Selec-Trac With Automatic Transmission Only!?

[NextStep9]

01-06-18 Disappointed! Jeep must be kidding!? Last week, in the Jeep online configurator, the "Selec-Trac Full Time 4WD System" option was available with the manual transmission! Today, unfortunately, it is only available with the automatic transmission. Is this correct!?

Sponsored

 

[ThirtyOne]

Yes. It has been correct all along and was just a mistake in the configurator.

 

[Hughesonthenet]

Does anyone know if there is a technical reason that selectrac requires an automatic transmission, or is it just an arbitrary decision by those that make such decisions?

 

[digitalbliss]

Does anyone know if there is a technical reason that selectrac requires an automatic transmission, or is it just an arbitrary decision by those that make such decisions?

Probably has to do with programming the ECU and TCM to work in conjunction of the computer controlled 4 auto. Think about it. The 4 auto is computer controlled. If you have an AT that is also computer controlled, it allows you to program the auto 4 (AWD) and transmission in conjunction to change power delivery, torque, front/rear ratio as needed.

I would be curious to know if there is any modern computer controlled awd/4wd system that offers a MT as an option.

 

[zogby]

This is disappointing news. I recall seeing some order sheet in the past that indicating that SelecTrac and MTs weren't compatible, but the online configurator kept allowing it, so I had some hope.

Since this makes SelecTrac less desirable for me, the pendulum swings back toward the Rubicon again. Who knows where it'll end up.

 

[Jeepsterfreak]

It also forces the $595 LSD option and $895 wheel upgrade on the configurator. I've read the wheel option is an error, not sure about the LSD.

 

[ThirtyOne]

The Order Guide and the Dealer Guy confirms that LSD is required with Selec-Trac. LSD is also required right now for manual transmission on Sport and Sahara.

Wheel upgrade is not required.

 

[ResponsibleAdult]

Probably has to do with programming the ECU and TCM to work in conjunction of the computer controlled 4 auto. Think about it. The 4 auto is computer controlled. If you have an AT that is also computer controlled, it allows you to program the auto 4 (AWD) and transmission in conjunction to change power delivery, torque, front/rear ratio as needed.

I would be curious to know if there is any modern computer controlled awd/4wd system that offers a MT as an option.

Subaru pairs manuals with awd

 

[nel1551]

The Order Guide and the Dealer Guy confirms that LSD is required with Selec-Trac. LSD is also required right now for manual transmission on Sport and Sahara.

Wheel upgrade is not required.

Wheel upgrade is not required. Just ordered without the wheel upgrade but have selectrac. Lsd is required with selectrac

 

[Jimbobcooter]

Probably has to do with programming the ECU and TCM to work in conjunction of the computer controlled 4 auto. Think about it. The 4 auto is computer controlled. If you have an AT that is also computer controlled, it allows you to program the auto 4 (AWD) and transmission in conjunction to change power delivery, torque, front/rear ratio as needed.

I would be curious to know if there is any modern computer controlled awd/4wd system that offers a MT as an option.

Subaru and Audi have AWD and manual transmissions.

 

[digitalbliss]

Subaru pairs manuals with awd

Subaru and Audi have AWD and manual transmissions.

Yes, Subaru does pair AWD with manual transmissions, but these version of AWD are not the same as their most modern computer controlled variants.

The first system is the Viscous Center Differential. It uses a straightforward 50/50 torque split with open front and rear differentials. This system is used only on Subaru models with a manual transmission, save for the WRX and WRX STI.

Found in most of Subaru's vehicles equipped with a manual transmission, the system that we'll call "standard" for simplicity's sake is the most symmetrical of the configurations defaulting to a 50:50 torque split under normal, no-slip driving conditions.

When slip on the front or rear axle is detected, a locking center differential is able to send up to 80 percent of available torque to the axle that has the best traction. The center differential uses a viscous coupling that operates without the aid of computer control and reacts to the mechanical differences in grip.

The second is likely the one most consumers will be acquainted with: the Active Torque Split system. It's found on all CVT-equipped Subaru cars minus the WRX and features a 60/40 torque split. The clutch pack found in the all-wheel-drive system is designed to allow for some slip, but if traction begins to falter on a certain axle, the system locks the clutch pack, applies more pressure, and sends more torque to the wheels that need it.

What makes the second system "active" is the fact the system communicates with other vehicle sensors to understand if a situation requires more torque at a certain wheel.

 

[ResponsibleAdult]

Yes, Subaru does pair AWD with manual transmissions, but these version of AWD are not the same as their most modern computer controlled variants. .

Can you delve deeper into this for me? Why can't the AWD that they have on their CVT be paired with their manual, and then why can't Selectrac be paired with a manual?

I appreciate you taking the time to explain this. Thanks

 

[digitalbliss]

Can you delve deeper into this for me? Why can't the AWD that they have on their CVT be paired with their manual, and then why can't Selectrac be paired with a manual?

I appreciate you taking the time to explain this. Thanks

I'm not an expert by any means, i'm just a guy who is familiar enough with some of these things to be dangerous! haha
With that being said, I'm not sure that they CANT do it. I just think that the optimal results will be from an auto trans (cvt in the subies) and the computer controlled AWD systems. A computer controlled system is able to control the torque bias at each axle via a cluch pack to send power front and rear, and at each wheel using individual wheel braking. This system decides what to do based upon sensors (usually the abs system). With a computer controlled transmission, the AWD system is able to change these variations in a more controlled and predictable manner. To cut power or increase it, the trans can shift into other gears when the computer wants/needs it to. If it is a MT, then there is no way it can decide what to do.

 

[MojitoJLUR]

Yes, Subaru does pair AWD with manual transmissions, but these version of AWD are not the same as their most modern computer controlled variants.

The first system is the Viscous Center Differential. It uses a straightforward 50/50 torque split with open front and rear differentials. This system is used only on Subaru models with a manual transmission, save for the WRX and WRX STI.

Found in most of Subaru's vehicles equipped with a manual transmission, the system that we'll call "standard" for simplicity's sake is the most symmetrical of the configurations defaulting to a 50:50 torque split under normal, no-slip driving conditions.

When slip on the front or rear axle is detected, a locking center differential is able to send up to 80 percent of available torque to the axle that has the best traction. The center differential uses a viscous coupling that operates without the aid of computer control and reacts to the mechanical differences in grip.

The second is likely the one most consumers will be acquainted with: the Active Torque Split system. It's found on all CVT-equipped Subaru cars minus the WRX and features a 60/40 torque split. The clutch pack found in the all-wheel-drive system is designed to allow for some slip, but if traction begins to falter on a certain axle, the system locks the clutch pack, applies more pressure, and sends more torque to the wheels that need it.

What makes the second system "active" is the fact the system communicates with other vehicle sensors to understand if a situation requires more torque at a certain wheel.

This guy is spot on. I used to work at our division that makes the Jeep transfer cases, but now I'm in electronics.

 

[ThirtyOne]

Quite apart from the engineering, it probably just doesn't make sense from a market perspective. The manual is only 20 percent of sales now. And with the introduction of the Diesel and Turbo it may go down. And with the Sahara being the luxury 4-door SUV it isn't really being positioned for the manual. So it probably just makes sense to offer the Selec-Trac on Sahara with automatic.

Sponsored