Yes i know, The primary thing I have seen with it to tight its literally cracking breaking out rear of case , not damaging bearings or thrust washers.

 

You forget that output shaft also extends in length with same rate as all parts on it
Im chasing decrease shell side play to eliminate potential hit between shell and input drum if I make custom cap with tread that enlarge input dia
And also decrease end play to lower max side speed of components when they hit bearings
If manufacturer says 0.005 enough - I wanna set it close to 0.005
I machined today reaction shaft that was for washer to accommodate 2001+ bearing between shell and it and achieve 0.006 end play at output
Shell almost has no leaning and whole assy rotates freely but without excessive movements -looks solid to me
Now I wanna machine brass bushing to input shaft that will support output shaft(as FRANK suggested) -I think it also helps to decrease vibration and lowering output shaft bushing wear
Currently Im driving my second tranny where I also set output shaft close to 0.01 (by adding bearing and machining ) with overall endplay(input shaft end play) 0.013
And it shifts at WOT like CVT without any harshness that I even start thinking to add that 2-3 spring to increase 2-3 speed
Maybe use 3-2 as 2-3 also helps too
I definitely feel overrun mod work at braking but my 6sp tranny make same jerking with downshifting at light braking so I'm kinda prepared for it

 

Many of the Factory Tolerances and Clearances were very far from ideal.
So we do not follow them.
Through lots of R&D, Testing, Trials and Experimentation, we found what works very well for us.


Not all of the Torrington Bearings in the Transmission serve as a Thrust Washer that contributes to the "stack-up" that will determine the amount of end-play.

When calculating your desired end-play, only include the Torrington Bearings in the stack-up.

Many Builders have different opinions on this, however I agree with and follow my Father's opinion on this matter.
He prefers that there be 0.001" clearance for oil-film, for each side of the Bearing, for each Bearing.
So if there is 4 Bearings in the stack-up, that is 0.008".

Many builders will run far less clearance/ end-play for that scenario; however my Father found that the Bearing and corresponding Components last far longer with the Bear clearance that He chose.

Many builders make their way work just fine, But I really like the 0.001" clearance for Oil, much better!


-Chello III

 

If we use Torrington as journal bearings of the engine )
Oil film in the journals is about 0.0003 to 0.0006 -lets choose 0.0005
So to both sides it will be 0.001 )
But ball bearings turbo teach us to avoid bearings flooding with oil because bearings must not slide at oil like journal bearings or it will damage em
As far as I know about bearings if their load not above limits and oil is enough -they 're fine
But if we use engine oil film thickness as a starting point to calculation
0.001 per bearing (whole -not one side) x 4 bearings of output stack = 0.004 and + input shaft (3 bearings) =0.007
I achieved 0.006 to output shaft assy and it has 4 bearing that involved in stuck end play (5th that captured in rear planet avoided by sonnax smartshell)
I think its more than enough
With total(input) end play close to 0.008- 0.01 they will be fine (especially when case will enlarge in length faster with heat cause its aluminum)

 

You are comparing:
-a Ball Bearing Assembly that is fed engine oil pressure through a restrictor orifice in the turbocharger oil feed inlet.
TO:
-a Torrington Bearing Assembly that is not fed any pressurized oil supply, but is splash lubricated.

These are two very different situations in terms of oil flow and pressure, not to mention the intended type of forces acted upon these bearings.

I thank you for sharing your opinion, but I will stick to what many years of accumulated data from R&D via real world testing.

 

who you trying to convince? Me? Yourself? You are free to do what you want. Also free to think what you want, but in reality your theory that the output shaft grows too has literally zero to do with the actual result you will encounter from too little clearance. I, myself do not wish to take chances on customer units for the sake of experimentation. Especially when I have nothing to gain and a lot to lose. I don’t have problems now and i won’t chance having them, in an effort to fix a nonexistent problem. I won’t try it on my own units either because I don’t feel like pulling it back out if it fails. Hell, my personal unit is behind a 800+hp turbocharged built 5.3 and it’s been together for about 5 years now and over 60k hard miles. I’ll stick to what I know works. I urge anyone else reading this to not set up endplay any tighter than recommended in the service manuals unless you are trying to experiment and are ok with taking a chance for having problems and destroying parts.

tighter clearance will probably be ok under normal operating conditions and temperature. However, consider that someone is pulling a trailer on hot summer day and the temps of the fluid are elevated. If stuff starts biding due to lack of growing room then guess what, more heat happens. And the longer it’s driven, it’ll get worse until it locks up. I know this from experience. As much as I hate to admit it, years ago I sent a unit out with around .005 on the output. I didn’t think much of it because I thought the end with the aluminum drum was much more critical. Well about a year later it came back with the output side and melted and welded together. That’s why I’m warning you, but seems like you must know something I don’t, so have at it. lol. 😂

my suspicion is the clearance recommended is based on all conditions. If your trans runs 150f degrees under all conditions, you’ll likely be ok. I’d rather have the safety cushion of the proper clearance. There’s already enough to worry about with this trans, I’d rather not add another thing to worry with.

 

Cant say I DISAGREE. If I was gonna err on these units on endplay it would be to the high side. I have seen the results of too tights, melted thrust washers and even the back of case broken out. Hell I even remember when the sonnax guy came to the shop when I built the first Black Edition years ago, We got to endplay and I went to check it he grabbed it the shaft , pulled it in and out and said "YOU HAVE SOME" and well that seemed to be the limit of his concern and being he was one of Sonnax top techs that told me alot. That said I try and make sure it is someplace inside the spec and do not see it as a big deal otherwise. I have never seen a failure due to to much end play but have seen several over too little.
I am very particular on builds and fact is some things REALLY MATTER other not so much. To me the biggest thing and the most important thing is FIX THE LEAKS and this is where most of my efforts go .
I dare say do that, replace the sprag. do overun mod, use whatever frictions you prefer, make sure drums and plates are flat . Use whatever servo you like or that suits your goals , a good sunshell late stock, beast or sonnax, Size the feeds adequate for your goals not insanely large and you have a solid 500hp unit.
Beyond that just a good rebuild making sure bushings and such are good and you got it whipped.
I do create new mods but they are never to redesign the unit as I dont have the means for that type experimentation and testing. My mods are alway to compliment or reinforce what is already here not re-design the wheel as I do not nor ever have had the means or the time allotted to do so and certainly do not as of now.
Now in the case of V8FAN if he has the time, money and is trying stuff on his own car or has a DYNO awesome for him . I wish I had or ever had the same. I know I spend weeks studying the Overun mod I wanted to do before I ever even incorporated it into a unit and started playing with it on the dyno I had access too as simple as it is and the first few methods I came up with I deemed to risky before the final one I use now and have for many years.
I would never suggest an unproven or at least untested idea in a public forum. I will discuss possible things when people bring them up. Or in some cases even explain why they might be a bad idea, usually from experience. Even when I published my Overun mod method here I explain the 3-2 bump downside so it can be expected as for some it is indeed a major turn off . though I rather like the feel and use it on all units but explain the feel to every customer.
The min spec on these GM assumed a host of scenarios extreme ones at that and temp changes and variations as they never know what circumstance the unit may have to live in 250f on a hot day in heavy traffic in TX or 75f below in alaska So IMO the GM PUBLISHED absolute min clearance here should always be observed and never less than and because as we all know the steel and aluminum parts along with Bushing and more even from GM are made of somewhat different materials depending on where they were sourced by GM much less aftermarket parts knowing the exact expansion rate is in reality impossible to know without testing each and every part individually. But we do know they "should " be without the range of the GM specifications so you are safe in that range.

 

A new suggestion for units
After much testing at various temperatures I have determined a simple test for leaks at the in drum shaft area is impossible at simple room temp / I have tested a number of drums at room temp and even at 200 psi tested solid. Placed them on oven at 200f so they would heat even only to find they the leaked like a siff More often than not. So It is my determination that it is necessary to properly remove the shaft from the drums (IMO preferably using the method I have written of earlier in this thread) Inspect drum and shaft, Reseal with seal retainer compound and press cool shaft back into warm drum. Note this sealer takes 72 hours to cure at room temps 75f or some quicker with warmer temps. You can get the specs for this on the makers site.
But for sometime now I have been doing this with every unit and suggest for all.
I even went as far as grooving one shaft for a small oring between each section of the shaft which I think is a great idea. But for now at least have not incorporated it into any unit as I am not comfortable with my rehardening method here and it would be need and done properly to complete this mod and I don't have that yet short of sending out which is cost and time prohibitive.
Anyway just a tech note for the thread.

A note some parts of the thread have gotten off topic so later I may take the tech stuff from myself and everyone who has contributed and repost with the non tech deleted. of course all still attributed to each person. Thoughts on this ?

 

Yep
Because they are same
Ball bearing turbo used so little orifice that bearings use splashing lubrication
And it strictly forbidden to enlarge orifice because too much oil will definitely kill ***** roundness in the bearings because if they slide instead of roll they got flat notches when they contacted race again
So they splash oiled
Same as planets where you have feed line inside shaft and orifices to distribute oil

 

Its my trannys and I make my experiments )
I also used 0.005 to whole unit years ago when build it
My theory that output shaft enlarges ? Why it shouldnt ?
Close to zero not = zero
I mean close to 0.005 that literally as zero in comparison to 0.05 OEM and make input shaft slightly bigger end gap to relief 2 front bearings from load of planets due to their size (and parking gear bearing)
I think when side force locked at output shaft its not loading case
Since all components at output assy from steel they expands equally and clearance not changes dramatically
And I see no reason not to check it because its mine -for clients I always do in OEM specs (because almost all of them out of specs to bigger gap than allowed)

 

Its me again )
I wanna prepare my next build for LS -so it needs to withstand 7k+
Reverse input drum - drill 0.02 in the corner of drum and not blocking OEM holes in the piston or block piston holes and drill 0.035 in the corner ?
3-4 piston leave as is and drill 0.02 in the corner or replace relief ball in piston to plug and drill 0.035 in the corner of drum (near seal ) ?
7cs springs will be added of course
What to choose ? )

 

1-I would not block the hole in the rev piston but would down size it by whatever the amount your corner hole is. - I am assuming you must plan extreme high rpm and doing this to avoid centrifugal apply ?
2 - 3-4 I would keep release check valve but block the little orifice bleed plug in drum and drill the corner is possible to no more than that size. That way the expected fluid loss would remain factory but accomplish your goal.

Curious see pics of this and how accomplished as I have had no luck at drilling either of those in holes that small . Though never did the rev drum as didn't see as issue with exception of tranbrakes as I think the spin up on released and resulting wall climb is what I have noted causes the rev frictions to have burnish on them when used with brakes. Just could not figure a way to drill/
The 3-4 also is a great Idea i wanted to do but could not geta clean drill on it as to me my drilled wont fit inside drum and figuring out the position to drill from outside and land in the right place from outside i had no success with. Either landed in wrong spot or broke tiny bit before coming through When I tried multiple times with an old drum I had .
I then decided larger hole with cup plug orifice put in from outside of drum would be easier . But then got busy and never followed up.
THE DOWN SIDE OF WORKING FOR SOMEONE AS I WAS AT THE TIME, THEY DONT WANT TO GIVE TIME FOR SUCH THINGS AND WHEN YOU WORK FOR YOURSELF LIKE I DO NOW , FINDING THE TIME BECOMES THE ISSUE.

 

We have 2 orifices in 3rd feed (one is servo and second is input drum) and they worked as air bleeder
We also have it in 4th feed to 3-4 accum that many mistakenly count as lube hole to lube lo/rev clutch pack
All air bleeders located on top
GM not put them just for nothing
I think better not to block bleeder inside input drum
I already have 3rd feed 0.100 and it looks like its not harsh at all -thanks to 0.02 clearance 3-4 clutch pack
I think 0.02 hole will not hurt to input drum or even 0.03 because in comparison to 0.100 it has 9% of area (and 0.02 has 4%)
__________________________________________________ ___________________________________
Right tool for every job ) It can use drill bit from 0.01

 

The 3-4 accumulator is not related to 3-4 oil nor the orifice in the bore that would be 4th oil only . And while the feed might not be intended to lube rear planet that is where it sprays,
The orifice in the servo bore IMO does remove air air sprays the band but not in a very beneficial way.
Have you calculated the presure loss of a 4 percent leak by the piston area. frictions and steels ? For example regardless of the feed size unless the leak exceeds it the final apply will be equal to line minus whatever is leaked off . There top or bottom that orifice would be would depend on where the drum is in rotation at any given moment, When assembled it sprays somewhat randomly into the center area of the rev drum. I also follow the rule as much as possible on the 3-4 clutch as it is already plagued with places to leak . That if you create a new one you need to make it up someplace else. Not like the set has a lot going for it .

But your the one experimenting so go for it however you like. But while I realize 4 percent is not huge and this is not an accurate real loss. To me multiplied by the total area of piston, the multiplication loss with friction. The end game loss seems it would be substantial for a clutch pack already stressed to accomplish it goals due to area .
Yes .020 abouts is where I like my 3-4 set for clearance.

I tried using my Dremel took it was taking forever and kept over heating , I see you have some custom made device and for .010 a really steady hand lol

 

C'mon man I can read hyd schematic to separate 3rd feed oil from 4th that goes to accum ) Its actually GM fault to name 2nd accum like 1-2 and 4th like 3-4
Just wrong naming
In 4l60 we have 1st(fwd) 2nd and 4th accums
And 2nd oil in servo that somehow works as 3rd accum -but in a wierd way
I also forget to mention - I restore my 5/16 checkball to 2nd instead of OEM1/4 with enlarging its hole to 1/4 -looks like it works faster and band releases quickly
--------------------------------
As far as I know pressure will not drop at all if intaking oil flow speed(volume) is enough to compensate losses
--------------------------------
I think 4th accum air bleeder cant reach rear planet or lo/rev frictions due to centrifugal air that was grabbed my moving parts
Its alwas lubed from center to outer dia due to centrifugal force
Its very difficult lo lube from outer dia to center -it will require something like pressure washing pump with pressures like 1500+ psi to achieve enough speed of oil
I definitely will not count air bleeder as good oil lube source at high rpm

It was bought for DIY electronic plates when I was at high school decades ago ) And still helps a lot if I need to make small hole in difficult to reach place
​​​​​​​

 

the accumulation for 3rd using the servo is pretty simple really . The 2nd oil has the servo applied at line pressure, The 3rd oil enters the servo from the inside, The area on the inside is larger than applied area of the 2nd area this does two things it pushed the servo to release it due to more area and because its pushing against a smaller 2nd apply area at line this makes for a metered accumulation based on servo size differential and line pressure. This is why the servo type IE corvette, sonnnax, other stocks affect not only 2nd apply but 3rd apply rates.
Now the superior super servo has no size differential and this is why they send a much stronger release spring and without it the servo will not release . At best without the spring it will end up in some neural condition with the bad left loosely sliding on the drum . I also noted this to a lesser extent with the sonnax servo with its very small ratio change front to rear. Thus why I use a release spring from the 80e and 400 2nd brake band. It also is much stiffer with the sonnax 2nd servo .

Also with the sonnax and superior servos are the only ones I change the factory accumulation feed to the servo on . Superior I make equal the feed and the superior I go with the .083 feed and a .093 release accum side.
Now some think the cushion spring is part of the accum in the vet, sonnax and the version of the superior they now have with it.
It does not not is simply a cushion that acts a bit like a wave plate to reduce hammered impact to band which can rip he lug pads off.
However it does is a part of the second gear band clearance as the band in to applied fulling till that springs out of the picture. Which is why I make such a todo about both the servo spring plate and the 4th servo being in contact with the pin at both locations before setting band clearance. Which is why i have a whole assortment of grade 8 different thickness washers for both locations.
As for the 3-4 oil and leaks, I only know the whole circuit is prone to leaks from check valved to bore plugs to the band pin >HUGE ON HERE FOR 3RD AND 4TH OIL.
Im no physicist but to me the circuit is going to at some point reach pressure saturation that will minus whatever leaks no matter how small they are be he final apply pressure minus the leaks.
But more than that the AFL circuit with the PCM since it cannot measure pressure sets the line pressure based in some range or fixed values of assumed leaks. Now assuming that it just maxes pressure at WOT and that the pump can keep up with the volume then there I would not be so worried about leaks. But that is not the most regular condition . Most times it is just normal driving at which case the computer cannot compensate for a change in volume leaked and this is where I would be concerned . Normal light throttle cruising and inadequate pressure to apply and hold under those conditions.
The PCM can only compensate for slip it can see which is never except in lockup as until 2007 the 60e had no ISS so was engine rpm verses whatever stall speed.the slip would have to be huge to be picked up on if the PCM even looks prior to lockup which I doubt and that is why you only see P1870 CODES after getting to lockup and in 4th gear and with very high stalls on the 2-3 shift and the PCM the shift did not happen and setting P0787 I think that is it, Shift solenoid B stuck on when its not. .

Im just really particular about leaks in the 3-4 circuit is all.

Used to be you could just drill some big holes and go, But now so many different wear and erosion leaks BORE PLUGS, END CAPS, VALVES, PR VAVE, BOOST VALVE, BAND PIN BORE , AFL , DRUM TO SHAFT, STATOR TO PUMP BACK and of course release check valves they accumulate to one pretty large leak . So I just address then all and more to make extra sure. Example used to be I would just air check the 3rd apply in shaft and look for drum leaks in tear down But after playing with the drum at various temps I learned a room temp drum can be perfect, put it in the oven to 200f and leak like a siff. so I remove every shaft now and reseal with the seal/retainer green, Same with pump stator. PERHAPS I am just overly paranoid lol. I just do all cause its faster heating them all etc and testing .
Particularly with very high HP units that need more than stock friction numbers thus thin steels and frictions, Very limited heat dissipation, The additional area is needed to hold at WOT but you cant afford any slip aka (smooth shift)at cursing cycling as they cannot dissipate the heat and one hot they are toast.)

 

I know that my Father experimented with both a 0.060" bleed and a 0.030" bleed under the 3-4 apply piston.

His notes say that overall he felt that it was not of benefit, and was unhappy to have worked so hard to seal up the 3-4 circuit, just to drill another leak into it.
Instead he machined some more rigid aluminum spring retainers and used even firmer 3-4 return springs.
He says that the original spring retainers struggle with the TransGo return springs, and the firmer springs would have never held in the OEM retainers.

 

I not used it and I think will not be needed cuz extra large 2nd will definitely kicks at any throttle and my car not for race only

I think too that cushion spring affects because it soften pressure rise inside servo 3rd volume
But with 0.093 band release I achieved 3-2 flare and kick
Annoying and not safe for band
Transgo separator 46-96 has smaller dia of 2nd checkball hole than OEM -I think they tried to slow down servo release at 2-3 shift
_________________________________________

I saw lovely sounded LS3 with ITB at 8500+ for drift animal
Looks like better to hold in mind 9k ready build )

 

Regarding the Reverse-Input Drum; He and Dana (PBA) decided awhile back that they were unhappy with the Belleville-Steel Plate.
And very much disliked the outdated recommendation of restricting the Bleed-Holes in the aluminum Apply Piston for Reverse-Input.

They both would go back to the Early THM700-R4 Waved-Steel Plate, along with the Early THM700-R4 thicker Clutch stack.

My Father then did away with the "Feed-Bleed" design.
He installed a set-screw in the Apply Piston Bleed and installed a tradition Check-ball Capsule in the Apply Piston.
In addition drilled a 0.030" Bleed hole under the Apply Piston with firmer Return Springs for High RPM and Trans-Brake use.

 

Many, many Parts/ Components within automobiles have more than one name, especially those that have longer more complicated names.
Example: the Valve-Body Fluid Pressure Manifold Switch Assembly.

So something like the Second Gear Accumulator Assembly is often referred to as the 1-2 Accumulator, as the corresponding circuit functions during the 1-2 Up-Shift.