[Blown7]

So now that we know there are 6 electronic solenoids, all are controlled by the imfamous TCM.

6 Electrical Solenoid Valves
1. (1) Shift pressure Regulator Valve ( Variable Force Valve)
2. (1) Modulating Pressure Solenoid (Variable Force Valve)
3. (1) 3-4 Shift Solenoid
4. (1) 1-2/4-5 Shift Solenoid
5. (1) 2-3 Shift Solenoid
6. (1) Torque Converter Clutch Solenoid (Pulse Width Modulated)


There are also three other electrical circuts,

The Fluid Temperature Sensor,

Two input speed sensors (N3 and N2)

All circuts are routed to the valve body in the transmission by this 13 pin connector (BTW this is the infamous transmission connector O Ring
which if it leaks water in the transmission the transmission is destroyed)

J

 

[navyavi469]

Ok, I understand what a solenoid is... a linear electro-mechanical actuator that uses a loop inductor to create a magnetic field, and accelerates a conductor perpendicular to the plane of electromagnetic potential (use the right hand rule). It basically uses electricity to poke a move a rod.

So what do these solenoids do, they engage somehow to shift one drive gear to the next? And when you say Torque converter lockup.... a torque converter is just two turbines, symetrically inversed, and facing one another in a closed bath of hydraulic fluid... a fluid "coupler" if you will. But what makes it "lock up", is there a physical connection between the fans or a clutch that engages somewhere?

 

[Blown7]

Ok, I understand what a solenoid is... a linear electro-mechanical actuator that uses a loop inductor to create a magnetic field, and accelerates a conductor perpendicular to the plane of electromagnetic potential (use the right hand rule). It basically uses electricity to poke a move a rod. ?

Yeppers they are a electrical valve, kind of like turning your kitchen sink Hot or Cold water on not by turning by using your hand to turn the handle but by using a magnet, coil, plunger and switch.

Here's a copy and paste from a manual I have
The typical electrical solenoid used in automotive applications is a linear actuator. It is a device that produces motion in a straight line. This straight line motion can be either forward or backward in direction, and short or long distance.

A solenoid is an electromechanical device that uses a magnetic force to perform work. It consists of a coil of wire, wrapped around a magnetic core made from steel or iron, and a spring loaded, movable plunger, which performs the work, or straight line motion. The shift valves (solenoids) are On-Off solenoids and are powered up by the TCM with a 12-volt power source and are internally grounded in the transmission. The Torque Converter Clutch (TCC) and Pressure Control (PC) solenoids are also powered up by the TCM and internally grounded in the transmission but are pulse with modulated (PWM) . PWM measurable voltage varies depending on percentage of modulation requested by the TCM.

The solenoids used in transmission applications are attached to valves which can be classified as normally open or normally closed. The normally open solenoid valve is defined as a valve which allows hydraulic flow when no current or voltage is applied to the solenoid. The normally closed solenoid valve is defined as a valve which does not allow hydraulic flow when no current or voltage is applied to the solenoid. These valves perform hydraulic control functions for the transmission and must therefore be durable and tolerant of dirt particles. For these reasons, the valves have hardened steel poppets and ball valves. The solenoids operate the valves directly, which means that the solenoids must have very high outputs to close the valves against the sizable flow areas and line pressures found in current transmissions. Fast response time is also necessary to ensure accurate control of the transmission.

The strength of the magnetic field is the primary force that determines the speed of operation in a particular solenoid design. A stronger magnetic field will cause the plunger to move at a greater speed than a weaker one. There are basically two ways to increase the force of the magnetic field:

Increase the amount of current applied to the coil or
Increase the number of turns of wire in the coil.
The most common practice is to increase the number of turns by using thin wire that can completely fill the available space within the solenoid housing. The strength of the spring and the length of the plunger also contribute to the response speed possible by a particular solenoid design.

A solenoid can also be described by the method by which it is controlled. Some of the possibilities include variable force, pulse-width modulated, constant ON, or duty cycle. The variable force and pulse-width modulated versions utilize similar methods to control the current flow through the solenoid to position the solenoid plunger at a desired position somewhere between full ON and full OFF. The constant ON and duty cycled versions control the voltage across the solenoid to allow either full flow or no flow through the solenoid's valve.

So what do these solenoids do, they engage somehow to shift one drive gear to the next? And when you say Torque converter lockup.... a torque converter is just two turbines, symetrically inversed, and facing one another in a closed bath of hydraulic fluid... a fluid "coupler" if you will. But what makes it "lock up", is there a physical connection between the fans or a clutch that engages somewhere?

The next question you have is where things get a little complicated.

I'll answer this in another post


J

 

[Blown7]

Here's a cutaway pic of the various solenoids



MODULATING PRESSURE CONTROL SOLENOID VALVE

The modulating pressure control solenoid valve (1) is located in the shell of the electric valve control unit and pressed against the shift plate by a spring.

Its purpose is control the modulating pressure depending on the continuously changing operating conditions, such as load and gear change.

The modulating pressure regulating solenoid valve (1) has an interference fit and is sealed off to the valve body of the shift plate (4) by a seal (arrow). The contact springs (2) at the solenoid valve engage in a slot in the conductor tracks (3). The force of the contact springs (2) ensures secure contacts.

TORQUE CONVERTER LOCKUP CLUTCH PWM SOLENOID VALVE

The torque converter lockup clutch PWM solenoid valve (1) is located in the shell of the electric valve control unit and pressed against the shift plate by a spring.

The PWM solenoid valve (1) for the torque converter lockup controls the pressure for the torque converter lockup clutch.

The torque converter lockup PWM solenoid valve (1) is sealed off to the valve body of the shift plate (4) by an O-ring (5) and a seal (arrow). The contact springs (2) at the solenoid valve engage in a slot in the conductor tracks (3). The force of the contact springs (2) ensures secure contacts.

SHIFT PRESSURE CONTROL SOLENOID VALVE

The shift pressure control solenoid valve (1) is located in the shell of the electric valve control unit and pressed against the shift plate by a spring.

Its purpose is to control the shift pressure depending on the continuously changing operating conditions, such as load and gear change.

The shift pressure regulating solenoid valve (1) has an interference fit and is sealed off to the valve body of the shift plate (4) by a seal (arrow). The contact springs (2) at the solenoid valve engage in a slot in the conductor tracks (3). The force of the contact springs (2) ensures secure contacts.


UPSHIFT/DOWNSHIFT SOLENOID VALVES

The solenoid valves (1) for upshifts and downshifts are located in the shell of the electric control unit and pressed against the shift plate with a spring.

The solenoid valves (1) initiate the upshift and downshift procedures in the shift plate.

The solenoid valves (1) are sealed off from the valve housing of the shift plate (5) by two O-rings (4, 6). The contact springs (8) at the solenoid valve engage in a slot in the conductor tracks (7). The force of the contact spring (8) ensures safe contacts.


J

 

[Blown-WK]

Nice work Jeff. I understand things much better with pictures

 

[slate5.9]

As has been said before by others, the detailed info is much appreciated. I'm mechanically minded but am blown away (cuz I don't understand all of what you are explaining) & fascinated at the same time. Good to know we have intelligent guys looking out for our beloved rigs but pushing the envelope as well.

 

[BJB]

Alright... You guys are just showing off now!!!

 

[Blown7]

So what do these solenoids do, they engage somehow to shift one drive gear to the next? And when you say Torque converter lockup.... a torque converter is just two turbines, symetrically inversed, and facing one another in a closed bath of hydraulic fluid... a fluid "coupler" if you will. But what makes it "lock up", is there a physical connection between the fans or a clutch that engages somewhere?

.

Now Winston, the questions you asked here just about cover the entire operation of the NAG1 Transmission LOL.

The shifting solenoids (this is where I have to be precise on the solenoid names) open and close much like the facet in the kitchen sink............. either they are "ON" or "OFF"

Either the fluid passage is full, pressure is high (Lots more on these two words in the future) and flowing or it is "OFF" no fluid, no pressure.

Ok simple enough the TCM turns the shifting solenoids on or off.
(This is the last time I'll ever say "Simple Enough" in this thread.)

Now by turning the shifting solenoid "ON" that starts a process that is rather like the "Old Rube Goldberg" drawings

Now you get to learn a whole bunch of new valve names

A. One (1) Manual Valve
B. One (1) Torque Converter Line Pressure Limit Valve
c. One (1) Working Pressure Regulating Valve
D. Three (3) Overlap Regulating Valves
E. One (1) Torque Converter Lock Up Clutch Regulating Valve
F. Three (3) Command Valves
G. Three (3) Holding Pressure Shift Valves
H. Three (3) Shift pressure Shift Valves
I. One (1) Lubrication Pressure Regulating Valve
J. One (1) Shift Pressure Regulating Valve
K. One (1) Regulating Valve Pressure Regulating Valve
L. One (1) Shift Valve Pressure Regulating Valve
M. One (1) B2 Shift Valve
N. Twelve (12) Ball Check Valves

Now in case you haven't noticed some valves have valves and some valves that control other valves and the valves have valves................

And I'll take and show how they all interact.

And that concludes the tech from me for today, now I have to sort out how to run and control my new Southern Hotrod Bullet Blower......

 

[SRT Great]

That "wake me up" thinga ma jig won't work like advertised.......how can you keep water in a paper bag????

Do the solenoids have room to be open/closed faster....and would the applicable fluid paths be able to keep up. I sure would like to be able to manually shift mine without any delay.....is this just a programming issue, or limited by the above. Thanks.

 

[Blown7]

Ah here's that blurb on Chrysler and the warantee charge back

Transmission Mission
Chrysler has a transmission teardown process where returned transmissions are disassembled and road tested, if necessary, to identify root cause of the failure. Proper documentation of the symptoms and fault codes on the diagnostic worksheet is critical in directing teardown and analysis of returned units. Information learned from these teardowns is crucial in identifying and resolving production and design issues. Also as result of such inspections, it has been identified that there are some that are not following the rules. Although there are some very good technicians in the field, sometimes it's seen where a technician has misrepresented or exaggerated a failure in order to justify a transmission replacement rather than a repair. In those instances a chargeback will be issued. The amount charged back could vary anywhere from:
• $75 for not including a diagnostic worksheet.
• Markup cost of the transmission (approx. $800) for failing to meet the 70% rule.
• A full chargeback (approximately $3500) for misrepresenting the failure, sabotage (we've seen units where the tech's have intentionally damaged components or dumped metal shavings into the pan or pump) and non-warrantable damage.
There are many cases where a transmission replacement is performed for nothing more that a simple burnt clutch. Although this can result in clutch material and possibly some metal debris being generated, this is not justification for a transmission replacement. If the clutch retainer is blackened, it can usually be cleaned and re-used rather than replaced. As long as there is no hard part or gear train failure, it is recommended that the pump and valve body be split and cleaned. The "Group A" repair covers the labor for reconditioning the pump and the "Group C" covers the valve body. If no valves or bores are scored or damaged, those components can be re-used. The torque converter will not require replacement for a clutch failure unless the oil is heavily contaminated (large debris will be trapped by the filter and will not make it into the converter). Most clutch failures can be repaired by simply using the appropriate clutch kit and a pump cover. On 545RFE and 68RFE transmissions, if the root cause of the burnt clutch (cut seal, missing seal ring, stuck valve, etc...) is not found during the repair, it is recommended that the transmission solenoid be replaced as well.
It's understandable that there are times when a trans needs to be replaced for customer satisfaction and that is taken into consideration. If there's an issue where a trans replacement is necessary, it is a good idea to contact the STAR Center so that detailed information can be documented to make it available for engineering to utilize during the teardown process. Also, STAR is aware of many common transmission issues and can assist in directing the repair.
Please pass this information along to any technicians that will be performing transmission warranty repairs.
=====================================
Shifty Business
A transmission had previously been disassembled at the dealership and then was analyzed at the Indiana Transmission Plant on 10/9/07 after it was returned. During the plant inspection, there was metallic (ferrous) debris found in the pan. All the clutches in the transmission were in good condition. The 2C piston had a tear in the OD seal and evidence of debonding. The 2C/4C retainer had been deformed and scratched by the tech during removal at the dealership. All transmission components were inspected to see if any could have been the source of the debris. The torque converter was even split in an attempt to identify the source. There was no failure found inside the transmission or torque converter that could have generated the debris discovered in the pan. Normally, when there is debris in the pan from a failure, there is also debris on the top of the valve body. None was found on the valve body. There was also a significant amount of metal (ferrous) debris found inside the pump. Some of the debris was in the rotor pocket of the pump. (Fig. 1)
4
I can't download the pictures sorry

Due to the debris, it was expected that major scoring of the rotors and rotor pocket would be seen. The pump and rotors were cleaned and found to be in pristine condition. (Fig. 2)
(Fig. 2)

It was concluded that there was no way for the debris to have entered the pump during operation of the transmission. The pump would have to have been split and the debris poured in.
The original failure mode on this unit was determined to be a failed 2C piston OD seal. This unit could have been rebuilt, but instead it appears metal was introduced into the pan and
pump so that a transmission replacement could
be justified. Based on evidence of sabotage, a complete chargeback was issued.
=====================================



J

 

[Blown7]

That "wake me up" thinga ma jig won't work like advertised.......how can you keep water in a paper bag????.

I guess we'll have to dig up Ol' Rube and ask 'em

Do the solenoids have room to be open/closed faster....and would the applicable fluid paths be able to keep up. I sure would like to be able to manually shift mine without any delay.....is this just a programming issue, or limited by the above. Thanks.

I have to be careful here with the answer to your question.

First various solenoids have to be identified that can be "Opened" and "Closed" faster.......

First remeber the only solenoids that get opened and closed are the shifting solonoids. Namely 1-2/4-5, 2-3, 3-4.

Using the TCM calibration, the TCM "timeframe" that opens and closes those valves is about a second and a half.

That means those valves are opened, remain open, and are in the closed position within a second and a half.

Changing those really won't gain any faster shifting, the real answer lies with the Line Pressure Variable Force Solenoid and the Shift Pressure Varible Force Solonoid which are Pulse Width Modulated. Changing those change everything and IMHO with a little valve modification also.


Bottom line it's all in the TCM programming and how much of the Mercedes algorithm and engine load tables that can be adjusted, I myself think that will be difficult to tune the OEM Daimler/Chrysler operating system properly.


That's why I have started on the transmission stuff now. As the PCM/TCM/FDCM New Stand Alone Control will also control the NAG1 transmission and I have to create Truth Tables to operate this transmission.

So thats why I decided to start this thread now, I might as well share some info.

Jeff

 

[1621]

listen all of y'all it's a sabotage

 

[BuilderBill]

listen all of y'all it's a sabotage

Eddie and I are guilty as charged.
On a core we look at the history of the unit....broken hard parts for example and we pitch 90% of the complete transmission.
Sure is less expensive to us rather than having a bunch of junk out there.
Bill

 

[NeverFastEnough]

listen all of y'all it's a sabotage

Nice B-Boys reference! Anyway, this thread just keeps getting fascinating. I hope one day I can fully understand it all.

 

[Flanman]

So Jeff, what can you tell us about the effects of trans fluid temperature on trans function since this one of the inputs the TCM uses to adjust shift quality. At what temp does the TCM start modifying the shifts to protect itself? In other words, what temp do we want to keep our trans fluid below?

 

[Blown7]

So Jeff, what can you tell us about the effects of trans fluid temperature on trans function since this one of the inputs the TCM uses to adjust shift quality. At what temp does the TCM start modifying the shifts to protect itself? In other words, what temp do we want to keep our trans fluid below?

140 Degrees F is tha magic number which is where the adaptives start getting stored in memory which is a temperature that is quite hard to keep below.

Transmission upshift adaptation occurs between (140°F) and less than 100°C
(212°F).


Coastdown adaptation occurs with temps greater than 60°C (140°F) and less than 70°C (158°F).

J

 

[Blown7]

BTW here's a neat link to a homemade transmission dipstick tool on the LX site

http://www.lxforums.com/board/showthread.php?t=126375

 

[navyavi469]

Jeff by the end of this thread I expect the average forum member to be able to field strip a NAG1 and rebuild the converter.

Oh FYI, I put an autometer stand-alone tranny temp gauge in my pan... thought it would be cool. Runs at 160 almost constnatly.

 

[BuilderBill]

Jeff by the end of this thread I expect the average forum member to be able to field strip a NAG1 and rebuild the converter.

Oh FYI, I put an autometer stand-alone tranny temp gauge in my pan... thought it would be cool. Runs at 160 almost constantly.

Oh wise one....tell me you didn't. Temp gauge in the pan??
With all the electronics available (dashhwak etc...Star Mobile, laptop programs)????
Extremely confused!

BTW...when you "change or modify" the line or shift pressure solenoids, it also makes the downshifts VERY harsh.
Please look at working with "UV" and doing this electronically.
Bill

 

[Blown7]

!

BTW...when you "change or modify" the line or shift pressure solenoids, it also makes the downshifts VERY harsh.
Please look at working with "UV" and doing this electronically.
Bill

Absolutely!

The whole tuning ballgame with changing the shifting stratagy in the NAG1 transmission with any success relies on those "two little solenoids". And that requires a whole bunch of new transmission software operating system, I'm finally getting even "UV" as smart as he is, to understand all that !

Actually that was one and will be one of the main points of this WHOLE thread, that full shifting control of the NAG1 is based on those solenoids!

This ain't your daddy's GM Turbo Hydro 350

Remember those two solenoids are Pulse Width Modulated which means they are never fully open or closed at any time. The plunger (valve) is constantly adjusted at the rate of 1000 hertz based on the TCM high drive circut control which is controlled by the TCM calibration.
That's why it was necessary that you drilled and tapped one of your cases so that we could get some hard pressure data that could be logged with transducers to understand the transmission pressures at any given driving stratagy.

This is why I surmise Daimler would never allow BJB to have a fully race ready TCM, imagine how easy it would be to hack a race ready TCM and just get the absolutely least amount of calibration code needed to make a NAG1 work under those circumstances? Without any adaptive control?

That TCM alone would probably brankrupt Chrysler and Mercedes in warantee work, and make B a very wealthy man.


J