What about AW4 mods

[Rock Yacht]

to handle a stroker? Planning ahead, the stroker is on the list todo this fall/winter (if the tired old 196K 4.0l hangs in there) Lots of good reading on the engine, not so much on the tranny. Or am I just looking in the wrong places?

Bob

 

[BrettM]

that's because the tranny doesn't need any help. maybe if you were stroking and supercharging, but definitely no problems with just one or the other. The AW4 is rated for 400hp.

no matter how much power your 4.0 is putting out, a tranny cooler should be considered a must if you wheel it.

 

[Rock Yacht]

Thanks Brett, there's got to be something you can tweak a long as you are in there, sorry not the type to just leave well enough alone...

Bob

 

[BrettM]

I've heard http://www.levelten.com/ does some cool stuff with the Supra version of the tranny for those guys running 600+hp.

The AW4 in stock form is very strong and very reliable, the only thing I could think to change would be a different stall-speed on the torque convertor, but for rock-crawling/trail-riding the stock (~2100) stall speed is perfect. If you're interested in more drag/street performance I sold one of my AWshifters to a guy who does dirt drags with his and just finished a turbo. I could probably get you in touch with him, I know he did a little tweeking to his TV cable for firmer shifts, which may or may not reduce the longevity of the tranny.

 

[JJacobs]

The AW4 is rated for 400hp.

Where'd you get that number? I'd think a trans would be rated for torque, not HP.

 

[BrettM]

Yeah, I know what you mean. Honestly, I don't remember the original source, but from what I've seen both in the Supra crowd and the forced induction and/or stroker Jeep crowd this seems to be an accurate number.

 

[XJZ]

Since we're on the subject.......

Does anyone know the strength difference between a 21-spline AW4 vs. a 23-spline.

I'm curious because I have an '89 21-spliner and hope to stroke sometime down the road. It's only a couple splines, but the shaft on the 23 spline is substantially thicker.

Might be best to get a 23 spline AW4 just to be sure, but would be nice to not have to swap it either.

What do you guys think?

 

[BrettM]

i would consider it almost a non-issue as far as strength. However I would get the 23 spline just for the ability to run so many more t-cases.

When I did my AW4 swap I could have got several 21 spline units for free, but I held out and got a 94 for $150 for the better (for me) overdrive ratio and the ability to easily run a D300 if I go that route in the future.

 

[XJZ]

I'm set as far as t-cases go. But will swap input shafts if I feel it's needed.

I've never heard of any one breaking a 21 spline tranny shaft, but who knows for sure?

In Advance Adapters literature they say "The 21 splines on these transmissions are very small in diameter, and thus we have seen the stock output shaft break on many engine converted vehicles."

Is a stroker the equivilent of an engine conversion? A pump-gas 4.6 stroker will put out 300 h.p. max and I would guess these engine conversions are small block V-8's putting out closer to 400 h.p. or more. Where's that line? :dunno:

Also, I'm not going to be burning rubber with this thing. I just want the extra h.p to make-up for the loss of h.p. larger tires take and get over the mountain passes with less effort (Well actually, to kick everyone's butt getting over the pass ).

 

[BrettM]

i would think you would blow apart an np231 before a 21 spline output shaft. you didn't go and convert a D300 or Atlas to 21 spline did you?

 

[XJZ]

i would think you would blow apart an np231 before a 21 spline output shaft. you didn't go and convert a D300 or Atlas to 21 spline did you?

Uummmm, sort of. I'm keeping that under wraps 'til this fall.

 

[Ed A. Stevens]

IIRC, the 23 spline shaft is only about 0.090" larger in dimeter than the 21 spline shaft. The 23 does fit more standard T-cases.