JEEPERDK

has anyone seen or heard of this little wiring trick to make it so you can manually unlock and lock your torque converter and also have the ability to manually shift your AW4 into and out of the 1 and 2 second gear position?


when I was reading the thread it did say it would throw a code in the 97+ XJs. im not to worried about it as I wouldn't be using this mod very often, only when I go wheeling. I plan to do this on my 01 XJ just to try it and im also thinking of combining it with a tansgo shift kit as well.


thoughts on this little trick?


http://articles.jeepforum.com/XJ_AW4_TCU_Shift_Mod


Thanks for any thoughts and advice ahead of time!

CobraMarty

Do you know why you want to do this? What are you looking for?


The transgo kit has the option of keeping trans in 1st gear when lever is in 1-2.
Why do you want to lock the TC? Quick way to burn it out as it is not very strong.

andrewmp6

You can buy a switch shifter http://www.radesignsproducts.com/Rail.html or 175 bucks a new shifter http://www.radesignsproducts.com/RockShifter.html

JEEPERDK

I would like to do this for off roading purpose. Holding the tranny in first gear is what you want wyen offroading as it gives you the most torque multiplacation. But with the aw4 not having that option there is always the possibly of blowing the transfercase when a quick shift from first to second happens when in 4low and looking for some wheel speed. The transgo shift kit will only be used to get a firmer quicker shifting tranny. After all heat kills 90% of auto transmissions. Heat is caused by friction that is encountered during soft slow shifts. Thats not what you want when offroading unless you like replacing transmissions, which I dont. I already have to do that every week during the summer with my fathers race car.

Locking and unlocking the torque converter will help for better gas millage. This vehicle is my daily driver so getting the best millage possible is nice. This will help when crusing at highway speeds or in village speeds where there is no need for lots of torque multiplacation. Plus when trailing being able to lock the converter gives you nice downhill engine braking along with having a wider variety of torque multiplacation ratios between the different gears.

I like the ra designs shifters but the rail I would never use for a daily, nice for trail rigs but I feel it would be a pain when it comes to daily driving. I would get a new shifter all together but being that im a part time working 17 year old in highschool still im looking for some cheaper alternatives to manually control my aw4

CobraMarty

The Transgo kit works really well. I have 2. Firms the shifts and slightly quickens the shifts on the 'truck' setting. The 1st gear option is just what you are asking for. With the gear lever in 1-2, the trans will stay in 1st gear and not shift into 2nd.

You will only get trans 'coupling' not freewheeling when going downhill if the lever is in a position of the gear you want or 1 gear higher. In D there will be no trans decal coupling in 1st or 2nd gear. You will need to move the lever into 1-2 to get decal coupling in 1st or 2nd. 3 position will get coupling in 2nd gear and not 1st.

This decel coupling is different than TC lockup.

For economy, the trans does very well shifting and going into TC lockup as soon as it can. There is no need to manually do TC lockup while on the street.

On your '01 there will be CELs with the switch method unless you get fance and use some resistors.

For daily driving, the transgo kit is about the best.
I have a modified TCU which will give you everything you want, no TC manual lockup, and only uses 1 switch, manual-auto, and the rest is done with the shift lever. 1-2 is now 1st gear, 3 position is 2nd gear, D is 3rd gear. It is a bit expensive, $200 for a modified TCU.

JEEPERDK

cobramarty, do you have a indepth write up on how you did the modified TCU? i remember reading your write up somewhere over on naxja i think but i cant seem to find it any more. i would like to see how you went about it with your switch controlled manual shifting.




also how exactly does the trangos shift kit make it so the tranny stays in 1st gear and then allows you to shift into second? im not understanding how that would work.

CobraMarty

Yeah the transgo kit you have the option to ?change a plunger or drill a hole and it will do this 1st gear hold in 1-2. When you move lever to 3 it will then shift into 2nd or 3rd.

I add a relay board, diodes and resistors and cut and splice into the stock TCU and it all lives inside the TCU box. It just plugs into where the stock TCU plugs in and you remove/replace the stock TCU. All that comes out is one wire which goes to a switch and then to ground. With the wire grounded, my 'piggy back' board takes over and you shift manually with the stock stick. Switch off and it is back to normal auto shifting.

Fred/N0AZZ

I have thought about this post for 3 days now and can't see the reason's for this mod being done on the AW4 where any real benefit would be gained.

I have been using manually shifted auto transmissions since the mid 60's first behind the Dodge Hemi's and the last 25 yrs. T-400's and Powerglides from GM.

For any manual shifted auto trans to work very well it must be rebuilt with a manual valve body along with things, then coupled with a custom converter built for a specific job. I have no idea on how much a converter would be for an XJ but my last one for the twin turbo motor was a Hughs and cost $2300 the one before a N2o motor was $1700. My last trans came from NY City and cost $3175 for a T-400 rated at 2000HP (still to be fully tested).

It seems that at the very least for it to work properly that it would cost more than a few bucks and a trans shop would have to go through the trans for a prep. I just can't see the investment for the return but JMHO

MontanaXJer

Montana Fab Trans Override

Simple, proven, effective. All with no "check engine" light.

NAXJA thread: http://www.naxja.org/forum/showthread.php?t=1010278

CobraMarty

I guess it is all about control.
In 1-2 position it will shift between 1st and 2nd. On our autocross xj we need to be able to control the gear. Off road mostly to prevent 2nd gear upshift.

windlover

I did the mod and love it. I set mine up as a first gear lockout.


I hate having it shift to first when I am in 4LO, its like slamming on the brakes.

JEEPERDK

thank you for all the info guys. I guess im going to have to consider my options. im already planning on dropping the $90+ on the transgo shift kit. I like this mod as its cheap (only the cost of switches, some wire, and maybe some small LEDs for looks) and it still gives me the benefits im looking for.


the montana fab switch is nice and I probly would buy it but I just cant justify the $166 for a switch and a small circuit board.

RWKHausSupply

Keep in min that if the manual cable shifter is more than 1 gear different than the electronic "switch" then there will be no engine braking.

CobraMarty

^^ That exactly.

JEEPERDK

can you explain a little more? sorry Im not very familiar with AW trannys or the electronics in the trannys themselves for that matter. I came from a background of drag racing mopar products, so the only auto trannys im really familiar to working with are the torqueflights.