Single speed vs 2-speed t-case

[gijoecam]

Just curious: I know the '06 and '07 are coming out with a single speed and 2-speed transfer case. Are the V-8s limited to the single-speed, or can you get the 2-speed with the V-8 now?

Just curious is all.... I stumbled on some interesting info on how to manually lock the single-speed t-case into 4 high. Still need to read-up on how it works though...

-Joe

[IAmTodd]

I believe they are offering both the regular 4wd and AWD on the new Explorers, either engine.

I don't see a way to lock the AWD case in. Unless they changed it, it is all mechanical.

[gijoecam]

'06 and '07 are different according to the shop manual.... apparently the Borg Warner 44-11 is a little bit different.... I can't quite tell if it's the same as the 2-speed case but without the reduction gears, or if there's a major difference between them.... Haven't gotten that far into the prints yet.

Here's some interesting info I gleaned about the single-speed t-case on the '06 and '07:

Principles of Operation

The one-speed torque-on-demand (TOD) transfer case modes are controlled through the 4WD control module.

The modes are:

AWD auto — torque is supplied to the front and rear driveshafts only as needed during low traction situations. AWD auto can be switched to lock by pressing the message center SETUP button; the message "AWD AUTO" will be displayed, press RESET within 4 seconds, then the message "AWD LOCKED" will be displayed.
AWD locked — torque is supplied to the front and rear driveshafts constantly and the 4x4 indicator will stay illuminated in the instrument cluster. This mode is not recommended for use on dry pavement or hard surfaces. AWD locked can be cancelled by pressing RESET in the message center; the message center display "AWD LOCKED" will turn off and will return to "AWD AUTO" for 4 seconds when the transfer case clutch disengages.
If the transfer case begins to overheat, the system will default to the Autolock mode. The 4x4 indicator will illuminate in the instrument cluster. This condition may clear without any action being taken by the driver. The 4x4 indicator in the instrument cluster will turn off when the system cools down.

In either case, auto mode is torque-on-demand as in the previous control-trac systems. Gone is the mechanical AWD apparently.

-Joe

[IAmTodd]

Thats dumb. The system is jerky and very inconsistant. Where as the mechanical very is transparent.

[Mbrooks420]

That is a shame. Viscous couplings are the way to go. No wires, computers, or electromagnetic ramp clutches to fail.

[kafir]

is torque-on-demand another way of saying control-trac?
also, how does control-trac know when you've gone from loose surface to hardpack/pavement?

perhaps a link to a control-trac white paper could be useful, if anyone knows where it is. again, i searched & got nuthin useful.

[Mbrooks420]

Control trac is just a Ford term like traction-lok Torque on demand is universal name for "automatic" 4wd. Control trac uses the speed sensors to tell if a wheel is slipping. If there is no slippage the TOD clutch in the t case doesn't power the front axle.

[gijoecam]

Originally Posted by Mbrooks420

Control trac is just a Ford term like traction-lok Torque on demand is universal name for "automatic" 4wd. Control trac uses the speed sensors to tell if a wheel is slipping. If there is no slippage the TOD clutch in the t case doesn't power the front axle.

Actually, when I was under the Ex doing an oil change last weekend, I noticed (for the first time in 8 years) two stickers on the transfer case: Apparently 'Control-Trac' and 'Torque-On-Demand' are both licensed trademarks of the Borg-Warner Corporation (with a whole bunch of patents on the system).

And yes, I think the 44-11 is essentially the 44-05 (2nd-gen Control-Trac) modified for single-speed function, but I can't be sure. I would love to see the two side-by-side and split-open. Anyone with an '06 want to drop their t-case for me and split it open?

[Mbrooks420]

That's wierd since other companies use the term torque on demand. Thats what they called the Polaris atv's 4x4 system when it came out. Maybe they had to quit using it. I fail to see the point of having all the drawbacks of the TOD system, without having the low gear set. Probably just so Ford can cut some costs, and use the same cases and tooling and just leave out the low range parts. Oddly enough this is how Polaris builds their transfer cases. They are all low range cases with 4x4, but the 2wd's are missing the front output.

[gijoecam]

Maybe Polaris uses a B/W t-case? I dunno on that one....

I just poured over the exploded diagrams and yes, it appears that the single speed 44-11 is just a modified 44-05 without a planetary reduction gear, shift motor, and fork assembly. The front half of the case is different based on whether you've got a 4.0 liter with the 5R55 or the 4.6 liter with the 6R60 transmission. They also use a different front output shaft depending, again, on which engine/trans you have.

Unfortunately, it looks like the same ol' Control-Trac case.

The good news is that the BWM should still work so long as you maintain the feedback loop to the 4x4 control module. They changed the wiring aorund a bit, and instead of grounding through the chassis, the ground loop from the t-case feeds back through the 4x4 control module, just like all the '02-ups. Just requires some wiring creativity to work around it (I think.... still haven't found anyone to let me try it). I'm also not sure how well the BWM would interface with the RSC programming either.... might take some creative aftermarket programming to work around this one....

-Joe