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Everything you ever wanted to know about the AW4

Really harsh shifting at low throttle.
Lol alright, that's on me.

Will shifting at max pressure all the time cause damage?
Will the trans being told to operate at max pressure cause damage?
Will the trans being told to operate at max pressure cause temp issues?
Will the clutch pack wear quicker or slower due to more aggressive engagement?
When sitting at a stop does the clutch try to slip at all or is the entirety of the slipping performed by the torque converter?
Are the different pressures for reverse and drive managed internally?
 
What is the way to find if my 1990 XJ has a 0.75 or the 0.705 OD ratio without counting output splines? Can this be found by VIN or a serial number on the AW4, or other marking?
 
What is the way to find if my 1990 XJ has a 0.75 or the 0.705 OD ratio without counting output splines? Can this be found by VIN or a serial number on the AW4, or other marking?
Why do you care? The difference at freeway speeds is only 100 rpm!
 
705/750 OD gear difference is about 6% change I am thinking of regearing for 35" tires or to make my 33" tired jeep better as it has 4.11 gears now.
my choices are 4.56 or 4.88 gears 456/488 is about a 7% change. If I got a 70.5 OD gear then the 4.88 gear will be not as buzzy a choice for freeway use, if I use a 4.56 and have have a .75 OD ratio, I will have a very similar highway OD final ratio as the prior example. A combination of of a .75 OD and 4.88 axle may make the rig a bit too buzzy for highway cruise in OD gear, I want to calculate the final ratio.

I do have an Atlas 4.1 low range transfercase so my main concern between the two axle ratio choices is highway travel, rather than off road performance. oft we have several 100's of miles travel on highway to get to wheeling areas

As it is now with my 33 tires and 4.11 axles, I find my rig needing to down shift at 65 mph for even minor upgrades, and for steeper high altitude upgrades in the Seirra's I even drop into 2nd or even first once and a while on steep paved roads. Hills on Interstate 5 heading from San Jose to death valley make me down shift prematurely

Now my buddy has a 2001 XJ, so he has the .75 OD, 4.11 axles, and 32 tires he and me are planning on trying to do the same tire size and final drive ratio for highway use as we oft travel in convoy, but I find I am slower do to having to prematurely down shift on grades compaired to him. He has the H.O. 6 cylinder, so he has a few money ponies under his hood than me. I have the Renix. If I do indeed have a .705 OD and if he gets the 4.56 axle, then to be closer to his valve I should get the 4.88 axle in my rig, if however I have a .75 OD then me and him both should get same axle ratio.

So how can one tell the OD ratio other than counting splines or gear teeth? Is there a serial number of VIN that will tell me, a stamp on the transmission case?
 
one more thing...

conflicting info on OD ratio...
"Pre-1991 (non-HO Jeeps) AW transmissions had 21-spline output shafts. 1991 and later units have 21-spline output shafts. At some point, the AW changed from a 0.79 4th gear ratio to a 0.75 4th gear ratio - possibly also in 1991. "

was the early OD .705 or .79? early in this thread Naxja say it was .705 but above link says .79 and of course above link got a typo with the spline count I assume ugh!!

Please see my prior post on aw4 OD identification
 
Supposedly the spline count and final gear ratio changed along with the HO engine in 91, but that's also not a guarantee they weren't still installing old stock transmissions.

3rd gear is 1:1 for both versions. Early AW4 21-splines were 0.705, and later 23-spline are 0.75. To figure out which you have, compare the engine rpm at the same speed in either 3rd or 4th gear with the t/c locked up. It's only going to be about 200 rpm difference at 3000 rpm.
 
I have a 88 MJ with a 4.6l stroker AW4 trans 231 transfer case. I am running it on a 2004 Vortec 4.3l V6 computer system. I need to get rid of the Renix TPS so I can run the GM TPS.
The only thing I can come up with is to go to a 91+ AW4 and run a matching TCU.
Will the 91+ TCU plug up an work on my 88 wiring harness?
Basically what I need is a stand alone AW4.
I'm still using the Renix wiring to run the dash/trans.
 
You don't need to swap the AW4. It should work with a 91-97 TCU, and a TPS signal that runs 0->5 volts instead of the Renix TPS which ran 5->0 volts. The TCU will plug into your harness, but you will have to shave off the raised notch on the wiring harness connector. The data lines changed along the way, but you're not planning to use them and the Renix data lines just went to the yellow diag connector. The difference in the AW4 gear ratios won't be an issue. I'm running a 98 AW4 with a 89 TCU.

How are you handling the throttle body? Are you not able to use the dual output TPS sensor for the Vortec computer? You still need the throttle body to trans cable to control the shift pressure.
 
You don't need to swap the AW4. It should work with a 91-97 TCU, and a TPS signal that runs 0->5 volts instead of the Renix TPS which ran 5->0 volts. The TCU will plug into your harness, but you will have to shave off the raised notch on the wiring harness connector. The data lines changed along the way, but you're not planning to use them and the Renix data lines just went to the yellow diag connector. The difference in the AW4 gear ratios won't be an issue. I'm running a 98 AW4 with a 89 TCU.

How are you handling the throttle body? Are you not able to use the dual output TPS sensor for the Vortec computer? You still need the throttle body to trans cable to control the shift pressure.
I'm using the GM throttle body, it measures 71.73mm I've bored the intake to 66.70 and made a adaptor for a smooth transition between them.
I can tap the GM harness for the 0-5v signal.
I have the trans cable mounted already.
 
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