-3 shifting cuz now I still have OEM config with sprag and I cant feel is OR release in time when shift to 4th or I achieve flare
This is the only thing bothering me
Cuz I believe that FI drum with wider piston that provides +25% of clamping force will load snap ring the same as standard OEM drum with +25% pressure
So I need only to drop pressure for FWD (and OR) to leave force in acceptable limit by shrinking piston dia (and as a benefit use this space to thick reinforcement sleeve to input shaft)

 

Measured today stock boost and sonnax 0.490 (dont have 0.500 right now)
Stock is 0.420 and 0.465 rev
Sonnax 0.486 and 0.52756
If I will use that rev dia it will allow me achieve 280 PSI at max and still 60 PSI at min in forward and reverse -which not good cuz stock pressure for rev at idle is 90+
And there Frank spring mod can and will rise start pressure from 60 to ... depends on spring of course
I dunno where is rev pressure inside firmware but if adjust it to start not from 0 -no spring mod needed

 

Hello Frank and All!! Been following this thread for a while and would like to give my input on the 4, 5, and 6 pinion gear sets mentioned earlier.

Scanning the material content for both a 4 pinion front and 5 pinion front I get what appears to be C1020-C1026 classification for both units with some small traces of Mo Ni, Cr, Al, and slightly different mix for the 4 pinion name "41", and name "51" is the 5 pinion material content. I did NOT scan rear planets, Sonnax 6 or aftermarket units. If there is a metallurgist in the group I would be curious on a more expert opinion, but from google:

C1020

One of the most common carbon steel grade. C1020 is a low tensile carbon steel with excellent machinability. Commonly used for DOM processed tubing. Similar to C1026, both are iron alloys and have close composition.
From my perspective the material used to make either set is nearly the same. I did notice that the 5 pinion front appears to be a 2pc unit, where as the 4 pinion looks like a complete casting.

Front planetary:
I have not had any direct failures from either the OEM 4 or 5 pinion units here. I think its obvious that the 5 pinion spreads the load and the support towers between each gear appears to be thicker. I didn't catch a weight difference but the 5 pinion is noticeably heavier. In any performance application I would accept the 4 pinion or a true OEM 5 pinion.
6-Pinion Sonnax: I have 2 of these in my own turbo vehicles and a few others in customers. I would not push for this gear ratio change for NA cars or vehicles under 500HP, you will suffer some 60ft time as I have with mine. Now, in the event where we are making 700+ with a Rossler transbrake, we were able to control the wheelie in that specific car netting better times at the track due to keeping the car down. The slight rpm drop can be viewed as reduced shock between gears, but this is minimal. Overall, very good upgrade when big power is being made and the OEM 1st gear become tool low or a ratio relative to power being made.

Rear Planetary
Although I do believe the 4 pinion is good, but I also see those wearing out pinion bearings on higher mileage units more often. To be fair, the 4 pinion is also more common so a true wear comparison may be hard to determine. With the 5 pinion the amount of load each bearing set sees is reduced. Every single planetary failure I have seen can be tied back to another failure. the rear 4 pinion unit I split years ago was the results of a rolled sprag catching and grabbing. It shocked and split both the reaction hub and rear planetary. The 5 pinion set pictured that's broken was from a rear axle locking up, shattering the low roller, and taking the planet with it. As for the aftermarket non oem planets, I have one pictured I got from PATC and they ensured they were quality rebuilt units. Still makes me nervous but its still in a 10 sec car today.

To sum it up.
I agree the 4 pinions are plenty strong if in good condition. If I were to upgrade I would do the rear 5 pinion first and be ok leaving the OEM 4 front pinion unless I got a good deal on both sets. the Sonnax 6 pinion is nice, but mainly for high HP units that can pull the taller gears or need wheelie control. Thanks Frank for opening this thread and I hope this was info we we all looking for.



Had the opportunity to scan the material type for both 4 and 5 pinion OEM sets. It was mentioned that the 5 pinions are made from inferior materials and it was questioned if they even offer a benefit when installed.

 

Great information IMO I use 5 pin in my stage 3 and max only because its expected , But would have no fear with 4. And yes I agree on the sonnax , Much like people who switch to the 80s many are disapointed at launch once the change is made unless very high power. I have never driven a car with them, But have installed a few at customer request. Feed back has varied. But for the cost IMO not really worth it .

 

Today I decided to compare FWD sprags between 4l60 and re4r03/jr403
And I feel sorry about GM because both was developed by GM engineers
Re4 has no issues with sprag even beyond 1000Nm of torque
As far as I know they develop re4 after 4l60

 

V8Fan,

I share your thoughts with the 4L60e Sprag. I think it is a bit small and has areas to be desired for improvement. The "HD" 60E sprag is the biggest "widest" I have found, and has held some decent power in my builds but the brass continues to be a quick wear item vs the BW unit. For the very popular BW unit, I have rolled a few under abuse. As you may know Sonnax and Frank even has a few mods to support the sprag in higher tq applications, but the downsides to shift comfort and overrun hub load will always be present.

For mine, I use the HD sprag when Budget allows, Sonnax HD 2-3 shift valve, and customer education for drag racing in D3 will allow this area to become more of a non concern. Or in many cases a New HD unit I leave overrun alone in sub 500hp units.

To this date I have not seen exploded inner nor outer races. I'm actually surprised the aftermarket has not adapted an even wider sprag with steel retainers. If BW could duplicate the GM HD sprag, maybe even wider with their steels cages/retainers, I think that would go a long way.

Lets lay we never had a sprag issue, then we wouldn't have to do any overrun/2-3 valve modifications allowing the transmission to upshift/downshift as intended. remember, when the overrun is applied, you risk bind on the 2-3 shift. Timing becomes very critical.


As shown below you can see the width difference from the common SK, the aftermarket BW, and the later model HD GM unit.

SK(common in all Stock 60E units) .416 wide
BW (Borg Warner "Aftermarket Upgrade") .410 wide
HD (GM Late Model unit, dual gage, but one is plastic) .457 wide.

 

I found myself that overrun mod actually has some benefits in daily driving
It allows to brake by engine in slow driving
It 'race ready' if you wanna floor it without preparation like put in D3
And bumps in 4-3 and 3-2 noticeable but not so bad
But Im thinking if I get rid of fwd sprag and make both OR and FWD clutches work as OR clutch - bumps definitely be harder because of much bigger clutch area
So Im in doubts -should I make such experiment or it will be undriveable as daily driving
Im not afraid to make it and modify parts -Im just lazy to tear down it again if I dont like it cuz I have AWD and it adds time to drop tranny

 

With few exception many including myself actually like the OR mod as the car feels IDK more solid and seems to hit harder coming back in. The downshift is just something you soon ignore and on most cars its barlely notable if the tune and all is right and idle not crazy high.
No run into any bindup issues or anything with the mod, In my own car I will say even if someday I buld its trans again and even if a stronger sprag exist by then. I would keep the OR mod as I feel keeping everything moving together as it does helps in more ways than just the sprag. Also in a decade I have not seen a single year down where the OR clutch showed any signs of burning with it,

 

I'm unsure how you will eliminate the forward sprag without sacrificing 4th OD gear. From my understanding that's where the overrun clutches can no longer be applied and the sprag needs to spin freely in its unlocked direction. No I suppose you could weld sprag solid, apply OR and FW clutches, sacrifice OD, but then you'll just have a electronically driven 3 speed. Or did I misunderstand your goal?

 

I think you skipped our discussion with Frank above ))
After 4-3 sequence shifter goes to 4th gear position it drained oil from OR clutch pack and FWD sprag starts to rotating as it should at 4th
But lets pretend we not have fwd sprag and clutch at all
With OR mod we have 1-2-3 with overrun CL that connected between input drum and sun gear of forward planet same as before FWD sprag and clutch did
And OR just goes off at 4th by 4-3 sequence and kicks in when 4-3 shifting occurs
And because we dont have fwd sprag any mismatch between OR clutch and 2-4 band can result in binding (real binding cuz 3-4 CL + 2-4 band = 4th gear but OR will work in that situation as transbrake) or flare
4-3 looks like will be no big issue cuz now with OR mod I dont feel binding (but increase from 2 to 9 clutches definitely will change feelings) -but I dont know what 3-4 shifts will be without FWD
So I start to self educate myself about ford 4r70 to understand how it works in it