"Overdrive Off" switch?

[UltimateG]

So, I'd love to have a switch on the dash that disables 4th gear in my Jeep. Has anyone put one of these together? Is it possible to create one for a '94 aw4?

[drifto77]

Why not just do this and save some money?

.P
.R
.N
.D
.3 <---- position the shift lever here
1-2

[DurbElites]

:clap: always works for me.

[WB9YZU]

So, I'd love to have a switch on the dash that disables 4th gear in my Jeep. Has anyone put one of these together? Is it possible to create one for a '94 aw4?

Wow ! For real? You have to be shitting us !

Looks as though he needs to get his computer fixed as it's throwing ID10T errors :D

Just kiddng j/k Check out 3rd gear, that's what is there for.That would be the #3 on your shifter.

Here's how you get there.

1)Push the button on the left side of the shifter with your Thumb (*" while curling your hand over the "T" handle.
2)Pull the shifter one notch back from "D" untill the indicator lines up with "3".

* Note: On some newer models, you will need to dissengage the knob lock by touching the brake first.

[fizassist]

Questions you wish you'd never asked. ;)

[CommandoXJ96]

what would be nice is if there was a way to some how change the 1st position to just 1st, 3rd to 2nd gear, and add an O/D off/on toggle for use in Drive.

P > P
R > R
N > N
D > D (O/D Toggle)
3 > 2
12 > 1

I just think it would be a better shift arangement functionally. that 2nd gear is important too.

[drifto77]

So.. CommandoXJ96
you wanna have FULL control over the gears???
Check this out......

http://www.awshifting.com/

Contact BrettM
http://www.naxja.org/forum/member.php?u=31

[Matthew Currie]

Now before we jump all over this guy, maybe we should get a clarification of what he's really trying to accomplish.

Using the shifter is pretty obvious, but it depends a little on what results you're after. Shifting to 3 gives you 1-2-3 and torque converter lockup on 2 and 3. As far as I know, it does not change the shift points, but it does change the TC lockup pattern. In "D" it locks up in 3 and 4, rather than 2 and 3. If you want to change the TC lockup characteristics, this would require some kind of switch, though the obvious thing to switch would be the lockup solenoid rather than the shifting.

So, if UltimateG has not been embarrassed into total silence, how about it? Is there some effect you're after other than what you get with a downshift?

By the way, to disable fourth with a simple switch would be very difficult. The AW4 is controlled by a pair of solenoids, which determine the gear depending on their combination. The solenoid combination for fourth is "off-off." This means that whatever switch arrangement you use would require you to switch solenoid #2 back on when the TCU wants if off for fourth. But you could not simply hard-wire it on without losing first gear. So you'd need to switch on the fly and remember to unswitch every time you come to a stop. About the only mechanical solution would be wire a relay that turns solenoid #2 on when #1 goes off, but returns control to the TCU when #1 goes back on. And of course whatever relay you use would have to have sufficient impedance and isolation that it doesn't load the solenoid circuits or feed back. In other words, fuhgeddaboudit!

[langer1]

There is no 4th or overdrive just a full lockup converter is there?

[BrettM]

There is no 4th or overdrive just a full lockup converter is there?
does that make sense to anyone else?

And Matthew is right 2 posts up, also, the compression qualities change in the 3 position, providing the most compression braking in 2nd rather than in 3rd.

[CantonXJ]

I'd personally like to have a switch just to disable TC lockup.

Dave

[scoobyxj]

I'd personally like to have a switch just to disable TC lockup.

Dave
A good way to overheat your tranny.

[cal]

I'd personally like to have a switch just to disable TC lockup.

Dave


I had no tc-lockup for a while due to a wiring short.

now i have a new aw4.

don't do it. :)

[WB9YZU]

Now before we jump all over this guy, maybe we should get a clarification of what he's really trying to accomplish.

Nah, it was a dumb question ;) Probably moon related, there have been an awful lot of dumb questions floating around work lately also ;)

Using the shifter is pretty obvious, but it depends a little on what results you're after.

Don't over think this one. How one selects gears electronicly, modifies the TCM, or manually selects the TC is beyond the scope of this OEM forum.

[UltimateG]

Thanks a lot, ya bunch of wisea$$es! :D


Yes, you received my question correct. I’m such a fat, lazy bastard that I don’t like taking my hand all the way off of the wheel and reaching the entire 8 inches away to yank the shifter back into 3rd.

No, seriously. I didn’t realize just how much of a workout that really is until I drove my buddies Grand Cherokee yesterday. I discovered his WJ has a fancy little button by the steering wheel marked “o/d off”, and now I want one too. I live in the mountains, and drive steep, twisty passes to work every day. I really do appreciate the ability to switch to third gear without moving my hand from the steering wheel and taking my eyes off the road.


The funny story behind my learning about this button is that yesterday we were doing 60 mph and approaching a steep hill. Thinking his jeep was just like my xj, I grabbed the shifter and yanked it back. - after he bounced his head off the dashboard, he explained to me that I had just put it into second gear, and then pointed out that fancy little button to me.

I just assumed it would be easy, and all I’d need to do was wire a cutoff into a solenoid somewhere. Guess not, bummer.

Cheers.

[WB9YZU]

There is no 4th or overdrive just a full lockup converter is there?

3,900 posts and you don't know how many gears an AW4 has?
ROFLMAO! you crack me up ! Must be the moon !

[BrettM]

3,900 posts and you don't know how many gears an AW4 has?
ROFLMAO! you crack me up ! Must be the moon !
the 4 stands for "4 wheel drive" right?

[drifto77]

And if your on the freeway doing 70 and get passed by a ricer .... the "R" is for race. http://www.naxja.org/forum/images/icons/icon12.gif

[jeepdude10000]

ok if I read right, if you leave it in 3'rd the torque converter will still lockup.
I have actually tried this, and as far as I can tell it does no(at least on my XJ).
Am I doing something wrong?

And why is it so bad that the TC needs to lock?

[fizassist]

Bigotry is having one two many wife’s, and monogamy is the same!

(1) "Bigamy", not "Bigotry"

(2) "wives", not "wife's".

[Matthew Currie]

ok if I read right, if you leave it in 3'rd the torque converter will still lockup.
I have actually tried this, and as far as I can tell it does no(at least on my XJ).
Am I doing something wrong?

And why is it so bad that the TC needs to lock?

It's supposed to lock up in the top two gears. It's possible that it's locking in second and shifting locked. It's been some years since I had an automatic, but when I had my 87 AW4, it appeared that in OD it would shift from third to fourth without unlocking if you didn't push it too hard. Accelerating harder it would wait to lock until it was in fourth, and if you counted the shifts it would feel as if it had 5 speeds. Mine did not have a tachometer, so it was hard to judge exactly what happened when. Shifts were so smooth and seamless it was hard to keep track of them. My stepson had an automatic with a tach, but I never got a chance to play with it much (except of course when it was broken, then it was all mine...). If you have a tachometer, you might be able to distinguish locked from unlocked by how much the tach needle rises when you accelerate. If you do it hard enough to unlock (or if it's not locking at all), the needle will jump and then settle back. If it stays locked it should rise gradually and not drop back.

I don't think there's any disadvantage to locking up, except that unlocked you'll get a little more torque multiplication. I could see wanting it unlocked when wheeling. But theoretically, at least, it should run cooler with the TC locked, since there's no slippage in the TC. I think one of the main reasons for recommending downshifting under severe loads is to prevent it from continually unlocking and relocking under stress. Then again, automatic transmissions are kind of funny, and if some expert told me that it should run cooler with the TC unlocked, I'd say OK, just another one of those automatic anomalies. Anyway, if yours seems to be behaving, it's probably all right. They're pretty bombproof.

[87manche]

the TC is not meant to take full engine torque while it's locked, hence the unlocking before shifting if you hammer it.

[langer1]

3,900 posts and you don't know how many gears an AW4 has?
ROFLMAO! you crack me up ! Must be the moon !

The AW4 has 3 speeds + 1 in the TC makes 4
Sorry about that, not enough coffie, the overdrive is not in the TC

[lawsoncl]

The AW4 has 3 speeds + 1 in the TC makes 4
Sorry about that, not enough coffie, the overdrive is not in the TC

Um, the AW4 has 4 gears plus the locking torque converter.

1st Gear 2.80
2nd Gear 1.53
3rd Gear 1.00
4th Gear .75 or .70 depending on the year

[langer1]

Um, the AW4 has 4 gears plus the locking torque converter.

1st Gear 2.80
2nd Gear 1.53
3rd Gear 1.00
4th Gear .75 or .70 depending on the year

Thats what I meant in the correction.

[BrettM]

:confused1

[jeepdude10000]

Ok im going to see if it will lock up in 3rd.
My hole idea I was going for is that i read another thread that said they got better gas milage at the mid 2500 rpm range, I know I should not worry about getyting more mpg since my XJ already gets 21 mpg, but i would like to see better. So i am going to leave it in 3rd gear for a tank to see if i can get better milage.

[BrettM]

Ok im going to see if it will lock up in 3rd.
My hole idea I was going for is that i read another thread that said they got better gas milage at the mid 2500 rpm range, I know I should not worry about getyting more mpg since my XJ already gets 21 mpg, but i would like to see better. So i am going to leave it in 3rd gear for a tank to see if i can get better milage.
it depends on your gear ratio and tire size. if they're both stock you'll likely get your best mileage in 4th, but if you've put on larger tires without regearing it's very possible to get better highway mileage in 3rd.

my new MJ has 3.55s with small 215/70r15s and cruises 2200-2500 on the highway (I forget exact speeds), I haven't got through a whole tank yet, but it looks like it's going to be over 20mpg.

[jeepdude10000]

Mine has 265/75/15's and runs 1900 rpm at 70 mph.

[knottshawk]

Bigotry is having one two many wife’s, and monogamy is the same!
(1) "Bigamy", not "Bigotry"

(2) "wives", not "wife's".

I'd like to add this:

(3) "too", not "two"

[langer1]

Ok im going to see if it will lock up in 3rd.
My hole idea I was going for is that i read another thread that said they got better gas milage at the mid 2500 rpm range, I know I should not worry about getyting more mpg since my XJ already gets 21 mpg, but i would like to see better. So i am going to leave it in 3rd gear for a tank to see if i can get better milage.

This thread is confusing because some people are talking about TC lockup while others are talking about 4th gear (OD) the two are not the same thing.

The question was about (OD) and putting the shifter in third stops (OD) but not TC lockup.