Slant 6 with an AX15?

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Chrono

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Hey guys, been awhile. I've still got the Duster, and I'm looking at (finally) starting the restomod process by the end of the year.

I'm still hung up on transmission options. I'm interested in getting an AX15 behind the Slant. Has anyone done this? Who makes an adapter for this if they have?

Any help is always appreciated!
 
Can’t remember anyone completing an AX15 swap, only T5’s.

But I started adapting an R154 to a slant and they have the same mounting face. Still have the adapter and bellhousing, but the project ended up being too rusty and went away.

If you wanted, I could try and dig up some pictures later.

And I have no plans for the parts I still have...
 
Can’t remember anyone completing an AX15 swap, only T5’s.

But I started adapting an R154 to a slant and they have the same mounting face. Still have the adapter and bellhousing, but the project ended up being too rusty and went away.

If you wanted, I could try and dig up some pictures later.

And I have no plans for the parts I still have...
I'd love to see some pictures
 
I think I had Novak do the adapter plate, but not certain. It could have been the other place that does adapters like this (of which I can't remember their name right now). I had them leave it as a blank rather than shape the outside, I think because I didn't know where the bellhousing bolts would land. I had them put holes in to match a Mopar bearing retainer so I could center the bellhousing up on it. Ended up being a Hemi bearing adapter as it was the only one big enough to fit over the input shaft.

Here is the adapter as I got it:

Adapter 002.jpg
Adapter 004.jpg
Adapter 006.jpg
Adapter 007.jpg
Adapter 008.jpg


Note that to make this work, I had to saw the tube off the R154 bearing retainer. Needed to keep the Toyota bearing retainer but the the Mopar bearing retainer wouldn't fit over the throw out bearing slide.

I even went and bought a Stage 3 clutch from Spec to fit the slant 6 flywheel and match the input splines on the R154.

Here is a picture of the input shaft and how far the pilot bushing adapter would have to reach:

Valiant 011.jpg


Note that the AX15 input shaft might be a different length. This is just for reference.
 
Here are pictures of the transmission and bellhousing:

Adapter 011.jpg
Adapter 012.jpg
Adapter 013.jpg
Adapter 014.jpg
Adapter 017.jpg
Adapter 018.jpg


As I recall, the adapter plate could have used some more shaping, but I got tired of messing with it and figured I would clean it up some more before finished the project. Looks better than I remember it, though.
 
Another option you might look into is grabbing a bellhousing and AX15 out of a Dakota and tracking down one of the 727 adapter plates for a slant 6. I think they used them in trucks.

With that you should be able to bolt up the transmission to a slant 6, but not sure what other problems you would have.

Biggest issue there is how super rare the adapter plates were.
 
Alright. You've given me quite a bit to think about.
Aren't the R154 and AX15 the same transmission?
AX15s are plentiful at my local U-Pull it
Is that the 3 or 4 speed bell housing you used in those pictures?
 
Alright. You've given me quite a bit to think about.
Aren't the R154 and AX15 the same transmission?
AX15s are plentiful at my local U-Pull it
Is that the 3 or 4 speed bell housing you used in those pictures?

R154 and AX15 are from the same family of transmissions and they both have the same bolt pattern for the bellhousing. Big difference between the two is gear ratios, the R154 is geared for a sports car (MK3 Supra Turbo) while the AX15 is for a truck. Pretty sure the input shaft is different between the two, and not sure about the shifter location.

I know that someone on here has done an AX15 swap with a V8, might give you some useful info.

I used a 4 speed bellhousing.
 
R154 and AX15 are from the same family of transmissions and they both have the same bolt pattern for the bellhousing. Big difference between the two is gear ratios, the R154 is geared for a sports car (MK3 Supra Turbo) while the AX15 is for a truck. Pretty sure the input shaft is different between the two, and not sure about the shifter location.

I know that someone on here has done an AX15 swap with a V8, might give you some useful info.

I used a 4 speed bellhousing.

Considering the Slant 6 is a truck motor, it should be fine! Lmao

But seriously, if I decide I don't like the gear ratio of the AX 15, I'll swap it to the R154

So, are you interested in parting ways with that adapter?
 
That AX-15 has very wide 1-2, and 2-3 splits, then a lil shorter fourth.
I think you can get an NV3500 from a Jeep, or a GM truck, with a removable bellhouse. It might be easier to find a bellhouse for that, IDK. but the chevy inputs are a lot shorter. IDK if you can swap the Mopar guts into the Chevy case.
The NV has very similar ratios to the AX-15, but the progression is a lil smoother. You will likely want to run 3.91s or so with the NV, compared to 3.55s with the -15.
Here are the ratios I have recorded,there are others;

AX-15
3.83-2.33-1.44-1.00-.79od ......with 3.55s you get
13.60-8.27-5.11-3.55-2.80, splits of
.61-.62-.69-.79

NV3500Dakota
3.49-2.14-1.38-100-.73od ......with 3.91s you get
13.65-8.37-5.40-3.91-2.85, splits of
.61-.645-.725-.73 .....Here you can see the nicer progression, and shorter 4th
 
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Considering the Slant 6 is a truck motor, it should be fine! Lmao

But seriously, if I decide I don't like the gear ratio of the AX 15, I'll swap it to the R154

So, are you interested in parting ways with that adapter?

Wouldn’t be opposite to parting ways. Have absolutely no plans for it. Need to dig it out though, not sure where it is.

You could look at the AR5 or MA5 for a cheaper alternative to the R154, too.
 
That AX-15 has very wide 1-2, and 2-3 splits, then a lil shorter fourth.
I think you can get an NV3500 from a Jeep, or a GM truck, with a removable bellhouse. It might be easier to find a bellhouse for that, IDK. but the chevy inputs are a lot shorter. IDK if you can swap the Mopar guts into the Chevy case.
The NV has very similar ratios to the AX-15, but the progression is a lil smoother. You will likely want to run 3.91s or so with the NV, compared to 3.55s with the -15.
Here are the ratios I have recorded,there are others;

AX-15
3.83-2.33-1.44-1.00-.79od ......with 3.55s you get
13.60-8.27-5.11-3.55-2.80, splits of
.61-.62-.69-.79

NV3500Dakota
3.49-2.14-1.38-100-.73od ......with 3.91s you get
13.65-8.37-5.40-3.91-2.85, splits of
.61-.645-.725-.73 .....Here you can see the nicer progression, and shorter 4th

NV3500 doesn’t have a removable bellhousing. At least not one I am aware of.
 
That AX-15 has very wide 1-2, and 2-3 splits, then a lil shorter fourth.
I think you can get an NV3500 from a Jeep, or a GM truck, with a removable bellhouse. It might be easier to find a bellhouse for that, IDK. but the chevy inputs are a lot shorter. IDK if you can swap the Mopar guts into the Chevy case.
The NV has very similar ratios to the AX-15, but the progression is a lil smoother. You will likely want to run 3.91s or so with the NV, compared to 3.55s with the -15.
Here are the ratios I have recorded,there are others;

AX-15
3.83-2.33-1.44-1.00-.79od ......with 3.55s you get
13.60-8.27-5.11-3.55-2.80, splits of
.61-.62-.69-.79

NV3500Dakota
3.49-2.14-1.38-100-.73od ......with 3.91s you get
13.65-8.37-5.40-3.91-2.85, splits of
.61-.645-.725-.73 .....Here you can see the nicer progression, and shorter 4th


I have plans to swap a 8.25 out of a Dakota/Durango with a factory LSD. It'll ditch the glassy 7.25 that's in the Duster.
And 3.55 was the rear gear I wanted too.
The 7.25 has a 2.74 in it
 
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