Ahhh, interesting. You are having the transfer case input shaft changed out. We did not go that direction on the 8HP75. We did a custom intermediate shaft that adapts the output shaft on the 8HP75 to the input shaft design on the A343F. The weak point is the A343F Output Shaft design. We had to change to a superalloy for the intermediate shaft design, as the FEA on the shaft showed some weak points and we wanted a 1.5 safety factor. This would be a stronger way to go, but does require the transfer case to be torn down and built back up. This was a fork in the development where we went the other direction. Thanks for sharing. I will post pictures of the 3D models once I get clearance from DomiWorks. I do not want to share his IP before he is ready.
1FZ trans swaps 6R80 10R80 and more (2 Viewers)
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- #42
I bought a newly rebuilt and. Updated trans. I could not get any help on the r&d which upset me but I needed to move on. I was not capable to do any of the r&d other than practacle input on what I needed and making sure it was done correctly. I supplied donor parts.
I had contacted Domni Works also but they showed no interest probably due to my transmission choice. In the beginning I was going to go with ZF but ended up opting for the Ford products. Had I done better research I may have done ZF
But here I am. We will both have tales to tell!
You willl likely finish before me due to what else I have going on
Cheers
I had contacted Domni Works also but they showed no interest probably due to my transmission choice. In the beginning I was going to go with ZF but ended up opting for the Ford products. Had I done better research I may have done ZF
But here I am. We will both have tales to tell!
You willl likely finish before me due to what else I have going on
Cheers
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- #43
I did try to design it with a coupling/intermediary shaft at first, but it would have made the overall package too long. It was either tear down trans and make a new output shaft, or tear down transfer and make new input shaft. Second option was cheaper and looks stronger
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- #44
Was also a mechanically simpler solution, less pieces and more like stock. Not sure which way was less expensive. My one off transfer input shaft was $850 USD. How much was your coupling shaft, and how did it affect length between face of trans to face of transfer?
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About the same for the intermediate shaft on cost, one off. It is similar in process steps. Has internal splines on one end, external on the other.
As far as overall length goes, the transmission mount comes into play. We made another design decision to stay with the stock trans mount. This has a given width to it and it has to fit in between the transfer case and the transmission. This dictates the majority of the length of the transfer case adapter. The intermediate shaft does dictate some additional length, but only on the order of 6mm or so. If we had gone with a new transfer case input shaft, we would have saved the 6mm in overall length, but thought it was not worth the install complexity for the average potential customer, long term.
Picture below of my version of the tail housing adapter 3D model. This is my IP. We designed in parallel and then compared designs, taking the best from both. This is not the final design. I will share that when I get permission from DomiWorks. You can see how using the stock transmission mount geometry dictates most of the length of the transfer case adapter. The increase in overall length of the assembly is driven by the Bell Housing adapter, resulting in a movement of Transfer Case rearward by 68.7 mm (2.7").
Also, we do have an intermediate shaft support bearing in the tail housing adapter, much like the stock A343F. That did not cost us any additional length. It is not a wet bearing like the stock A343F, but a sealed, pre lubed bearing. The end of the 8HP75 is sealed, unlike the A343F which pushes ATF into the tail housing and lubricates the wet bearing.
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- #46
Very nice! I am using the stock x member but didn't sort out the actual mount, my guy was not that interested and I have no design toll ability. I just left lots of aluminum to work with and will figure it out.
You have a very nice tidy design, hopefully you can make a saleable kit. Don't think mine will be, unless i can do a better job on the 10 speed next.
You have a very nice tidy design, hopefully you can make a saleable kit. Don't think mine will be, unless i can do a better job on the 10 speed next.
Just from your visual, I would strongly advise removing the sealed single row ball bearing from your design. That is going to bite you hard in the ass down the road. There are ways you could constrain that shaft with bearings, but that is not it and it's 100% unnecessary.
Countersunk head screws are never ideal.
Machine that from one piece or make a pattern and cores and have it cast. That part, as one solid piece, presents no challenge for any common full B axis HMC. Any extra material cost is 100% mitigated by eliminating four other setups to machine the two additional parts.
As I said above, not the final design. This was my preliminary design that we morphed as we did design reviews. The final design uses low profile cap head bolts. I will share that as soon as DomiWorks signs off on divulging the IP.
DomiWorks wanted a modular design so that he could swap end plates for various options. The 3 piece design supports that.
He has done several of these flavors of designs with intermediate shafts and used a support bearing for the intermediate shaft. I will defer to his design opinion on that, as this will be his product to sell and support, not mine.
Thanks,
Mike
Fair enough. With Domiworks 4 year stockpile of business experience I'm sure he's got it down.
When trying to identify Domiworks manufacturing capabilities I found this read interesting: Inspection and quality control - https://www.domi-works.com/pages/inspection-and-quality-control
I don't have the guts to claim 3D scanning as geometric part inspection, but it's a big enough deal for them make a whole page on their website and use buzzwords like "ISO program" and "certification".
So the thing that happens when you add a single row ball bearing to a shaft like that is you overconstrain it. Basically, the bearing is being used improperly and such use will lead to failure. If the spline fits are sloppy the shaft can wiggle and vibrate. If the shaft spline fits are too tight the imperfectly concentric shaft and bearing fight each other, taking out the bearing. We're talking tiny bits of out of roundness, but it's there, and ball bearings don't like that.
You see, the splines aren't cut in the shaft after heat treat. Steel moves in heat treat. The bearing journal is ground or hard turned after heat treat held between centers. That puts the bearing center of rotation inline with the ends of the shaft, not the splines.
You could support that shaft with two ball bearings, one at each end, and design some clearance into the spline fits. That would work OK sans the clunk you'd get going from drive to reverse. This really would be a poor choice given the lack of lubrication. You'd get spline fretting in time.
Or, you could work your spline fits out to be something like a light tap fit in the transfercase and a sliding fit onto the transmission output shaft , eliminate the bearing altogether and have a decent setup with no bearings to fail in 20K miles.
Another thing that can be done is to not bore a 4" hole in the adapter. give it say, 1/8" clearance around the spud shaft, add a seal to the rear of the adapter to seal on the snout of the HF2AV and pull the seal out of the back of new transmission. This way the splines will get splash lubed with ATF, Exactly as good, experienced Toyota engineers intended, the splines will never wear, and it won't trap any ATF or debris in the adapter.
Just my 2 cents. Good luck with your design.
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- #50
It appears you are experienced with engineering. Perhaps you can comment on my setup.
I have an adapter from Trans to T Case that is open, no bearings. I changed the input shaft on T Case to accept the output shaft of trans.
Not to sure how tight the two spline interfaces are.
Question:
Should I remove a seal on either of both ends to lubricate the splines?
If so I would have to seal the faces of the adapter with a gasket or o Ring.
Thanks
I have an adapter from Trans to T Case that is open, no bearings. I changed the input shaft on T Case to accept the output shaft of trans.
Not to sure how tight the two spline interfaces are.
Question:
Should I remove a seal on either of both ends to lubricate the splines?
If so I would have to seal the faces of the adapter with a gasket or o Ring.
Thanks
Oh, I've been around the splined shaft and billet adapter block a time or two lol.
I think your approach is good, significantly improved over a design using an additional shaft. The tricky part about the way you've done it is the HF2AV input shaft has external splines that are very, very precisely controlled where the input gear presses on. When you assemble that bugger the input gear better not just drop right on. The spline OD should appear ground as that is how the fit works on these. They gear needs to press on, quite tightly.
That's the hard part, the rest is easy.
Yes, you want a seal in the rear face of your HF2AV adapter plate. The same seal that would be in the A343 or A442. This seal seals on the OD of the t-case input shaft. If the transmission has a seal on the output shaft remove it. Seal the adapter to the transmission and the HF2A using the sealant of your choice. i don't recommend O-rings here. O-rings won't tolerate any surface imperfections you may (likely) have. In 10 years when somebody takes this apart for some reason they won't have the right size o-ring on hand. They'll have to figure out what o-ring it is and order it. In all likelihood they won't do that, they'll just RTV it and put it together.
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- #52
Thanks
I will contact you again when I am doing final assembly, if you don't mind.
Do you know about torque converters to flex plate adapters also?
I will contact you again when I am doing final assembly, if you don't mind.
Do you know about torque converters to flex plate adapters also?
Got some work done today mounting the transfer case shifter plate on top of the 8HP75. This will position it the same distance from the back of the block as before. As I mentioned above, my rig has a 1" body lift. That will help, as the 8HP75 is 1" higher off the output shaft centerline than the A343F.
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- #55
Thanks for that. I was wondering what to do!
I used the two rear machined datum features that are on the 8HP. Drilled them out to 8mm, then used 8mm all thread with nuts / washers to set the plate height. The front two locations are some obround bosses that are hollow. Not sure what ZF does with those, but they are on every 8HP I have seen a picture of. Marked and drilled those to 8mm also, then installed all thread. The all thread allowed me to level the plate left/right and front/back, setting the height. Took two tries to get the distance correct from the theoretical bell housing plane on the back of the block. Solid as a rock, should work fine for holding the shifter assembly. Relatively cheap and easy to modify and replace. Oh, and I used press in PEM M10 nuts into 1/8" aluminum sheet.
Just to document this, the distance from the bell housing interface on the A343F to the first row of transfer case shift lever mounting bosses is 529 mm (20.83").
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first time I have seen PEM hardware on a DIY part. Awesome
Loving this thread. Can't wait to get to the 8HP swap in my FJ62 eventually
Loving this thread. Can't wait to get to the 8HP swap in my FJ62 eventually
This thread is fantastic. Thanks for all the information and sharing your hardwork and investment.
I really like the idea of a modern 6 or 8 spd transmission in a Land Cruiser. Having a transfer case adapter will also open the door to a multitude of possible engine and transmission combinations.
I really like the idea of a modern 6 or 8 spd transmission in a Land Cruiser. Having a transfer case adapter will also open the door to a multitude of possible engine and transmission combinations.
I am a Mechanical R&D engineer for a tech company. I design sheetmetal all day with metric PEM fasteners. Kind of second nature for me to design them in.
