Went to TSF last weekend for a bit of wheeling, and to check up on our chapter's adopted trail, Saddle Up. Wheeling was meh, Saddle Up looked awesome, and the Nail Salon did awesome.
Lately though I've been getting slightly annoyed with the AW4's shifting. Mainly the whole not being able to hold second off-road, and lack of compression braking. Holding it in 1-2 is too slow, and 3 is too fast.
The answer to this problem comes in the form of Rory at RADesign's,
Rail II Shifter. The Rail allows for full manual control of the AW4, while also allowing you to keep the TCU and have it shift normally. After putting purchasing one of these since day one of owning an auto, I finally ordered one up after returning home from TSF.
A few days later I had a package waiting for me.
The Rail II is a slick little unit all aluminum CNC machined.
In addition to the Rail Shifter you'll also need some switches. One On-On three terminal to control the torque converter, and one On-On six terminal to control the Rail/TCU mode.
Thank you RedJeep2.0 for the #'s.
On-On DPDT Three Terminal NAPA#6261
On-On DPDT Six Terminal NAPA#6064
With all the parts needed for install I got to work mounting the switches and Rail.
The next step is locating the appropriate wires needed spliced. On the OBDII XJ's the transmission control unit (TCU) is located above the gas pedal under the dash.
Locate these wires on the TCU harness, and then proceed to cut them in two.
Solenoid #1 - White
Solenoid #2 - Orange w/white stripe
Torque Converter - Dark blue w/white strip
With the wires separated in two (one side coming from the TCU and the other going to the transmission) add the appropriate length wires to reach your switches. I had some red and green 18ga wire on hand so red would be
from the TCU, and green would be
to the trans. Just to ease with confusion I labeled the wires too during the wiring process. Also use some zip-ties or electrical tape to keep the loom neat and tidy.
Here's how I wired my torque converter control switch.
Post 1 - 12V (I spliced into the cigarette lighter power wire which is hot when keyed on)
Post 2 - To transmission
Post 3 - From TCU
So basically when the switch is flipped for 12V the torque converter will lock up, flip it again and it functions automatically.
The six post switch is for selecting between having the Rail control shifting or the TCU (normal). It wires similar to the torque converter switch. The two terminals on one side are from the TCU (solenoid 1 and 2 wires), the other side are the yellow and blue wires from the rail, and the center terminals are for the solenoid wires going
to the trans.
Left side of switch - blue rail wire, solenoid 1 to trans, solenoid 1 from TCU
Right side of switch - yellow rail wire, solenoid 2 to trans, solenoid 2 from TCU
The last step is giving the Rail power via the red wire. Find a keyed 12V source.
Interior all buttoned up, and ready for a test drive.
Rail is easily within arms reach, and the e-brake is still semi-easy to grab.
Some helpful advice for operating the rail.
stuoffroad said:
Manual Control:
(AW-4 transmission shifter position is noted first in each line)
DRIVE position: not true manual control during compression braking as transmission still wants to shift "out". This is just fine as long as you are on level ground (or going up a hill, ledge, etc...) and not descending a steep ledge or grade in low range.
1 - 2 position: transmission will lock in 1st or 2nd gear and compression braking is now possible.
3 position: transmission can be shifted between 1st, 2nd and 3rd. Don't expect the transmission to stay in 1st gear
REVERSE: operates normally
I don't have a ton of time using it yet, but it does exactly what I want it to. I can hold second gear, and using the engines compression on descents. The torque converter lock-up switch will be handy to have on road trips. Thanks Rory, for offering a great product. I already regret not getting one sooner.
Now to test it out on the trail.
