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Bible 8hp70 transmission swap the world

Yellow_99TJ said:
how is the ability to shift to reverse from a higher gear in these? I see sequential shifters are the common aftermarket option, but for our use case I can see myself needing to go from 2nd or 3rd to R very quickly and downshifting 3 times would take too long. Any options for shifters that allow for that like the winters for the TH400 and 4l80s? Or wire a button that when you hit it and downshift it tells to trans to go into Reverse from whaterver gear its in?


Also how picky are these trannies when in manual mode? Will they let you hold a gear regardless of hitting redline in 2nd offroad or will they try to shift?
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Can't really answer the reverse part. Manual mode would be up to how your controller is handling that. If you have an aftermarket controller like a MaxxECU or Turbolamik, you should be able to tell the transmission to start and stay in whatever gear you choose. My 4runner if shifted into 1st will not shift out unless I move it to 2nd or D, the crap part is it will always start in 1st, this is factory stuff. With that said the aftermarket controllers should allow what you ask no problem. I might be in the Maxxecu camp here soon since I'm looking to ditch my 5vz.
 
Toy4rnr said:
Can't really answer the reverse part. Manual mode would be up to how your controller is handling that. If you have an aftermarket controller like a MaxxECU or Turbolamik, you should be able to tell the transmission to start and stay in whatever gear you choose. My 4runner if shifted into 1st will not shift out unless I move it to 2nd or D, the crap part is it will always start in 1st, this is factory stuff. With that said the aftermarket controllers should allow what you ask no problem. I might be in the Maxxecu camp here soon since I'm looking to ditch my 5vz.
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sweet. thank you. If the aftermarket controllers allow for staring in higher gears ( a must for east coast wheeling where I am) and quick shifing into R im sold on this swap. Do you know if the Maxx allows full control the same way the Turbolamik does? I know the Maxx uses the stock computer in the trans so im curiosu if the reflash gets rid of any of the limits on staring in 2 or 3 and shifting stright to R
 
Yellow_99TJ said:
sweet. thank you. If the aftermarket controllers allow for staring in higher gears ( a must for east coast wheeling where I am) and quick shifing into R im sold on this swap. Do you know if the Maxx allows full control the same way the Turbolamik does? I know the Maxx uses the stock computer in the trans so im curiosu if the reflash gets rid of any of the limits on staring in 2 or 3 and shifting stright to R
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Pancake and others are more well versed on the Maxx side of things, I'm starting to read up on it more since I want to use it for an all in one for a 1uzfe/8hp70 swap.

Directly from MaxxECU

Manual mode upshift offset

In manual mode, to prevent going into the revlimiter, MaxxECU can send a upshift signal before the actual rev-limiter. Example if your limiter is 7800rpm, you would most likely somewhere around 7000rpm start to initiate an upshift command, enter 800rpm here.

Note: enter "0" here to disable the upshift feature in manual mode, it will never upshift even driving in the revlimiter.
 
Yellow_99TJ said:
sweet. thank you. If the aftermarket controllers allow for staring in higher gears ( a must for east coast wheeling where I am) and quick shifing into R im sold on this swap. Do you know if the Maxx allows full control the same way the Turbolamik does? I know the Maxx uses the stock computer in the trans so im curiosu if the reflash gets rid of any of the limits on staring in 2 or 3 and shifting stright to R
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Maxx can be set up to NOT shift unless you tell it to. I’m not sure on a “reverse button” but I’ve had the same idea of doing that. I’m just not to the point of trying it yet.

I know that the jeeps default to a 2nd gear start from the factory. I’m pretty sure the maxx will activate “launch mode” in 2nd so I’m thinking it’ll start in whatever gear you tell it if you’ve got it set right.

My DomiWorks adapter is supposed to show up Friday 😎😎
 
Yellow_99TJ said:
how is the ability to shift to reverse from a higher gear in these? I see sequential shifters are the common aftermarket option, but for our use case I can see myself needing to go from 2nd or 3rd to R very quickly and downshifting 3 times would take too long. Any options for shifters that allow for that like the winters for the TH400 and 4l80s? Or wire a button that when you hit it and downshift it tells to trans to go into Reverse from whaterver gear its in?


Also how picky are these trannies when in manual mode? Will they let you hold a gear regardless of hitting redline in 2nd offroad or will they try to shift?
Click to expand...

I think extreme offroaders might be carving some new territory there, seeing how quick we can flip directions back and forth. 75RamRunner probably has the most experience there so far, even though he no longer runs one of these transmissions. But I mean technically, choosing directions is just sending can signals, like for example you can run these transmissions from CAN keypads instead of an OEM shifter if you wanted. But what that might mean...you might be able to put a momentary button on your steering wheel to momentarily grab reverse while you have it held down. Or maybe it's not momentary, and you just have a button for reverse on your left thumb, and a button for forwards on your right thumb just to toggle back and forth rapidly as needed.

The MaxxECU should be able to hold a single gear endlessly even sitting on the rev limiter as far as I've learned. Turbolamik can obviously do the same due to how much pure control that one offers. I'm not as sure about being able to launch in any gear you want with the MaxxECU, but I bet that's a pretty easy yes for the Turbolamik. That kind of stuff is great to know though, and I'll be researching to find out if it is something the MaxxECU can do.

Grendel said:
Well, I asked the dismantler and they said 23 spline out.

We'll see when it gets here.
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Hmm ok this will be really good info. On one hand I was kinda hoping the 29 spline google talked about existed just for stronger options, but on the other hand things would be way simplified if all the 6 bolt 8hp75s had the same output shafts


I've been dragging my feet on committing to taking my jeep off the road, but I just need to get it over with. The 545RFE annoys me more every day, especially knowing the solution is ready and waiting :grinpimp:
 
I was reading in the MaxxECU 8hp70 control documents that it might require the vehicle to be under a certain speed threshold before it allows you to shift to reverse.
 
Toy4rnr said:
I was reading in the MaxxECU 8hp70 control documents that it might require the vehicle to be under a certain speed threshold before it allows you to shift to reverse.
Click to expand...

Good notes. The next question, is that a limitation they have programmed in that could be easily modified, or is that something in the core logic of the factory TCM that will stop MaxxECU from being able to accomplish? Fingers crossed it's just something they programmed (logical because who would be crazy enough to actually want reverse while the wheels are spinning forward at any speed besides us :lmao:). If it's a hardcoded limit though, I'd say that's a +1 for Turbolamik
 
AgitatedPancake said:
Good notes. The next question, is that a limitation they have programmed in that could be easily modified, or is that something in the core logic of the factory TCM that will stop MaxxECU from being able to accomplish? Fingers crossed it's just something they programmed (logical because who would be crazy enough to actually want reverse while the wheels are spinning forward at any speed besides us :lmao:). If it's a hardcoded limit though, I'd say that's a +1 for Turbolamik
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Yeah it's under the shifter emulation section.

"Transmission Reverse Switch needs brake switch + OSS = 0 to engage."

If you follow the "transmission reverse switch" link it takes you to the DCT page so I don't know how much this applies but this is what's stated in that section.

"Only sent when DCT GEAR is GEAR 1, NEUTRAL or PARK, and vehicle speed below 10km/h and the brake input is active."

Might be worth clarifying with them as I'm curious as well, I might reach out. Since my engine plans changed MaxxECU is top of my list now.
 
YotaAtieToo said:
The guy in the video that put one in a 1 ton tacoma talks about what controller allows you to slap reverse.
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Yeah the Turbolamik. He mentions driveshaft speed ("50rpm") for the MaxxECU, I was trying to get concrete numbers or if there was a field that was configurable in the UI.
 
AgitatedPancake said:
I think extreme offroaders might be carving some new territory there, seeing how quick we can flip directions back and forth. 75RamRunner probably has the most experience there so far, even though he no longer runs one of these transmissions. But I mean technically, choosing directions is just sending can signals, like for example you can run these transmissions from CAN keypads instead of an OEM shifter if you wanted. But what that might mean...you might be able to put a momentary button on your steering wheel to momentarily grab reverse while you have it held down. Or maybe it's not momentary, and you just have a button for reverse on your left thumb, and a button for forwards on your right thumb just to toggle back and forth rapidly as needed.

The MaxxECU should be able to hold a single gear endlessly even sitting on the rev limiter as far as I've learned. Turbolamik can obviously do the same due to how much pure control that one offers. I'm not as sure about being able to launch in any gear you want with the MaxxECU, but I bet that's a pretty easy yes for the Turbolamik. That kind of stuff is great to know though, and I'll be researching to find out if it is something the MaxxECU can do.



Hmm ok this will be really good info. On one hand I was kinda hoping the 29 spline google talked about existed just for stronger options, but on the other hand things would be way simplified if all the 6 bolt 8hp75s had the same output shafts


I've been dragging my feet on committing to taking my jeep off the road, but I just need to get it over with. The 545RFE annoys me more every day, especially knowing the solution is ready and waiting :grinpimp:
Click to expand...
On the idea of momentary reverse switch, i was thinking along the lines of the sequnetial drift style shifters adding a button or level like we have for reverse lock outs now that when presses and the shifter is pressed to "downshift" would skip all other gears and catch reverse. So the logic for the computer would be- "if- button/lever is pressed and- downshift then- shift straight to reverse"



also curious on the Maxx vs Lamik control limits. I did some research on it and the Maxx using a reflashed VB as opposed to the lamik PCB sounds like it may cause some issues for our wild use case. I read somewhere that one of the TCUs would not allow to to skip gears, like go from 1st to 3rd without going to 2nd and vise versea causing issues when slowing down if you forget to shift, but im not sure if that was the Maxx or not. Full control with the Lamik is great, but the extra 1000$ hurts the wallet. would be curious if someone here has experince with the Maxx and other reflashed options to say for sure if it can do some of the offroad specific needs we have.

The math works far better for one of these over a 4l80 or the like with a 1500$ TCU not a 2600$ TCU.
 
Yellow_99TJ said:
On the idea of momentary reverse switch, i was thinking along the lines of the sequnetial drift style shifters adding a button or level like we have for reverse lock outs now that when presses and the shifter is pressed to "downshift" would skip all other gears and catch reverse. So the logic for the computer would be- "if- button/lever is pressed and- downshift then- shift straight to reverse"



also curious on the Maxx vs Lamik control limits. I did some research on it and the Maxx using a reflashed VB as opposed to the lamik PCB sounds like it may cause some issues for our wild use case. I read somewhere that one of the TCUs would not allow to to skip gears, like go from 1st to 3rd without going to 2nd and vise versea causing issues when slowing down if you forget to shift, but im not sure if that was the Maxx or not. Full control with the Lamik is great, but the extra 1000$ hurts the wallet. would be curious if someone here has experince with the Maxx and other reflashed options to say for sure if it can do some of the offroad specific needs we have.

The math works far better for one of these over a 4l80 or the like with a 1500$ TCU not a 2600$ TCU.
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Having a momentary on the shifter so while it's pressed, if you downshift it goes straight to reverse is an awesome idea, way better than a simple button on the wheel. And less chance of ****ing it up grabbing it accidentally too lol.

And yeah the price point is definitely a fair factor. Heck the MaxxECU Mini was only ~$800 with the starter harness, so super reasonable in comparison. Then if RusEFI does end up developing a controller, I would expect their option to end up under $500

Grendel said:
Whelp, fixed my output issues - bought a NP241 and a NWF box from The Freeak
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Did it end up being 23 spline or 29 spline? If 29, does the output shaft end basically flush with the transfer case mating surface (proud by like 1/8") like the 23 spline does?
 
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AgitatedPancake said:
I think extreme offroaders might be carving some new territory there, seeing how quick we can flip directions back and forth. 75RamRunner probably has the most experience there so far, even though he no longer runs one of these transmissions. But I mean technically, choosing directions is just sending can signals, like for example you can run these transmissions from CAN keypads instead of an OEM shifter if you wanted. But what that might mean...you might be able to put a momentary button on your steering wheel to momentarily grab reverse while you have it held down. Or maybe it's not momentary, and you just have a button for reverse on your left thumb, and a button for forwards on your right thumb just to toggle back and forth rapidly as needed.
Click to expand...

Providing info for those who wanted to know:

1. Shifting is super fast, no delay, the signal is much faster than the shift linkage for a winters can grab the gear so no problems there

2. My TCM was able to be programmed to hold a gear no matter what, it was less the controller used and more the HP Tuners interaction with the software in the valve body. My experience was the TCM was there to give the needed input/outputs and the valvebody computer actually was what controlled shift points/flow/etc

3. The shifter dial was worthless to me, i swapped in a T handle from a charger/challenger. Has manual mode to go +/- and was quick to go between gears HOWEVER we were not able to get around the brake input to shift into a different mode, meaning it had to see a blip of the brake to get into reverse. 1-8 and N required no input, but if you wanted to go to reverse or park you need to brake. I just piggy backed my brake light switch and it was plenty quick enough for most all scenarios however that was the biggest noted disadvantage from a gated shifter
 
75RamRunner said:
Providing info for those who wanted to know:

1. Shifting is super fast, no delay, the signal is much faster than the shift linkage for a winters can grab the gear so no problems there

2. My TCM was able to be programmed to hold a gear no matter what, it was less the controller used and more the HP Tuners interaction with the software in the valve body. My experience was the TCM was there to give the needed input/outputs and the valvebody computer actually was what controlled shift points/flow/etc

3. The shifter dial was worthless to me, i swapped in a T handle from a charger/challenger. Has manual mode to go +/- and was quick to go between gears HOWEVER we were not able to get around the brake input to shift into a different mode, meaning it had to see a blip of the brake to get into reverse. 1-8 and N required no input, but if you wanted to go to reverse or park you need to brake. I just piggy backed my brake light switch and it was plenty quick enough for most all scenarios however that was the biggest noted disadvantage from a gated shifter
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Was that with the Turbolamik?
 
They confirmed it's 29 spline, so will do a 29 spline input into the 241 based underdrive I bought.

Now is there anyway to use OEM controllers in a stand alone config? I don't need all the crap in a 1979 Jeep J10.
 
75RamRunner said:
Providing info for those who wanted to know:

1. Shifting is super fast, no delay, the signal is much faster than the shift linkage for a winters can grab the gear so no problems there

2. My TCM was able to be programmed to hold a gear no matter what, it was less the controller used and more the HP Tuners interaction with the software in the valve body. My experience was the TCM was there to give the needed input/outputs and the valvebody computer actually was what controlled shift points/flow/etc

3. The shifter dial was worthless to me, i swapped in a T handle from a charger/challenger. Has manual mode to go +/- and was quick to go between gears HOWEVER we were not able to get around the brake input to shift into a different mode, meaning it had to see a blip of the brake to get into reverse. 1-8 and N required no input, but if you wanted to go to reverse or park you need to brake. I just piggy backed my brake light switch and it was plenty quick enough for most all scenarios however that was the biggest noted disadvantage from a gated shifter
Click to expand...

Thanks for sharing more details of your experiences with us, definitely helpful! Also I didn't know you were tuning the factory TCM with HPTuners, that's pretty interesting.

Grendel said:
They confirmed it's 29 spline, so will do a 29 spline input into the 241 based underdrive I bought.

Now is there anyway to use OEM controllers in a stand alone config? I don't need all the crap in a 1979 Jeep J10.
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Cool, nice to confirm that there is a middle ground output shaft size between 23 and 43 spline. I haven't done a ton of research on it, but it seems like 2024+ is "GPEC5" computers which are pretty locked down. From quick searching I didn't see any standalone harnesses or anything for them. Some AI recommendations say you might need to run an older GPEC2 computer + standalone harness, and then use something like the Sound German controller to make it play nice? But the 8hp75 might be a different generation betwen the two (gen 2 vs gen 3)? Hmm.

But this is all just a coarse understanding from a very little bit of research, pretty far outside of my wheelhouse
 
75RamRunner said:
3. The shifter dial was worthless to me, i swapped in a T handle from a charger/challenger. Has manual mode to go +/- and was quick to go between gears HOWEVER we were not able to get around the brake input to shift into a different mode, meaning it had to see a blip of the brake to get into reverse. 1-8 and N required no input, but if you wanted to go to reverse or park you need to brake. I just piggy backed my brake light switch and it was plenty quick enough for most all scenarios however that was the biggest noted disadvantage from a gated shifter
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For a button, if using a PDM or other smart controller, it seems like you could have it drive the brake input and flip to reverse when the oh **** reverse button is pushed.
 
So it looks like I am going with Hotwire.com for this, which includes a stand alone trans controller, as the other missing modules all do stuff for the trans. Makes sense, but meh...
 
Grendel said:
So it looks like I am going with Hotwire.com for this, which includes a stand alone trans controller, as the other missing modules all do stuff for the trans. Makes sense, but meh...
Click to expand...

I'll be curious which standalone controller they set you up with, most don't seem to claim they support those new 8hp75s yet. Unless those can have the TCM in the valve body deleted with the breadboard soldered in as a replacement, and run on a TurboLamik like the 8hp70
 
Final pieces of the puzzle, transmission mount and driveline tubing. I'm thinking I'll dive into the swap next weekend. This plate fits the Dodge Truck transmissions

8HP70 - Transmission Mount - 1.JPG


Note that if you have a flat plate mount like this, the rear 2 bolt holes need a 3/16" spacer (see the air gap between plate and transmission)

8HP70 - Transmission Mount - 2.JPG


Here are the dimensions for it, the lower left hole is the zero point for these measurements. The transmission uses M10 x 1.5 bolts I'm pretty sure, so 0.395" diameter. I went big with 0.44" holes because sloppy plasma table, but I don't think the oversize would be an issue even with accurate laser holes.

8HP70 - Transmission Mount - 3.JPG


IMG_2826.jpeg



And driveshaft stuff

IMG_2828.jpeg
 
06h3 said:
what CV is that
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Dodge 1350. I'm in a bit of a pickle, because I have two Dodge 1350 shafts with the large 3.125" pilot diameter, and my tcase flanges have the 2" pilot. I've got the head of another Ford 1350 CV that has the correct 2" pilot so I could swap it out when I put that new centering ball in, but I'd rather use the two matching CVs as front and rear shafts for future convenience. So I'm thinking I might just make some little 2"-3.125" pilot adapter plates and bolt/tack them to the tcase flanges
 
AgitatedPancake said:
Dodge 1350. I'm in a bit of a pickle, because I have two Dodge 1350 shafts with the large 3.125" pilot diameter, and my tcase flanges have the 2" pilot. I've got the head of another Ford 1350 CV that has the correct 2" pilot so I could swap it out when I put that new centering ball in, but I'd rather use the two matching CVs as front and rear shafts for future convenience. So I'm thinking I might just make some little 2"-3.125" pilot adapter plates and bolt/tack them to the tcase flanges
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future you will find a reason to hate current you's idea of convenience :flipoff2: there is no wrong answer
 
AgitatedPancake said:
Final pieces of the puzzle, transmission mount and driveline tubing. I'm thinking I'll dive into the swap next weekend. This plate fits the Dodge Truck transmissions

8HP70 - Transmission Mount - 1.JPG


Note that if you have a flat plate mount like this, the rear 2 bolt holes need a 3/16" spacer (see the air gap between plate and transmission)

8HP70 - Transmission Mount - 2.JPG


Here are the dimensions for it, the lower left hole is the zero point for these measurements. The transmission uses M10 x 1.5 bolts I'm pretty sure, so 0.395" diameter. I went big with 0.44" holes because sloppy plasma table, but I don't think the oversize would be an issue even with accurate laser holes.

8HP70 - Transmission Mount - 3.JPG
Click to expand...
I had been thinking about this for some time, now I don't have to think about it anymore, good stuff!
 
I would for sure get a 3.125 adapter. I have one and I like the idea that if I am ever in a bind, I can go to different parts finding stuff on the road or on a dry lakebed.

I never tacked mine, it seems to just sit snug and happy. you have to pry it off usually so it is a snug fit.
 
Rnuovrcj5 said:
Since I’m doing an engine swap at the same time, I’m trying to resist the temptation to to swap the MaxxEcu mini for a Race with the LS harness and have it all integrated instead of multiple computers to run every thing.
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That's the way

Edit: You also get DBW, Cruise control, extra inputs for various sensors (like fuel pressure, various temps, ...) and extra outputs (fans, multiple fuel pump etc)
 
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