Educate me please. E4od's and torque converters

[lilredtdi]

Read the tech section about the e4od tranny and the lock/unlock mod. I read it twice. The WHOLE thread! My flame suit is on.............

I have no idea how torque converters work to begin with and that thread confused me even more. Can someone please explain what the mod does and how a torque converter works? Please.

If anyone can explain how a stall converter works in a dragster that would be interesting to know also.



Thanks and be easy on me

 

[GOOSE]

From what I understand, put the brakes on and mash the pedal in drive. The rpm's you see is your stall speed. Small block gassers like a high stall speed to get into their powerband, diesels like a low stall speed to use the torque they generate to its advantage.

 

[FORDF250HDXLT]

http://youtu.be/QIobzoSGhy4

http://youtu.be/MvLoX0z9qoY

http://www.bankspower.com/techarticles/show/9-Understanding-Torque-Converters

http://www.bankspower.com/techarticles/show/10-understanding-stall-speed


for what it's worth,iv never understood the desire to mess with the lock/unlock state of the converters lockup clutch.if your e40d's electrical system is working correctly,you couldn't possibly manually control it as quick and good as the ecm can.

 

[Wyreth]

Firstly understand I only have a fuzzy understanding of what goes on inside a converter. This is what I believe happens inside that little taurus of doom:

Basically it's a hydraulic controlled clutch pack. Much like what is inside the transmission. However it has a turbine that generates the pressure to engage. The faster the engine turns the turbine in the housing, the harder it presses on the clutch, transferring power to the input shaft of the transmission. A torque converter will never "lock" like a clutch normally. The E40D's converter uses some form of dark magic I've not looked into, that effectively locks the internal turbine/clutch setup. Making it not a torque converter anymore, this eliminates the powerloss form the converter's inherent slipping. Improving fuel mileage, and giving you more power at the wheels.

The lockup mod lets YOU control when the TC locks and unlocks. Which when towing or trying to eek some more mileage when unloaded is pretty useful. Locked your trans will produce more heat, which is your enemy when towing, so now you can unlock it under high stress at points where the computer wouldn't normally. When pulling a grade, this can save your trans. When you're empty, you can lock it just puttering around, where the computer wouldn't normally lock the TC, and now you're using less fuel.

Or so I am led to believe.

also, since when have we needed flame suits around here?

 

[international]

Umm, won't an unlocked TC generate more heat than a locked one. Unlocked = slippage = heat.

 

[lilredtdi]

Thanks for all of the replies. I never realized that the torque converter was such a complicated piece. I assume the liquid inside is tranny fluid? And with that when doing a tranny fluid/filter change it should be changed as well?????????

How is that done? I noticed a rectangular cover under my truck on the bell housing next to the tranny. I *assume* this must be removed and the starter bumped to find a drain plug???????

In the videos and photos posted I did not see a drain plug so perhaps I am wrong and the TC is not serviceable???

Post 4 if true would be a benefit to me to do this mod. I almost never have more that a couple hundred pounds in the bed. *Usually* I am driving with no load. I am all about conserving fuel if possible.

BTW- It does not always happen but a few times I have noticed some strange behavior in my trucks tranny. Seems if I am babying it for mileage it sometimes hunts for gears around 55-60 mph (no load) and when it does that sometimes the OD light flashes. If I am understanding the mod correctly this is what it corrects.

 

[gandalf]

You mentioned/questioned about doing a fluid change in your E4OD, and I saw the words "...How is that done?" It's actually not a hard job, if you take it slow and easy, read the instructions several times before starting.

OldBull8 wrote a pretty good set of instructions on how to change out the fluid in your E4OD. It's in the tech section. I'll post a link just in case you missed it.

E4OD Fluid Change

 

[trackspeeder]

Firstly understand I only have a fuzzy understanding of what goes on inside a converter. This is what I believe happens inside that little taurus of doom:

Basically it's a hydraulic controlled clutch pack. Much like what is inside the transmission. However it has a turbine that generates the pressure to engage. The faster the engine turns the turbine in the housing, the harder it presses on the clutch, transferring power to the input shaft of the transmission. A torque converter will never "lock" like a clutch normally. The E40D's converter uses some form of dark magic I've not looked into, that effectively locks the internal turbine/clutch setup. Making it not a torque converter anymore, this eliminates the powerloss form the converter's inherent slipping. Improving fuel mileage, and giving you more power at the wheels.

The lockup mod lets YOU control when the TC locks and unlocks. Which when towing or trying to eek some more mileage when unloaded is pretty useful. Locked your trans will produce more heat, which is your enemy when towing, so now you can unlock it under high stress at points where the computer wouldn't normally. When pulling a grade, this can save your trans. When you're empty, you can lock it just puttering around, where the computer wouldn't normally lock the TC, and now you're using less fuel.

Or so I am led to believe.

also, since when have we needed flame suits around here?

Actually the lock up clutch is a separate part of the converter. Turbine speed has no effect on it.

Lock up is determined by the TCM. When conditions are warranted. A signal is sent to the solenoid pack. Lock up solenoid sends fluid to the lock up valve. (in the pump) This will pressurize the lock up piston in the converter. The piston locks up the clutch.

A locked converter will run cooler. Heat is generated by fluid passing between turbine and stator. During lock up these parts are not doing anything.

 

[lilredtdi]

You mentioned/questioned about doing a fluid change in your E4OD, and I saw the words "...How is that done?" It's actually not a hard job, if you take it slow and easy, read the instructions several times before starting.

OldBull8 wrote a pretty good set of instructions on how to change out the fluid in your E4OD. It's in the tech section. I'll post a link just in case you missed it.

E4OD Fluid Change

Holy crap! That sounds like a real PITA. Does not help I have no idea what line does what or where they are located.

That write up does not say anything about the filter or pan gasket.

And, if the torque converter is self contained and not actually a hard part that is bolted to the tranny just riding on tranny input shaft how does this get fluid out of converter?

 

[FORDF250HDXLT]

BTW- It does not always happen but a few times I have noticed some strange behavior in my trucks tranny. Seems if I am babying it for mileage it sometimes hunts for gears around 55-60 mph (no load) and when it does that sometimes the OD light flashes. If I am understanding the mod correctly this is what it corrects.

the correct way would be to resolve the issue rather than try to manually correct it.
the odds are if you used a meter with snapshot or a sensor tester,you would find a dead spot in your fipl/tps.this dead,worn out spot in this sensor right around normal driving speed is probably whats causing your converter to un/lock.
code scanners only cost around 20-30 bucks these days.it's a good tool to have.

don't take this the wrong way please,
but a manual wired un/lockup converter switch is not for you.the odds of several thousands in repair is highly likely,if this warning goes unheeded.resolve any issues,and you'll be pleased with how the ecm safely handles everything.

 

[Dave 001]

Actually the lock up clutch is a separate part of the converter. Turbine speed has no effect on it.

Lock up is determined by the TCM. When conditions are warranted. A signal is sent to the solenoid pack. Lock up solenoid sends fluid to the lock up valve. (in the pump) This will pressurize the lock up piston in the converter. The piston locks up the clutch.
QUOTE]

What he said......

 

[Dave 001]

In very simplified terms, think of a torque converter working this way.....take two window fans and place one in front of the other. When you turn fan "A" on low, the air will blow across fan "B" thus making fan "B" spin. Now imagine fan "B" has a load on it. Fan "B" will spin but it will never spin at the same RPM as fan "A". The difference in speed is known as "slip".

Now put fan "A" on medium...fan "A" spins faster and so does fan "B". Fan "B" although spinning faster will still never spin as fast as fan "A" BUT (and that's a big BUT) the percentage of slip is less.

Now put fan "A" on fast...fan "A" spins even faster and so does fan "B". Fan "B" although spinning faster will still never spin as fast as fan "A" BUT again the percentage of slip is even less than on medium.

The faster you spin fan "A", the faster fan "B" will spin and the less slip there will be, HOWEVER, fan "B" will never, ever spin at the same speed as fan "A". There will always be slip (the drive medium is, after all, nothing but air).

Now enclose both fans in a sealed box. Replace the air with transmission fluid. Replace the box with a leak-proof metal can. Call fan "A" an impeller. Call fan "B" a turbine. The impeller is connected to the engine. The turbine is connected to the gears in the transmission (and onto the driveshaft, differential, axles, and finally the wheels). Congradulations!! You have just made a torque converter. (Actually you made a "fluid coupling"....torque converters were developed several years later in the history of the automatic transmissions but now we're getting rather complicated and that's a subject for another day.)

A torque converter clutch is a friction disc located within a torque converter that will mechanically lock the impeller and the turbine. As mentioned above, there will always be slip in a torque converter (fan "A" and fan "B" never spinning at the same speed.) When the torque converter clutch is locked up, there is a mechanical connection between the two and there is no longer any slip.

Slip in a torque converter "beats" the transmission fluid and creates a lot of heat. On a transmission without a TCC (like a C6) I would estimate that 80% of the heat in the transmission comes from converter slippage. The other 20% from the gears, pump, etc. This is why, for example, an E4OD generates much less heat than a C6.

Eliminating slip also improves MPG. On a transmission without a TCC, the engine must spin a little faster in order to compensate for converter slip. (This is why years ago, if you took to identical cars, one with manual transmission and one with automatic, the manual transmssion'd car got better mileage....because the clutch in the manual tansmission'd car did not have any slippage and the torque converter did. Modern automatics with a TCC have pretty much eliminated the MPG difference.)


OK...now onto stall speed.....going back to fan "A" and fan "B"......there will be a point at which fan "A" is spinning so slow, it will not be blowing enough air to make fan "B" spin. Some where between fan "A" spinning too slow to drive fan "B" and fan "A" spinniing at its maximum but fan "B" still not spinning (because of load) is the stall speed. There are 100's of factors that affect stall speed.....engine speed, engine torque, pitch of the vanes in the torque converter, gearing, weight, etc, etc.

For example, maybe fan "A" needs to spin 500 RPM before fan "B" will start to spin. But if you increase the pitch of the blades on fan "A", fan "B" may start spinning when fan "A" is at only 400 RPM. That second combination has a lower stall speed. (Google "TH400 switch pitch" for an example of this.)


There....it's all as clear mud!!

 

[lilredtdi]

Ahhhhaaaaaaaaa..........I think i get it! That is a really good teaching lesson and should be in the tech section stickied. I am Sure I am not the only one here that does not undrstand.

Thank you kind sir for a good piece of education.

 

[Dave 001]

Holy crap! That sounds like a real PITA. Does not help I have no idea what line does what or where they are located.

As usual, everbody has an opinion. In my opinion, if the converter has a drain plug, don't waste your time doing the cooler line, hose, bucket, engine running, pouring fluid in as it comes out routine (and avoid a huge mess).

Just drain the conveter and the pan. Doing that gets the vast majority of the fluid out.