Jezza's Ford 6R80 Transmission Swap

This is an awesome project. After driving my dad's 2015 F150 with a 6r80 I was impressed with the transmission. I thought that it would do well behind the 4.0, but couldn't put in the leg work to get it done.

Best of luck, I'll definitely be following this build.
 
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86CJ7 said:
This is an awesome project. After driving my dad's 2105 F150 with a 6r80 I was impressed with the transmission. I thought that it would do well behind the 4.0, but couldn't put in the leg work to get it done.

Best of luck, I'll definitely be following this build.
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I'm working away on it. I have some hard parts on order for the transmission. Bigger progress will be made when I receive the Atlas.
 
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So, I'm a a point of decision. Originally I was going to put this entire unit into my 2002 and had purchased a flexplate and starter for the 2002. However, now it is going into the 2005 LJ and that uses a smaller diameter flexplate as well as a different crank pattern. The difference is major as the 2002 is 13.75" and the 2005 is 11.5" or so. The other issue is the 6R80 torque converter fits inside the larger early flexplate, and does not fit inside the later one. Thus my adapter plate would probably end up being twice as thick for the later flexplate. I would however be able to use that flexplate for the crank pickup. So, I need to make a decision whether to continue using the early flexplate and make a crank trigger wheel for the front of the engine, or the later smaller flexplate and deal with a thicker adapter plate?

20221004_145052.jpg
 
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I noticed the flexplate size difference between the 32rh and 42rle transmissions the other day and was wondering what impact this would have. My thought on this (which may or may not be correct due to my lack of in-depth knowledge on this) is that using the larger diameter flexplate is the way to go along with one of these pre-existing components to solve the the crank pickup issue:
https://hesco.us/products/30791/40l...6edr-2005-06-rh-dampersensor-kit#.Yz5XB6RlDCg

https://hesco.us/products/30791/40l...crank-sensor-kit-91-04-hes9199ed#.Yz5XG6RlDCg

I think that the thinner the adapter plate the better (maintaining a minimal required thickness for adequate strength of course).
 
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Jezza said:
So, I'm a a point of decision. Originally I was going to put this entire unit into my 2002 and had purchased a flexplate and starter for the 2002. However, now it is going into the 2005 LJ and that uses a smaller diameter flexplate as well as a different crank pattern. The difference is major as the 2002 is 13.75" and the 2005 is 11.5" or so. The other issue is the 6R80 torque converter fits inside the larger early flexplate, and does not fit inside the later one. Thus my adapter plate would probably end up being twice as thick for the later flexplate. I would however be able to use that flexplate for the crank pickup. So, I need to make a decision whether to continue using the early flexplate and make a crank trigger wheel for the front of the engine, or the later smaller flexplate and deal with a thicker adapter plate?

View attachment 364585
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Why would the adapter have to be twice as thick? I'm not understanding that. I would find a way to put the crank trigger in between the engine and transmission personally if you have the room for it.
 
RustyAutoholicGuy said:
Why would the adapter have to be twice as thick? I'm not understanding that. I would find a way to put the crank trigger in between the engine and transmission personally if you have the room for it.
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I believe that the extra thickness is needed due to the diameter of the torque converter being greater than that of the smaller flexplate.The 6r80 torque converter has a 11-3/8" bolt circle. The adapter would have to be thick enough to allow the torque converter to clear the flexplate and provide adequate mounting bosses.
 
86CJ7 said:
I believe that the extra thickness is needed due to the diameter of the torque converter being greater than that of the smaller flexplate.The 6r80 torque converter has a 11-3/8" bolt circle. The adapter would have to be thick enough to allow the torque converter to clear the flexplate and provide adequate mounting bosses.
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Yep, and clear the trigger wheel on the flexplate.
 
I made some decisions and have some good and bad news. I am going to run the early style flexplate with the JTEC crank pattern. The later NGC flexplate was simply too small to be usable. The spacer would have had to be 2 plus inches thick. The good news is the early flexplate fits over the 5.4l torque converter entirely with no cutting. So, that will be the converter I will use. The bad news is the 4.0 starter nose cone stabs right into the bellhousing flange on the 6R80 transmission. I think the fix there will be to notch the bellhousing on the transmission to allow the starter to clear. I'm still drafting and taking dimensions. I'm determined to get this right the first time.

20221010_175206.jpg
 
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Following.

As to the trans temps--the 6R80 is controlled with an internal thermal bypass. On the F150 applications, that thermostat opens at 195° IIRC. So the normal range cold; 50°, normal to mid is 81-225°, and hot is 275°. I havent seen it, but supposedly there is a thermostat delete you can do and the trans will run much cooler (170°ish).
 
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tworley said:
Following.

As to the trans temps--the 6R80 is controlled with an internal thermal bypass. On the F150 applications, that thermostat opens at 195° IIRC. So the normal range cold; 50°, normal to mid is 81-225°, and hot is 275°. I havent seen it, but supposedly there is a thermostat delete you can do and the trans will run much cooler (170°ish).
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I was aware of the thermostat, I wasn't aware of the bypass. It looks like an easy to make part on the lathe. I wouldn't mind having a thermostat if it opened at 140 or so. 195 seems high to me.
 
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I am planning on cutting the adapter plate tomorrow unless something more important comes up instead. So far I have roughly modeled the block and transmission and accurately modeled everything in between. The case spacer is 0.700" thick right now and the convertor to flexplate spacer is just under 1.5" mostly due to the centering hub height. I still need to model a dust plate to keep the chunks out , but other than that I think it is 90% or closer.

4.0 Bellhousing Final With Block v27.1.jpg


4.0 Bellhousing Final With Block v27.2.jpg


4.0 To 6R80 Final Rev 2 v5.1.jpg


4.0 To 6R80 Final Rev 2 v5.2.jpg
 
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The 6R80 to Atlas adapter came in today. I spent some time mocking up the trans and Atlas. Everything bolted up good and assembled smoothly. I also used a cut up bellhousing I had laying around to mock up the crank sensor. I have a plan worked out for that, hopefully it works.

20221028_182118.jpg


20221028_182216.jpg
 
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Jezza said:
The 6R80 to Atlas adapter came in today. I spent some time mocking up the trans and Atlas. Everything bolted up good and assembled smoothly. I also used a cut up bellhousing I had laying around to mock up the crank sensor. I have a plan worked out for that, hopefully it works.
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What’s the chances of this also being a kit? Or at least selling the adapter plate?
 
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Josh300 said:
What’s the chances of this also being a kit? Or at least selling the adapter plate?
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It's a definite possibility. I still have a few things to sort out. Ultimately it is not a simple swap requiring changes to the transfer case, crossmember, driveshafts, PCM tuning, wiring etc. I can only imagine interest would be very limited.
 
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You're making good progress Jezza, everything looks to be coming together. I'm looking forward to seeing the finished product. I'm definitely interested in getting one of these as a kit, as my project is going to require a few custom options regardless (custom skid, driveshafts, etc). I think that the 6R80 is an excellent transmission and should perform very well behind the 4.0.
 
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