Could I put an AX-15 behind my F with these AA TR-4050 and AX-15 to TLC T-case Adapters? (1 Viewer)

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

Joined
Jun 7, 2016
Threads
22
Messages
861
Location
Connecticut
I've been thinking about this since Axis came out with their split case option and just came across these on the AA site. This would allow me to use my existing T case and seems much more affordable than the Axis split case adapter or an H55/split case swap.

TR4050 & AX15 TO TLC 10 SPL

TR4050 & AX15 TO TLC 16 SPL

TR4050 & AX15 TO TLC 19 SPL

0002800_tr4050-ax15-to-tlc-10-spl.jpeg


I believe TLC was using the AX-15 or NV3500/NV3550 behind LS engines, connected to an Atlas TC, in their stick shift Icon builds based on some videos I've seen. I would just be looking for something nicer to drive behind my F engine. More gears, syncros, and an OD (not that the F likes to make revs, but that's why I want to keep them down if cruising on the highway.)

Given the F bell housing can be used to adapt to to a GM trans like the SM420, something like this should get me pretty close on the nose side. Its been done with an NV4500 just to see if its possible.

GMAX_front_34_assembly1.jpg

yes I think that should work. You’ll need the 10.5” chevy clutch disc and figure something out for a pilot bearing.
i did this with an NV4500 in 2016.


The TR-4050 looks like a really interesting option for someone who building something more hardcore, and Fourwheeler had some great things to say about it

Am I missing something here?
 
Nope, you aren't missing anything
other then potential shifter location issues. It would be wasteful to do this and not use a splitcase though unless you are already invested in a ORION IMO
 
Nope, you aren't missing anything
other then potential shifter location issues. It would be wasteful to do this and not use a splitcase though unless you are already invested in a ORION IMO
Why is that? Ive never had one

I see what you're saying about shifter locations. Up until now this has been purely hypothetical... Ill have to take off my cover and pull a tape.
 
Last edited:
Did some measuring over the weekend. The AX15 shifter is towards the rear of the trans. 16.5" case length plus the adapters means it would definitely put the shifter hole far back, towards the back of the 3 speed trans cover, and make for a long drivetrain. It could work with a dog leg in the shifter since it would want to come up through the front of my Tuffy console. Other truck trans swaps seem to have the shifter more forward on the box, but I suspect that since that was used in cars as well that is why it is so far back. People do manage to run toyboxes and ranger ODs so Im sure it could be done.

Maybe this is a better option for a small V8 or R2.8 swap that would shift it forward, or an Atlas engine. :meh:
 
agreed. Would be nice with something like new aluminum DI 4.3 V6 or a Honda engine. Something super light weight and efficient.
 
agreed. Would be nice with something like new aluminum DI 4.3 V6 or a Honda engine. Something super light weight and efficient.

That could be sweet.
 
agreed. Would be nice with something like new aluminum DI 4.3 V6 or a Honda engine. Something super light weight and efficient.
The LV3 DI V6 is on my short list of engines to put into my trail truck to replace the old SBC. Those things will do 300/300 easy.
 
Did some measuring over the weekend. The AX15 shifter is towards the rear of the trans. 16.5" case length plus the adapters means it would definitely put the shifter hole far back, towards the back of the 3 speed trans cover, and make for a long drivetrain. It could work with a dog leg in the shifter since it would want to come up through the front of my Tuffy console. Other truck trans swaps seem to have the shifter more forward on the box, but I suspect that since that was used in cars as well that is why it is so far back. People do manage to run toyboxes and ranger ODs so Im sure it could be done.

Maybe this is a better option for a small V8 or R2.8 swap that would shift it forward, or an Atlas engine. :meh:
It would be a sweet drivetrain, but unless you fall into the parts for nearly free, you're going to be spending a serious chunk of change. Have you driven an H42 equipped FJ40? Do you think your F-engine has the power to push you truck in 5th gear? I know the F engine in my '69 with 4.10 gears and 33" tires doesn't have the ass to use an OD unless I am headed down a hill.
 
I've been thinking about this since Axis came out with their split case option and just came across these on the AA site. This would allow me to use my existing T case and seems much more affordable than the Axis split case adapter or an H55/split case swap.

TR4050 & AX15 TO TLC 10 SPL

TR4050 & AX15 TO TLC 16 SPL

TR4050 & AX15 TO TLC 19 SPL

View attachment 2991823

I believe TLC was using the AX-15 or NV3500/NV3550 behind LS engines, connected to an Atlas TC, in their stick shift Icon builds based on some videos I've seen. I would just be looking for something nicer to drive behind my F engine. More gears, syncros, and an OD (not that the F likes to make revs, but that's why I want to keep them down if cruising on the highway.)

Given the F bell housing can be used to adapt to to a GM trans like the SM420, something like this should get me pretty close on the nose side. Its been done with an NV4500 just to see if its possible.

View attachment 2991822


The TR-4050 looks like a really interesting option for someone who building something more hardcore, and Fourwheeler had some great things to say about it

Am I missing something here?


Looks like you have a 11/69, I have 10/69 both are 70 models. I would sell mine before changing out the transmission. Did a H42 into my 68 FJ40 back in 1994. Would never do it again in a E-9/72 FJ40. Torque tube is closer and different shape on FJ40 before the 9/72 73 started. Same with the floor at the back of the transmission hump. Keeping the F engine would go H55F with split case to a avoid adapters adding to the running gear length. Four speed bellhousing is the same length as the three and H55F bolts up to it. Transfer output flanges need to be dealt with. Length would obviously be longer than a three speed but not much as using different five speed with adapters.
 
Have you driven an H42 equipped FJ40? Do you think your F-engine has the power to push you truck in 5th gear?

Still have the original F145 and one barrel carburetor in my 68 FJ40. Hasd a H42 since 1994. With stock 4.11:1 diffs and 31X10.50X15". There are times it could use another gear.
 
It would be a sweet drivetrain, but unless you fall into the parts for nearly free, you're going to be spending a serious chunk of change. Have you driven an H42 equipped FJ40? Do you think your F-engine has the power to push you truck in 5th gear? I know the F engine in my '69 with 4.10 gears and 33" tires doesn't have the ass to use an OD unless I am headed down a hill.w
Thanks, it is more "could I" right now. Cost wise I dont think it would be too bad vs other options, especially seeing what people want for used 4 speeds that would need rebuilding. They still sell brand new AX-15s for $1690. H55F (~4000s) and a rebuilt split case is even more $$$.

Having the 3 speed right now, first isn't that low, 2.76 I think, and with it not having a syncro I've got to be going pretty slow to even use it. 3 on the column is really cool, but the novelty wears off and the mechanism keeps me from adding power steering. I've got a scout box and a Saginaw pump adapter just sitting on the shelf.

4 speed is the other option I was considering, and seems to be the path of least resistance. When I saw this adapter I started reading about how nice it shifts, and having the 5th gear not to push it, but to keep the revs down on the old F if I was cruising on the highway. I would not be trying to over take, and can always downshift. Conversely I dont have a tach but 1:1 with 4.10s at highway speeds sure isn't putting along. The tradeoff is obviously length.

I was hoping to keep the motor, eventually go 2F, but if I ever did some non Toyota engine swap this AX15 trans to a toyota case its probably the way I would go based on use and how I drive. I wouldnt go bigger than a 4.8L LS. The other engine I thought would be cool is the Vortec 3700 GM Atlas i5 with an AX15, not a ton of power (enough to move an H3,) but revs higher and sounds sooooo good.

Looks like you have a 11/69, I have 10/69 both are 70 models. I would sell mine before changing out the transmission. Did a H42 into my 68 FJ40 back in 1994. Would never do it again in a E-9/72 FJ40. Torque tube is closer and different shape on FJ40 before the 9/72 73 started. Same with the floor at the back of the transmission hump. Keeping the F engine would go H55F with split case to a avoid adapters adding to the running gear length. Four speed bellhousing is the same length as the three and H55F bolts up to it. Transfer output flanges need to be dealt with. Length would obviously be longer than a three speed but not much as using different five speed with adapters.
Thanks, I figured Id have to do some welding for any swap and add an AA rear t case cross member. The floor is so patched in my truck I dont mind modifying it. I'll probably go aqualu 3/4 someday and put on a 4 speed tunnel like Ive seen done on Mud. To your point, I agree with you and in hindsight I would have bought a later model rig, maybe one that was already modified so I wouldn't feel as guilty if I make changes. With the market being what it is, options are few and far between. I appreciate the input.
 
Skip that rear t case crossmember and do something like what is in a FJ60
 
Thanks, it is more "could I" right now. Cost wise I dont think it would be too bad vs other options, especially seeing what people want for used 4 speeds that would need rebuilding. They still sell brand new AX-15s for $1690. H55F (~4000s) and a rebuilt split case is even more $$$.

Having the 3 speed right now, first isn't that low, 2.76 I think, and with it not having a syncro I've got to be going pretty slow to even use it. 3 on the column is really cool, but the novelty wears off and the mechanism keeps me from adding power steering. I've got a scout box and a Saginaw pump adapter just sitting on the shelf.

4 speed is the other option I was considering, and seems to be the path of least resistance. When I saw this adapter I started reading about how nice it shifts, and having the 5th gear not to push it, but to keep the revs down on the old F if I was cruising on the highway. I would not be trying to over take, and can always downshift. Conversely I dont have a tach but 1:1 with 4.10s at highway speeds sure isn't putting along. The tradeoff is obviously length.

I was hoping to keep the motor, eventually go 2F, but if I ever did some non Toyota engine swap this AX15 trans to a toyota case its probably the way I would go based on use and how I drive. I wouldnt go bigger than a 4.8L LS. The other engine I thought would be cool is the Vortec 3700 GM Atlas i5 with an AX15, not a ton of power (enough to move an H3,) but revs higher and sounds sooooo good.


Thanks, I figured Id have to do some welding for any swap and add an AA rear t case cross member. The floor is so patched in my truck I dont mind modifying it. I'll probably go aqualu 3/4 someday and put on a 4 speed tunnel like Ive seen done on Mud. To your point, I agree with you and in hindsight I would have bought a later model rig, maybe one that was already modified so I wouldn't feel as guilty if I make changes. With the market being what it is, options are few and far between. I appreciate the input.


When I put a four speed in my 68 I did use the later seventies transmission cover trimmed at the back. Worked great.and used the four speed boots that just bolted to the hump.

A H55F does cost anywhere near $4,000 new. Need to shop around.
 
I believe TLC was using the AX-15 or NV3500/NV3550 behind LS engines, connected to an Atlas TC, in their stick shift Icon builds based on some videos I've seen.

They're using them on their Bronco-mishmash-whatever-those-are rigs also. The Bronco crowd in general likes to swap in AX15s but they prefer the NV3500/3550. Unfortunately there are almost no new parts for the 3550s. I think the fascination with the AX15 is that it's cheap and available new. They do have a fairly tall 5th gear if you've got the correct torque band which can be a good thing.

But the AX is no match for the NVG in driveability. Probably just as strong but there are no numbers for the AX. The shifting is no where near as refined as the 3550. Reverse is not synchro'd. Let me repeat that - Reverse is not synchro'd. You're not going to be rocking a vehicle with an AX back and forth to get unstuck near as easily as with a transmission with a synchro'd reverse gear. There's also the issue of the rear output seal on the AX which rides on the input to your t-case. It's not a sealed unit per se. I assume the adapters will address that. Plus there's a spacer needed or you'll have to trim the transmission output.

AX15s aren't bad or anything. They would probably be just fine in a 40. They're just not very refined in my view. I wouln't run one behind a V8 if I wanted longevity. Not many other choices for a new stick these days though. The TR-4050 is overkill for an F, F1.5, or 2F.
 
I have just placed my order for an H55F and split trasfercase. It will bolt up to my 2F bell housing and does not increase the overall length by much over the 4 speed and TC and in some countries the FJ4 had these gear boxes. The only adapter I need is for the Cummins R2.8 and keeps the bell housing in the same place it was behind the original 2F and the 155F.
 
I have just placed my order for an H55F and split trasfercase. It will bolt up to my 2F bell housing and does not increase the overall length by much over the 4 speed and TC and in some countries the FJ4 had these gear boxes. The only adapter I need is for the Cummins R2.8 and keeps the bell housing in the same place it was behind the original 2F and the 155F.
Very nice, how far forward is the R2.8 going to shift the front face of the trans from where the F/2F had it?

I was looking at the AX15 more because I saw the adapters and thought - theoretically - it could work. I think the shifter would be by my hip though.
 
I think that the adapter is 1.5 inches thick that bolts between the 2F bell housing and the R2.8 block. I will have to move the radiator back toward the engine which will make room for the other coolers.

 
Bringing this thread back from the dead.

Currently, I have a 76 2F that was rebuilt about 20 years ago, with an '3 speed' bellhousing going to an SM420 behind it and 4.88s in the diffs.
Crawl Ratio is 67:1

I am revamping the whole truck. It WILL get fuel injection (Sniper).
I'd really like to run a 5 speed OD transmission, but I also want to keep a similar crawl ratio as the SM420, and have 2x chunks with extra 4.88s in them as spares, so I'd prefer not to regear if i can help it.

Consideration is a new H55f with split case, but the only lower gearing options that don't under drive the high range (negating the 5th gear of the H55F) are 3:1 which will give me 70:1 so I'd have slightly lower crawl ratio.

TR4050 with the split case stock gear ratio of 2.3:1 would give me 69:1 and a deeper overdrive, though I wonder if the power of the 2F could turn that?
The 3.3:1 t-case gears with a 10% under drive will give about the same OD ratio as the stock H55F and a 99:1 crawl ratio (WOOHOO!)

This might be something to strongly consider vs a H55f/3:1 split case... (70:1 crawl ratio).
 
Bringing this thread back from the dead.

Currently, I have a 76 2F that was rebuilt about 20 years ago, with an '3 speed' bellhousing going to an SM420 behind it and 4.88s in the diffs.
Crawl Ratio is 67:1

I am revamping the whole truck. It WILL get fuel injection (Sniper).
I'd really like to run a 5 speed OD transmission, but I also want to keep a similar crawl ratio as the SM420, and have 2x chunks with extra 4.88s in them as spares, so I'd prefer not to regear if i can help it.

Consideration is a new H55f with split case, but the only lower gearing options that don't under drive the high range (negating the 5th gear of the H55F) are 3:1 which will give me 70:1 so I'd have slightly lower crawl ratio.

TR4050 with the split case stock gear ratio of 2.3:1 would give me 69:1 and a deeper overdrive, though I wonder if the power of the 2F could turn that?
The 3.3:1 t-case gears with a 10% under drive will give about the same OD ratio as the stock H55F and a 99:1 crawl ratio (WOOHOO!)

This might be something to strongly consider vs a H55f/3:1 split case... (70:1 crawl ratio).
That underdrive on the 4:1 splitcase may not bother you with the 2-5 gearing split on the H55f? Would certainly suck with the 420's 3 useful forward gears though.
 

Users who are viewing this thread

Back
Top Bottom