Transmission/ PTU modification

[Crash712us]

No your absolutely correct ecoboostsho, torque is controlled at rear dif. There is a electro magnetic coupling just in front of rear dif and it does have a electrical connection. Which this has given me a Idea and there many post spread out all over that details the SHO drive line, and think such information ought put into a sticky. Rather than search countless threads in which may stumble upon it.

[Crash712us]

Here is a link that details the rear dif.

 

http://www.shoforum.com/showthread.php?t=119781

[ShoBoat]

Ok brain fart here. Is there something similar in the front end? How does the system reduce power to the front wheels? So the transfer case has no baring on the amount of power being distributed? Sorry for the questions. In the old days AWD meant the the amount of power distribution happened in the transfer case not the diffs.

[EcoBoostSHO]

I just found that thread and went back and re-read the other 5 pages of this thread and it definitely looks like we should be looking at the rear diff (well the coupling in front of it). I went out on JTEKT website (followed thread from the other forum) and they make two units...one that varies the torque and the other that is essentially a lock up...I'm pretty sure our setup would be the former. It specifically states you can vary the torque to that unit (assuming it is what we have in there). A wiring diagram of the rear diff off an Explorer (even the 11) vs a 2010-12 SHO would help us get to the bottom of if this is just wiring or code...or maybe both.

 

If it's a variable signal (like a pulse width modulated control signal) then you could either change this in the software OR you could in theory create a separate dial/controller and do it directly. Not sure what that would do to the PCM if it didn't get any feedback etc...

 

Ultimately if the rear "clutches" can only hold 150 ft. lbs of relative engine torque (actual torque would be multiplied by the transmission and PTU ratios) then electronics may not do it. BUT if you can do it in the explorer and the part numbers for the rear coupler/diff are the same then it should be possible to send more torque back there.

[EcoBoostSHO]

http://www.autonews.com/assets/PDF/CA69084324.PDF

 

Interesting...definitely indicates that JTEKT is the supplier (I realize we knew that already but thought the overall picture was interesting...

[EcoBoostSHO]

Ok brain fart here. Is there something similar in the front end? How does the system reduce power to the front wheels? So the transfer case has no baring on the amount of power being distributed? Sorry for the questions. In the old days AWD meant the the amount of power distribution happened in the transfer case not the diffs.

 

I don't think it does reduce power to the front wheels directly (mechanically). If the system detects slip to the front it tries to send it rearward...if things are still spinning traction control kicks in and starts pulling timing, injectors, etc...to reduce overall engine power.

 

I do see you have 2013 and I also know those use braking for distributing torque between the wheels for better cornering...but my brain can't handle that additional variable right now so I'm going to ignore it.

[ShoBoat]

Good discussion' date=' I found 2x2013 Explorer Sport V6 near me at a dealer, I'll have to talk them into a LONG test drive so I can look at the differences between the two PTU and controllers [/quote']

 

When you drive it pay attention to the intelligent 4wd display in the left cluster. You can find it after cycling past the tach. In our 2011 if you launch it hard in sand mode the display shows more power going to the rear wheels (the display only changes under load). How it performs this is a mystery to me (of course it could be BS). That said I have played around in the snow in sand mode and it seemed like the rears were spinning faster/harder than the fronts. I am still completely baffled how it performs this function. From what I have read in the JTEKT site and other info I am thinking that the max power would be a 50/50 split? Like EcoBoostSho said if the system starts pulling overall power out to acomplish the illusion of more power to the rears this doesn't help us at all. Although a 50/50 launch is still better than front first then transferred to the rears as the fronts spin. I need to find some sand or mud to try it out in our 2011 explorer again.

 

[ATTACH=CONFIG]2247[/ATTACH]

[ShoBoat]

More info, just came out:

http://wardsauto.com/vehicles-amp-technology/demand-growing-ford-s-intelligent-all-wheel-drive-system

 

Ok now I am confused! :RpS_crying: "For example, if the front of the vehicle is on ice and the rear on pavement, the new system can send 100% torque to the rear of the vehicle." this was in the article on the explorer. Sounds great! If it's true.

 

However down the bottom of the article "The new AWD system was developed for multiple vehicle segments. Originally offered on the Escape and Flex cross/utility vehicles, the Taurus fullsize sedan and some Lincoln vehicles, it not is available on the Explorer and Expedition SUVs, F-150 pickup and Edge CUV." This makes no sense, the whole article talks about how the system is fit in any car or truck Ford needs. And then not...... I thought the new Explorer is built on the Taurus plat form and the new Explorer sport is basically a Explorer SHO is it not?

 

Upon further research here is what I found.

 

http://www.carthrottle.com/the-carthrottle-guide-to-awd-luxury-sedans/

 

"But the twin-turbo SHO exhibits noticeable torque steer on heavy throttle input while cornering, somewhat like an old Turbo Saab – something AWD cars shouldn’t do. There’s no center differential; instead the SHO uses a clutch-type transfer case built into the transmission to regulate front-to-rear power distribution. It’s similar in design to Honda’s RT4WD, and functionally to Haldex, while not working as well as either. Sure, it prevents the SHO from nuking it’s tires to death with 350lb-ft of torque at 1,500rpm, but it leaves a lot to be desired in the snow."

 

BTW this guy has no idea what he is talking about, I have had many 4wd trucks in the past (Explorer, Lincoln Mark LT, Cadillac SRX and Escalade, Dodge Ram and more jeeps that I want to admit) This past winter the only truck I found better than my SHO was my Mark LT That was a beast in the snow.

 

The big item here is that according to this guy (who likes European cars) is that there is a clutch built into the transmission that regulates the power to the fronts. This looks like what we were looking for. This would mean that more than 50% can be truly sent to the rears.

[EcoBoostSHO]

Ok now I am confused! :RpS_crying: "For example, if the front of the vehicle is on ice and the rear on pavement, the new system can send 100% torque to the rear of the vehicle." this was in the article on the explorer. Sounds great! If it's true.

 

However down the bottom of the article "The new AWD system was developed for multiple vehicle segments. Originally offered on the Escape and Flex cross/utility vehicles, the Taurus fullsize sedan and some Lincoln vehicles, it not is available on the Explorer and Expedition SUVs, F-150 pickup and Edge CUV." This makes no sense, the whole article talks about how the system is fit in any car or truck Ford needs. And then not...... I thought the new Explorer is built on the Taurus plat form and the new Explorer sport is basically a Explorer SHO is it not?

 

Upon further research here is what I found.

 

http://www.carthrottle.com/the-carthrottle-guide-to-awd-luxury-sedans/

 

"But the twin-turbo SHO exhibits noticeable torque steer on heavy throttle input while cornering, somewhat like an old Turbo Saab – something AWD cars shouldn’t do. There’s no center differential; instead the SHO uses a clutch-type transfer case built into the transmission to regulate front-to-rear power distribution. It’s similar in design to Honda’s RT4WD, and functionally to Haldex, while not working as well as either. Sure, it prevents the SHO from nuking it’s tires to death with 350lb-ft of torque at 1,500rpm, but it leaves a lot to be desired in the snow."

 

BTW this guy has no idea what he is talking about, I have had many 4wd trucks in the past (Explorer, Lincoln Mark LT, Cadillac SRX and Escalade, Dodge Ram and more jeeps that I want to admit) This past winter the only truck I found better than my SHO was my Mark LT That was a beast in the snow.

 

The big item here is that according to this guy (who likes European cars) is that there is a clutch built into the transmission that regulates the power to the fronts. This looks like what we were looking for. This would mean that more than 50% can be truly sent to the rears.

 

Well I believe we KNOW there is a unit at the rear diff for engaging the rear wheels. (at least from that other forum thread showing the rear end and the subsequent discussion) There "may" be a clutch up front I suppose but I don't necessarily see how we know that for sure...as you stated I don't know that this guy knows exactly how our setup works.

[EcoBoostSHO]

Those last two articles seem to be in direct contradiction to each other. Granted one is about the new Explorer and the other about the SHO. We are definitely going to have to get under the car and just look at it for starters. I will try and get under my SHO this evening to get a clear shot of the rear diff and at least for electrical connectors....hopefully 12shoman will have some good things to report back as well.

[ShoBoat]

Those last two articles seem to be in direct contradiction to each other. Granted one is about the new Explorer and the other about the SHO. We are definitely going to have to get under the car and just look at it for starters. I will try and get under my SHO this evening to get a clear shot of the rear diff and at least for electrical connectors....hopefully 12shoman will have some good things to report back as well.

 

Well good news on that front, I will be at Livernois Motorsports this Saturday getting my exhaust and tune done! :thumb: We will have a good look at the underside of the car, I'll take a bunch of pictures and will definitely ask lots of questions. I am really curious on how the AWD system works. I'll report back to you guys on what I find out.

[EcoBoostSHO]

So I crawled under the rear end and you can clearly see the JTEKT unit (has a sticker that said JTAC####) in front of the rear end. There is a single connector and just a pair of wires that goes to the unit. I saw no other connections in the vicinity.

 

[ATTACH=CONFIG]2248[/ATTACH]

 

This is a pic of the connector on the top of the unit. Pic itself was taken from under the car looking up and being that it wasn't on a lift I couldn't get much further away but the connector is right above where the JTEKT unit connects to the rear end. Since its just two wires it is either an on off unit or a variable current solenoid for an electromagnetic clutch that could be modulated by a controller. The wires go to the front of the car as part of a bigger wiring harness...I didn't follow them all the way to the source given that it wasn't on a lift. I would really really like to hook up a Fluke meter to it while driving (I have one at work) to see what the signal does but I don't know that I will be able to do that easily given its location and the moving parts etc...I would love to see if its a modulated signal or a straight +12 or +5 volts when it "locks" in the rears.

 

I'm just speculating but if this can be controlled via a controller AND it is not physically limited to 150 ft. lbs of torque then I see no reason why it isn't feasible to increase the front/rear torque split at least to a 50/50 configuration.

 

The one thing I am starting to wonder about is some of the other vehicles that apparently do have this setup have a cooled PTU...keeping this locked up could generate significant heat in the PTU and we already know it doesn't like heat. Maybe that is why Ford limited it on our car? (well that and this car is inherently FWD)

 

Hope you guys can find out some more from your investigations.

 

If you have the car on a lift it would be ideal to see where those two wires "end up"...if its the PCM or some other control module. If it's the ECM then someone (i.e. Livernois or someone with similar skill) would just have to map out the appropriate tables (no small feat given how many there are with no available information on them) and be willing to start testing.

[EcoBoostSHO]

Given the connector on top of the unit and the fact that JTEKT only seems to make two different units (see link)

 

http://www.jtekt.co.jp/e/products/4wd02.html

 

I believe we have the E-RBC unit and not the Intelligent Torque Controlled Coupling (ITCC) unit which looks like it has some electronics built in to it. If that is true then this is a much "simpler" setup than some of us may be thinking and I don't know how variable this will be after all.

 

Maybe there really is something up front in the transmission that controls the torque distribution and this just engages the rear wheels period. I wish I could find a data sheet on these units...Its frustrating they don't really produce them for the public...but understandable I suppose. Still would like to know if this is an on/off unit or a modulated one. that would tell us a lot.

[thePUNISHER]

this literature is from the 13 explorer workshop manual; this info is not so in depth in the SHO manuals:

 

 

 

The vehicle is equipped with an AWD system that continuously monitors vehicle conditions and automatically adjusts the power distribution between the front and rear wheels. The system is always active and only requires the operator to select terrain.

 

During normal operation, most of the torque is delivered to the front wheels. If wheel slip between the front and rear wheels is detected, or if the vehicle is under acceleration, the PCM commands torque delivery to the rear wheels to prevent or control wheel slip. When the AWD system is functioning properly, there should be no perceived speed difference between the front and rear axles when launching or driving the vehicle on any uniform surface. Traction should be similar to a part time 4WD system in 4H (4X4 HIGH), but have no binding in turns.

 

All AWD control logic resides in the PCM . The PCM continuously calculates if torque is required at the rear wheels and when torque is required, sends a low-current PWM signal to the AWD relay module over a hard wired circuit. The AWD relay module then outputs a high-current PWM signal which varies the current and duty cycle sent to the ATC solenoid, which is located inside the rear axle.

 

The PWM current supplied to the ATC solenoid increases as demand for rear wheel torque increases. The AWD relay module returns a signal to the PCM throughout AWD operation over a hard-wired circuit to monitor system capabilities.

 

AWD faults are indicated by the powertrain malfunction (wrench) warning indicator in the IPC as well as the CHECK AWD warning indicator in the message center.

 

A spare tire of a different size other than the tire provided should never be used. A dissimilar spare tire size (other than the spare tire provided) or major dissimilar tire sizes between the front and rear axles could cause the AWD system to stop functioning correctly. If the incorrect spare tire or dissimilar tire sizes between the front and rear axles is installed, the AWD system disables automatically and enters FWD only mode to protect driveline components. This condition could be indicated by an AWD OFF message in the message center. If there is an AWD OFF message in the message center from using the spare tire, this message should disappear after reinstalling the repaired or replaced normal road tire and driving a short distance. It is recommended to reinstall the repaired or replaced road tire as soon as possible.

 

The PCM also provides the ABS with its current clutch duty cycle and determines whether or not the ABS may take command of the clutch duty cycle.

 

The active, on-demand AWD system uses data from other systems as inputs to the PCM . The PCM uses the inputs to determine the appropriate duty cycle to send to the AWD relay module and ATC solenoid that delivers the desired torque to the rear wheels. Specific inputs to the PCM are:

 

ATCM switch mode via the HS-CAN .

Engine off status from the BCM-B via the HS-CAN .

Steering wheel angle from the ABS module via the HS-CAN

Yaw rate and Lateral acceleration from the Restraints Control Module via the HS-CAN .

Brake system status from the ABS module via the HS-CAN .

Wheel speed from all 4 wheels from the ABS module via the HS-CAN .

AWD relay module diagnostic.

PCM outputs are:

 

PWM signal to the AWD relay module to the ATC solenoid for control of the solid-state clutch.

Amount of torque transfer commanded signal to the ABS module via the HS-CAN .

AWD system information to the IPC via the HS-CAN .

Returns terrain mode status and ready for change information to the ATCM via the HS-CAN .

Terrain Management

 

 

Based on road conditions, the driver selects what mode the system is in by moving the ATCM switch. The ATCM sends information via the HS-CAN to the:

 

IPC .

ABS module.

PCM .

The AWD system adapts the responses of the vehicle’s engine, transmission, suspension and stability control systems to match the demands of the terrain based on the ATCM switch positions:

 

NOTE: Cruise control is available only in Normal and Snow modes.

 

NOTE: The Mud/Ruts and Sand modes are for off-road use only.

 

NOTE: Use Normal mode when towing a trailer.

 

Normal - This mode is for on-road conditions. If not already active, Normal should be selected before driving on surfaces which are similar to a hard road surface. This mode should be selected once the need for a special mode has passed.

Grass/Gravel/Snow - This mode should be used where a firm surface is covered with loose or slippery material. Surfaces covered in packed snow, ice, water, grass, gravel, or a thin coating of sand for example. For deep gravel, it is recommended that the Sand mode is selected. If the vehicle is unable to gain traction in deep snow, switching traction control off may help. Traction control should be switched on again as soon as the difficulty is overcome.

Sand - This mode should be used for soft dry sand, or deep gravel terrain. If the sand to be crossed is damp/wet, and sufficiently deep enough to cause the wheels to sink into the surface, the Mud/Ruts mode should be selected.

Mud/Ruts - This mode should be used for muddy, rutted, soft, or uneven terrain.

[Crash712us]

I believe I read before they coupling is modulated and the rear end is capable of handling 600ft/lbs of torque. I will have try to find that info again. But you onto something with voltmeter I would have been wanting to do the same thing, like said we should varying voltage signal. If this so a 12 volt signal should achieve maximum lockup of the coupling. So in theory we should be able to install a switch in cabin and wire into wire harness with some diodes so not back feed into module or whatever controls it and achieve max lockup at the flick of a switch.

[EcoBoostSHO]

I believe I read before they coupling is modulated and the rear end is capable of handling 600ft/lbs of torque. I will have try to find that info again. But you onto something with voltmeter I would have been wanting to do the same thing' date=' like said we should varying voltage signal. If this so a 12 volt signal should achieve maximum lockup of the coupling. So in theory we should be able to install a switch in cabin and wire into wire harness with some diodes so not back feed into module or whatever controls it and achieve max lockup at the flick of a switch.[/quote']

 

If you could find that info again that would be awesome. I remember reading that in another thread but there wasn't any actual link to it. Well if its a PWM (Pulse width modulated) signal then a voltmeter won't totally cut it. It would probably give you a voltage measurement but it wouldn't really give you the full picture since this is a signal and not just a on/off thing. The Fluke I was going to use is more of an oscilloscope which would look at the frequency of the square wave it is sending the ATC unit. This would tell you what the duty cycle of the wave is (i.e. 50% on vs 50% off which would say it could still be cranked up. ) I don't know if it would handle a constant 12V without shorting out the solenoid so I would definitely NOT recommend trying that! (Not that anyone was going to but I'd hate to have someone mess something up) It might not even be 12 volts...

 

That description of the 2013 is awesome! Big question is - is the SHO the same or not. I would certainly think it would be but don't know how to verify it. There is probably a look up table that could be modified but as mentioned above finding it would be non-trivial without some info from Ford or a reliable source.

[thePUNISHER]

The sho will operate slightly differet due to the abscence of terrain managment...

 

The signal is not pulse width modulated... It is a variable current ,controlled vIa module. It will most likely use a solenoid proportional to current...

[dsouth77]

[ATTACH=CONFIG]2250[/ATTACH]

 

pic of rear

[EcoBoostSHO]

The sho will operate slightly differet due to the abscence of terrain managment...

 

The signal is not pulse width modulated... It is a variable current ,controlled vIa module. It will most likely use a solenoid proportional to current...

 

Thanks! Do you know which module? The ECM?

[FoMoCoSho]

For troubleshooting AWD binding problems, techs are able to send 90% of the power to the rear via IDS and the active torque coupler.

[thePUNISHER]

For troubleshooting AWD binding problems' date=' techs are able to send 90% of the power to the rear via IDS and the active torque coupler.[/quote']

 

its impossible to send 90% of the power to the rear....because the front wheel drive transmission is what drives the ptu.....you cant change the output of the 6F55 to each axle....theres no way to manipulte this because a mechanical differential is driving the front halfshafts and ptu.

 

techs can cange the amount of current going to the coupling via ids, but cant decrease the amount of output from the transmission itself....

[ShoBoat]

its impossible to send 90% of the power to the rear....because the front wheel drive transmission is what drives the ptu.....you can change the output of the 6F55 to each axle....theres no way to manipulte this because a mechanical differential is driving the front halfshafts and ptu.

 

techs can cange the amount of current going to the coupling via ids, but cant decrease the amount of output from the transmission itself....

 

Curious, how is this accomplished on the Explorer?

[Crash712us]

I agree with the punisher, best we can do is 50/50.

Since the PTU power takeoff unit gets its power from passenger side drive axle. So there is no physical way to limit power at front wheel and divert to rear wheels.

[thePUNISHER]

I agree with the punisher, best we can do is 50/50.

Since the PTU power takeoff unit gets its power from passenger side drive axle. So there is no physical way to limit power at front wheel and divert to rear wheels.

 

bingo......

[thePUNISHER]

its not...... dd you see this posted somewhere about the explorer??