6R80 vs 4R70W swap

[77BroncoWag]

Long time since I have been on here so HELLO AGAIN. Finally saved up some funds to get started on my 77. The engine a 5.0 roller that will be FiTech efi soon should be ready in a month.

Now the tranny swap. 4R70W vs 6R80. What am I looking at price wise have seen rebuild 4R70@ in the $3500 range and finding several 6R80 that need to be rebuilt in the $500 range.

so I will need adapters and controllers who is the best for the $$$$. What else will I need?


fire away and thanks for the help.

 

[MonsterBIlly]

I cannot speak on the 6r80, however I did the 4r70w. I like it. It sees to be very strong. I am pretty hard on it and it is behind a 408.
I used the us shift controller and its pretty nice. I had a little bit of a hard time getting it tuned correctly. I still have a little to do, but I am happy with it. I bought it off of CL for 350.00 then had it rebuilt before I installed it. The rebuild was 900.00. The controller was about 600. So I'm in it totally for 2k. I didn't need any adapters because I had already decided to go with an atlas transfercase.

 

[SSDDBRONCO]

You might find this thread useful

https://classicbroncos.com/forums/showthread.php?t=312439

 

[rguest3]

The earlier 4R70W Transmissions did come with a Small Block Ford Bell housing, so pretty much a direct bolt on to your 5.0L Motor.

The 6R80 only has been available with a later Modular Motor Bell housing. You will need an additional Bell Housing Adaptor for this install to your 5.0L Motor.

You would need a Controller for both, so that's about the same. (Quick-4 or Quick-6)

Both will need an adaptor for the Dana 20 Transfer Case. Neither need an adaptor with an Atlas.

 

[distended]

You might find this thread useful

https://classicbroncos.com/forums/showthread.php?t=312439

I've been meaning to give that an update. I will in a few days with pics.

I decided to go with the 6R80 especially after the advice from nvrstuk along with reading his build thread and Broncobowsher. Received my used 6R80 last week. I ordered the SpeedGems adapter and they have a combo for it and the US Shift Controller, the adapter kit came today.

 

[nvrstuk]

rguest3

The 6r80W needs an adapter for the Atlas. This is what I used.

50-3900
Ford 6R80 & 10R80 to Atlas 31 spline input transfer case.

$440.91

 

[hossbronco]

Received my used 6R80 last week. I ordered the SpeedGems adapter and they have a combo for it and the US Shift Controller, the adapter kit came today.

You'll have to keep us updated on the Speed Gems adapter. I've been planning to use it for several months, but I'm waiting until my stroker comes in to buy it. They've been making slight tweaks to it and are about to start their third production run here in a couple of weeks.

I second the comment on the adapter. I have the 6R80, adapter, and Atlas Pro 3.0. The adapter is definitely required.

 

[nvrstuk]

The D20 adapter can be trimmed and then it can be used for an N205 also I was told by Atlas.

 

[rguest3]

I have an Atlas behind a 4R70W. The Atlas was ordered to specifically go behind the 4R70W.

The only mod to the trans is the output shaft is trimmed to be even with the end of the case. No other Adaptor needed.

 

[nvrstuk]

hossbronco-

Do you know what the "tweaks" have been to the SpeedGems adapter? I'm always interested in how stuff evolves.

thx

 

[bigmuddy]

I have an Atlas behind a 4R70W. The Atlas was ordered to specifically go behind the 4R70W.

The only mod to the trans is the output shaft is trimmed to be even with the end of the case. No other Adaptor needed.

What was special about the Atlas that you purchased? I have a 3.0 that I plan on putting behind a 4r70w and thought it was more or less a direct fit?

 

[hossbronco]

I know early on they had some issues with the starter, though I'm not sure if it was the starter itself or just placement. They currently use the Powermaster 9604 for automatic transmissions. I was also told that in the second run an engineer changed something that made it not as good as the first run. Again I don't have specifics. I assume that will get corrected on the third run. They also recommended I use Pioneer FRA-210 or similar for my neutral balance flexplate.

 

[Broncobowsher]

If I were plucking an Explorer 5.0 I would just use the 4R70W that comes with it.

These days, just picking a transmission to swap in, 6R80 would be my pick. The gearing is better and it is newer. You can pick up a newer, fresher transmission easier that is less likely to need a rebuild than a 4R70W.

The newest 4R70W that fits is now 20 years old. Back when I first did it they were as new as the 6R80 is now.

 

[rguest3]

I don't think the Atlas was special at all. Just correct Spline Count. Just a slight mod to the Output Shaft of the 4R70W.

 

[rguest3]

Look up the Atlas transfer Case and go to the Tech Vault and look up your transmission and what adaptor is needed.

No adaptor for the AOD/4R70W. New Tail housing for the 6R80/10R80.

 

[nvrstuk]

bigmuddy, there's nothing special about the Atlas to bolt to a 4r except buy the Atlas that is made to bolt up to a 4r.

You will probably have to trim appr. .050"-.125" off the tailshaft but maybe not. I did a couple times but I was bolting it to Klune's and Titans. On my 6r and 3.0 Atlas ProCase I had to taper the splines on the 6r output shaft appr. .025" more to allow the Atlas with the adapter to bolt up tight to the 6r. Super simple.

 

[Quick & Dirty]

4R70W uses the standard round bolt pattern, 31 spline that Ford used for most full size T-cases from 1973 up to 20?? Need an adapter for the Dana 20, but not for an NP205. Chain drive cases are too wide for a Bronco frame. Atlas works with the standard Ford adapter housing.

Transfer cases factory mounted to the 6 and 10 speeds bolt directly to the transmission with no separate housing so those transmissions will need an adapter for an older T-case.

 

[77BroncoWag]

does it mater if its from a 2wd or 4wd?

 

[nvrstuk]

Yes, 4wd only. Look at pics of an F150 2wd 6r trans

 

[Broncobowsher]

does it mater if its from a 2wd or 4wd?

4R70W, 2WD will work only if doing a full rebuild to install the correct output shaft.