Manual or automatic?

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I thought I knew that AX15s had poor ratio choices, so do some research. They are not a particularly strong gearbox. I'd go Mopar A833 OD before I did that
The ratios are: 3.83, 2.33, 1.44, 1.00, 0.79.
It's geared low in first to be used as a truck transmission. I've heard different things about it's ability to handle abuse in different applications. It seems to hold up pretty good in Dakota's and Jeeps, but not so well as the AR 5 GM variant in Colorados that have been LS swapped making over 300 HP. The Toyota R154 seems to hold up to turbo 2JZ's.
 
The ratios are: 3.83, 2.33, 1.44, 1.00, 0.79.
It's geared low in first to be used as a truck transmission. I've heard different things about it's ability to handle abuse in different applications. It seems to hold up pretty good in Dakota's and Jeeps, but not so well as the AR 5 GM variant in Colorados that have been LS swapped making over 300 HP. The Toyota R154 seems to hold up to turbo 2JZ's.
Nice thing is, the AX-15 and R154 share the same trans to bellhousing pattern, so if you swap in the AX and later find a decent deal on an R154 (they’re stupid expensive compared to the AX) it’s a direct swap.
 
In the end, only two things matter;
1) that you can put down a decent amount of torque, at the roadspeed you need it to be at. and
2) that the car cruises at an rpm that you can live with.

These two together conspire to either require an overdrive, or a stupid high hiway gear.
A close ratio is nice, but you can only make use of it, if the circumstances are right. and, you can overcome that with torque.

The truth is that a hi-stall convertor with a 4-speed auto and performance gears will satisfy every streeter's needs; crappy splits or not.
Whereas a Mopar 4-speed plus GVod will not satisfy, unless your engine has gobs of midrange torque, which with an SBM, you can only get with very high Cylinder Pressure, and then it will be crazy fun, with the right rear gear.
But you still run into the issue of having the right amount of torque at the right roadspeed.

To that end, for most of us streeters, Second gear is where it's at.
If you need power at 35 mph, yur gunna need the ratios to be just right, and you can get away with just torque multiplication. But
If you need it at 45mph, now you'll also need some serious actual engine torque

Finally, I have not ever tested a 5-speed manual, but manuals suffer from one fatal handicap, the loss of the convertor means no torque-multiplication from it, which takes you back to the rear end having to be increased in compensation.......... which is fine until it negatively affects your cruise rpm.

Don't get me wrong, I've been a stick man since 1970. And I have managed to try just about every combo possible of gear ratios, with a sbm. and I know exactly what my combos like, when it comes to torque-multiplication. So, I'm a happy guy. But, my engine with a cam like yours, put out about 195psi.
When I changed cams, the pressure dropped to 187, and all the fun went away. It took me all summer to get it back, and it ended with a different transmission and gears. and that was just ONE cam size from the same manufacturer! So I know how easy it is to screw up a combo, when you have a manual trans.

Here's the automatic thing.
Your cam probably peaks around 5000/5200, or should if it had adequate cylinder pressure. and that means, it's gunna torque peak around 3500 .
For me, I always gear the car to be at shift-rpm at the Top of Second at 60mph. Thus I can run thru the power-peak twice and still be under the speed limit..
For a power peak of 5000, you might shift that at say 5400. To get 60mph, at 8% slip, in 1.45 Second gear, you would need a rear gear of 4.56s, with 28" tires. You see the problem right. You need an overdrive. But even then, are you gunna run 4.56s on the street? You may have heating issues, like boiling away your gearoil.

Lets see what happens in First gear. 5400 in 2.45 first will get you to 37mph and on the shift, the Rs drop to 3200. You got torque down there? Well maybe you do, but will it be enough? But worse is, what happens if yur at 35mph, in Second gear just tooling along , minding your own business...... and you suddenly get the urge to hit the gas.
Consider what's about to happen .
You were at 2780. If the trans does NOT kickdown, that will increase to ~3000. Got torque?
But if she backshifts to first, the Rs will scream to 5070, and then she'll upshift in about a second and drop to 2990, got torque?
And listen, this is with 4.56s and 28"tires.
Thus you see that this combo will never be very satisfying, except it cruses at 65=2450, in .69od.
Or will it.

In the above scenario, the convertor stall is let's say stock.
But lets say your engine torque-peaks at 3500, so you get a 3500 stall. Now, your minimum rpm at WOT is gunna be close to that, so then, that's as good as it gets.
But now those 4.56s are all wrong for first gear, but if you change them, Second gear will get choked.
The point is, of course, to gear the car to torque peak at or near the speed you travel at, for most of the time, and let the other gears be what they will be.

Not so
with a nice tight 5-speed manual, or as in my case, using the GearVender as a gear splitter, behind the Commando 4-speed..It has a ratio of .78, which is about a close as you'll ever find.
With the right trans, in front of it, you can keep your engine on the pipe all thru the Eighth mile. which means that you can run a smaller engine or a smaller cam, and still have gobs of fun.

Choosing a manual or a stick, for the street, is kindof a personal thing.
Some guys are born to clutch, and some to not, and some just like what they like.
If I had money, I'd have a 5speed auto with a clutch.
 
i agree if you go to the trouble of fitting an Aisin Warner box go with the R154 from the toyota supra turbo... if you can find one

slant 6 or 273 use a W58 easier to find and cost less, preferably the later style with the steel sandwich plate looks rusty at the mid plate not grey like tha alloy sandwich plate version
W57 and W59 are same box with not so good ratios W59 in 2WD is a pickup tuck box but many hilux/4 runners were 4WD so used this with a transfer box on the back
W57 used in lotus excel

Aisin Warner.... something to do with BorgWarner and toyota. for toyota trucks and cars from mid70s onwards

you can squeeze the ancient steel case w50 from a 1976 celica in without cutting the cross member if you are happy to have a slightly off alignment with the diff but it was designed to be behind a 1600CC motor with 70 HP...still very strong for what it is/was given its size but a 318 would kill it eventually....find one.... all got swapped into british sports cars of the 1960s

Dave
I've seen R154's and W58's for sale for reasonable prices. They're both better options ratio wise.
The R154 ratios are
First Gear: 3.251:1
Second Gear: 1.955:1
Third Gear: 1.310:1
Fourth Gear: 1.00:1
Fifth Gear: 0.753:1
And the W58 ratios are
First Gear: 3.285:1
Second Gear: 1.894:1
Third Gear: 1.275:1
Fourth Gear: 1.00:1
Fifth Gear: 0.783:10
My car has a mild 318 Magnum probably making around 250 horsepower. I think most versions of this transmission would hold up behind it. If it was a slant six or made less power, the W50 might be a good choice for clearance.
 
It'll last forever behind a 5.2 in a street car. @75slant6 has had one behind a 5.9 for years and drives it hard, I think it's still holding up?

They were designed and put together better than an A833OD that's for sure. I had an AX-15 behind a 4.0L in a Cherokee, I beat on it hard doing plenty of speed shifting and it still worked great when the car got totaled with 250k on the odo.

I'd swap one in with the 2.76 gears and not look back. Idk if you can get gears that tall for a Ford 8.8 but 3.0x would still work well. I think stock SN95 Mustang GT auto ratio was 3.08?
From what I've heard they're good transmissions. I've seen 2.76 and 3.08 gear sets for sale in the $30-50 range, so they can be found.
 
Of those 3 options, I’d definitely do the AX-15 swap, unless you WANT an automatic, then I’d do the 46re. Like MopaR&D said, I’ve been running an AX behind a 5.9 magnum in my Duster for 10 years and 25k+ miles without the first problem. I currently have the car apart for a bigger cam, aluminum heads and efi but the AX will definitely be going back in. I originally had 3.23’s but 1st gear was useless other than starting off on a hill so I switched to 2.76’s. I plan to change my rear tires from 25.5” tall to 27-28” tall in the near future, so if I had it to do over, I’d do 2.94’s.
I was kind of back and forth whether I wanted to keep it automatic or not. It would be easier to drive as a cruiser, but not as much fun as a manual. Both transmissions would require the same amount of fabrication. This is probably going to be a winter project, so it can be apart in the garage for a while.
 
I run a 727 but it's pushbutton and they don't use a normal tailshaft :( And i was wondering earlier today why mopar used such long tailshafts on trains.. help not have super long driveshaft?

And.... if i could easily convert my car to a 5-6 speed i would do it in a heartbeat... could keep the 4.30s and still drive nice.. i have spent the last hour thinking bout if i wanna drop to 3.23 or 3.55... will be less fun but less annoying
I didn't know the push button transmissions used a different tail shaft. I'm not sure why Chrysler used such long tail shafts. I'm sure there's a reason for it.
The gearing is a compromise, and that's where I'm at. Have decent acceleration, or have something that can be driven on the highway.
 

Long driveshafts are bad. The longer that they get, the more balance becomes critical and then that limits drive shaft speed. That's why you got be careful switching to overdrive and crazy steep gears, the driveshaft speed has to taken into consideration.

That's why box trucks and the like have 3 and 4 piece driveshafts with multiple support points.
That's interesting. Thanks for explaining this.
 
I didn't know the push button transmissions used a different tail shaft. I'm not sure why Chrysler used such long tail shafts. I'm sure there's a reason for it.
The gearing is a compromise, and that's where I'm at. Have decent acceleration, or have something that can be driven on the highway.
yup.. and just so ya know.. Early 727s didn't use a normal driveshaft.. they had a flange it bolted to(bottom pic) and a provision for the park cable.. (2 cables, 1 to shift, 1 to park) you can see it here..
Only the 1965 had a slip yoke and cable provision... i'm trying to find a spare right now.. they are very hard to find.. i drove 12 hours to get the one in my car...
1758290573689.jpeg

1758290463124.jpeg
 
In the end, only two things matter;
1) that you can put down a decent amount of torque, at the roadspeed you need it to be at. and
2) that the car cruises at an rpm that you can live with.

These two together conspire to either require an overdrive, or a stupid high hiway gear.
A close ratio is nice, but you can only make use of it, if the circumstances are right. and, you can overcome that with torque.

The truth is that a hi-stall convertor with a 4-speed auto and performance gears will satisfy every streeter's needs; crappy splits or not.
Whereas a Mopar 4-speed plus GVod will not satisfy, unless your engine has gobs of midrange torque, which with an SBM, you can only get with very high Cylinder Pressure, and then it will be crazy fun, with the right rear gear.
But you still run into the issue of having the right amount of torque at the right roadspeed.

To that end, for most of us streeters, Second gear is where it's at.
If you need power at 35 mph, yur gunna need the ratios to be just right, and you can get away with just torque multiplication. But
If you need it at 45mph, now you'll also need some serious actual engine torque

Finally, I have not ever tested a 5-speed manual, but manuals suffer from one fatal handicap, the loss of the convertor means no torque-multiplication from it, which takes you back to the rear end having to be increased in compensation.......... which is fine until it negatively affects your cruise rpm.

Don't get me wrong, I've been a stick man since 1970. And I have managed to try just about every combo possible of gear ratios, with a sbm. and I know exactly what my combos like, when it comes to torque-multiplication. So, I'm a happy guy. But, my engine with a cam like yours, put out about 195psi.
When I changed cams, the pressure dropped to 187, and all the fun went away. It took me all summer to get it back, and it ended with a different transmission and gears. and that was just ONE cam size from the same manufacturer! So I know how easy it is to screw up a combo, when you have a manual trans.

Here's the automatic thing.
Your cam probably peaks around 5000/5200, or should if it had adequate cylinder pressure. and that means, it's gunna torque peak around 3500 .
For me, I always gear the car to be at shift-rpm at the Top of Second at 60mph. Thus I can run thru the power-peak twice and still be under the speed limit..
For a power peak of 5000, you might shift that at say 5400. To get 60mph, at 8% slip, in 1.45 Second gear, you would need a rear gear of 4.56s, with 28" tires. You see the problem right. You need an overdrive. But even then, are you gunna run 4.56s on the street? You may have heating issues, like boiling away your gearoil.

Lets see what happens in First gear. 5400 in 2.45 first will get you to 37mph and on the shift, the Rs drop to 3200. You got torque down there? Well maybe you do, but will it be enough? But worse is, what happens if yur at 35mph, in Second gear just tooling along , minding your own business...... and you suddenly get the urge to hit the gas.
Consider what's about to happen .
You were at 2780. If the trans does NOT kickdown, that will increase to ~3000. Got torque?
But if she backshifts to first, the Rs will scream to 5070, and then she'll upshift in about a second and drop to 2990, got torque?
And listen, this is with 4.56s and 28"tires.
Thus you see that this combo will never be very satisfying, except it cruses at 65=2450, in .69od.
Or will it.

In the above scenario, the convertor stall is let's say stock.
But lets say your engine torque-peaks at 3500, so you get a 3500 stall. Now, your minimum rpm at WOT is gunna be close to that, so then, that's as good as it gets.
But now those 4.56s are all wrong for first gear, but if you change them, Second gear will get choked.
The point is, of course, to gear the car to torque peak at or near the speed you travel at, for most of the time, and let the other gears be what they will be.

Not so
with a nice tight 5-speed manual, or as in my case, using the GearVender as a gear splitter, behind the Commando 4-speed..It has a ratio of .78, which is about a close as you'll ever find.
With the right trans, in front of it, you can keep your engine on the pipe all thru the Eighth mile. which means that you can run a smaller engine or a smaller cam, and still have gobs of fun.

Choosing a manual or a stick, for the street, is kindof a personal thing.
Some guys are born to clutch, and some to not, and some just like what they like.
If I had money, I'd have a 5speed auto with a clutch.
This is the down in the weeds information I remember reading before, and this is why it's a difficult decision to make, and I'm pretty sure you posted it. I can't remember the thread it was in.
But yes, the main point you're making is that the gears need to match the horsepower/torque RPM range of the engine.
 
yup.. and just so ya know.. Early 727s didn't use a normal driveshaft.. they had a flange it bolted to(bottom pic) and a provision for the park cable.. (2 cables, 1 to shift, 1 to park) you can see it here..
Only the 1965 had a slip yoke and cable provision... i'm trying to find a spare right now.. they are very hard to find.. i drove 12 hours to get the one in my car...
View attachment 1716457014
View attachment 1716457013
Thanks for showing and explaining the difference of the push button transmission.
 
After driving my son's Dart last weekend (440/18-spline/3.23 with hydraulic throwout bearing) I don't think I'm gonna build another manual for myself. My left hamstring (injured in 2016) was barking at me all night. With that said, I have started going to the gym to swim and ride the stationary bike so it might get better over time. Manual is also much more expensive...
 
I like shiftin gears so that's how I roll. IMO, you have a little more control over what the car does.
 
After driving my son's Dart last weekend (440/18-spline/3.23 with hydraulic throwout bearing) I don't think I'm gonna build another manual for myself. My left hamstring (injured in 2016) was barking at me all night. With that said, I have started going to the gym to swim and ride the stationary bike so it might get better over time. Manual is also much more expensive...
To be honest, that's my hold up on putting a manual in my car. I didn't take care of myself when I was in my 20's and worked physically demanding jobs, like lawncare and landscape, and stone masonry. Then, almost twenty years in the National Guard in a maintenance section ended with two left hip surgeries and left ankle surgery. Short story long, i don't think a pressing a clutch is going to do my left leg any favors.
 
I have never, I’ll repeat that, NEVER ever regretted putting an overdrive in anything. It’s always worth it and is the one single modification that you can do to a vehicle that makes it more enjoyable to drive AND doesn’t change how the car performs. Everything I build now gets roller cams and overdrive. Cutting the TB crossmember and tunnel work sucks but it’s worth it and at least it can be ugly because it’s covered by carpet. US car tool and others now make bolt in crossmembers for most swaps so that’s an easy button. My D100 with a 3:55 gear and a 46RE rips down the freeway at 75-80 mph at ~2200 in OD. You can drive it for hours and not hate it or get run over by semis going 65mph. Do it, you won’t regret it when you’re finished.
 
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I have never, I’ll repeat that, NEVER ever regretted putting an overdrive in anything. It’s always worth it and is the one single modification that you can do to a vehicle that makes it more enjoyable to drive AND doesn’t change how the car performs. Everything I build now gets roller cams and overdrive. Cutting the TB crossmember and tunnel work sucks but it’s worth it and at least it can be ugly because it’s covered by carpet. US car tool and others now make bolt in crossmembers for most swaps so that’s an easy button. My D100 with a 3:55 gear and a 46RE rips down the freeway at 75-80 mph at ~2200 in OD. You can drive it for hours and not hate it or get run over by semis going 65mph. Do it, you won’t regret it when your finished.

Man i want that... i am at 2800rpm at 55mph... it gets old quick
 
I have never, I’ll repeat that, NEVER ever regretted putting an overdrive in anything. It’s always worth it and is the one single modification that you can do to a vehicle that makes it more enjoyable to drive AND doesn’t change how the car performs. Everything I build now gets roller cams and overdrive. Cutting the TB crossmember and tunnel work sucks but it’s worth it and at least it can be ugly because it’s covered by carpet. US car tool and others now make bolt in crossmembers for most swaps so that’s an easy button. My D100 with a 3:55 gear and a 46RE rips down the freeway at 75-80 mph at ~2200 in OD. You can drive it for hours and not hate it or get run over by semis going 65mph. Do it, you won’t regret it when your finished.
That's what I'm after, overdrive for highway use. I don't drive the car as much as I want for that reason.
 
the other option of course is the last of the mustang T5s

v6 mustang had a T5 in 2000-2004 that has similar ratios to the toyota r154 and W58
it comes with the longer input shaft
can get clutch plates in 9.5 10 and 10.5 inch
good metallergy in the gears, and with a steel counter gear retaining plate from 5 speeds.com is good for 300+ ftlb and a 350-400 bhp motor if not drag raced into bits.

can get input bearing retainers in 4.85 size (jeep) and a smaller chevy size... chose based on diameter of IBR spigot hole in bell, tube length and tube diameter... they all fit

The problem is it is electronic speedo
the stick will come up directly into the cross member
the shift rail is too high to be kinked down like the australians did

tail housings swaps needed
the rear shift versions become an issue because of that shift rail housing wanting share space with the cross member hump
the speedo drive still aligns with the cross member

leaving the chevy S10 housing with the front stick
it is none world class and won't fit without some simple machining
finding one for mechanical speedo is a pain
you need to sleeve the output shaft and use a split collar to mount a speedo gear in the right place...

basically if you get the front shift tail and use a 1/4 inch adapter to fit a MOPAR bellhousing to box, the back of the shifter area on the tail aligns with the very front of the braised to the tunnel, edge of the cross member hump. stick is forward but nothing a little bend in it can't fix.
provided you cut off the un needed Fin on rear of the box the shifter base bolts to.

not an easy swap which is why every year i advance so far then fail to get it done before show and race season and put the 4 speed back....

i'm a lazy procrastinator.... just aint got the get up and go... anymore :)

Dave
 
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Thanks for suggesting this approach. Sounds like you've put a lot of time into researching how to make it work. And I'm not planning on making a ton of power. My 318 is probably not making more than the numbers you posted as the limits of the T5 transmission.
 
the other option of course is the last of the mustang T5s

v6 mustang had a T5 in 2000-2004 that has similar ratios to the toyota r154 and W58
it comes with the longer input shaft
can get clutch plates in 9.5 10 and 10.5 inch
good metallergy in the gears, and with a steel counter gear retaining plate from 5 speeds.com is good for 300+ ftlb and a 350-400 bhp motor if not drag raced into bits.

can get input bearing retainers in 4.85 size (jeep) and a smaller chevy size... chose based on diameter of IBR spigot hole in bell, tube length and tube diameter... they all fit

The problem is it is electronic speedo
the stick will come up directly into the cross member
the shift rail is too high to be kinked down like the australians did

tail housings swaps needed
the rear shift versions become an issue because of that shift rail housing wanting share space with the cross member hump
the speedo drive still aligns with the cross member

leaving the chevy S10 housing with the front stick
it is none world class and won't fit without some simple machining
finding one for mechanical speedo is a pain
you need to sleeve the output shaft and use a split collar to mount a speedo gear in the right place...

basically if you get the front shift tail and use a 1/4 inch adapter to fit a MOPAR bellhousing to box, the back of the shifter area on the tail aligns with the very front of the braised to the tunnel, edge of the cross member hump. stick is forward but nothing a little bend in it can't fix.
provided you cut off the un needed Fin on rear of the box the shifter base bolts to.

not an easy swap which is why every year i advance so far then fail to get it done before show and race season and put the 4 speed back....

i'm a lazy procrastinator.... just aint got the get up and go... anymore :)

Dave
Thanks for this suggestion. I don't mind gathering parts to come up with a working solution.
 
Another option I've been looking at are "kits" available from Silver Sport Transmissions and Modern Drive Line. They're not cheap. All together with shipping I would be looking at $6,500-7,000, but it would everything needed to convert the car to use a Tremec TKX. Just want to hear some thoughts or experiences of this option.
 

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