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4r70w swap questions

TheLimeRanger

Sr. Member
Joined
Sep 5, 2001
Messages
749
okay guys, I know this topic has been swatted around pretty good but I want to make sure I have all my ducks in a row. Ive searched through all of the posts I could find on here, please tell me if I'm missing anything.

currently have a 74 with a stock 302 and a c4 with a j-shift transfer case. one day I'm hoping to get my explorer motor in the truck, but for now I want to drive the darn thing and I'm getting impatient!

this is what I think I need, please tell me if I'm missing anything:

4r70w from an AWD explorer
advanced adapters adapter kit
twin stick kit for a j-shift to fit the adapter
cross member
baumann controller
tps sensor for the carb
lokar linkage kit to adapt the column shifter to the new tranny
narrowed and lengthened drive shaft for the front diff
shortened drive shaft for the rear diff

am I missing anything? can I use my original starter or do I need a different one? a tranny shop near me quoted me $2500 on a full rebuilt tranny with the adapter installed and a hi-stall converter, also includes the tranny, I would not have to supply a core. does that sound reasonable? do I need to install a body lift to do this swap?

thanks in advance
Scott
 

Gpops

Jr. Member
Joined
May 17, 2013
Messages
65
What are you planning to do for transmission lines? Also might want to consider axle gearing to get a good final drive ratio.
 

bronconut73

Bronco Guru
Joined
Aug 7, 2012
Messages
9,916
Uncut and original means small tires.....
Sooo if you have stock 4.11 axle gears and 28" tires you may be good.
Or if you had the rare stock 4.56 axle gears you could prolly run 32's.

Keep us posted.

Don't forget that you "can" bolt an NP-205 to the back of that tranny, no adapter needed. Save some money on the adapter but you have to buy or make a transfer case mount for the 205...
 

sanndmann3

Bronco Guru
Joined
Jun 13, 2007
Messages
1,774
yep, that is an option. 205 is SO much stronger than the 20. Too bad low range leaves something to be desired...
After busting 3 D20s, I went the 4R/205 route a year and a half ago...
 
OP
OP
TheLimeRanger

TheLimeRanger

Sr. Member
Joined
Sep 5, 2001
Messages
749
I knew I forgot to mention something. I have 4.11's and a 31" tall tire. Will the 4r70w work for what I am running? This is going to be a street driven truck only

Thx!
 

spap

Contributor
Bronco Guru
Joined
Jan 2, 2010
Messages
2,458
2200 at 65 mph. Just over 2300 at 70. Depending on the motor you should be fine
It s a great trans
 

DirtDonk

Contributor
Bronco Guru
Joined
Nov 3, 2003
Messages
47,355
Yep, running 31's and 4.56's here. Love it, but will likely go up to 4.11's at some point to see if I like it even more. I think I will, but I'm in no hurry and would like to play around off-road with the 4.56's and Detroits in there now. Should be fun!

Stock converter is an excellent all around setup. Make sure that's really what you want to change before spending on the new high-stall version.

Stock starter "should" work, but there have been instances of them not quite playing friendly with the new flex-plates. Doesn't seem to be any consistency yet, so hard to say what's up. May be the individual flex plate offsets? Slightly different, but can still work with the trans?

The stock C4 flexplate does not work with the 4R70, does it?
And what model C4 converter do you have now? Small or large bolt pattern? Just wondering if either one is compatible, but I think I remember you have to swap out the flexplate no matter what.

Wait for flexplate-fu gurus to confirm or deny that vicious rumor however...

Paul
 

Green_Bastard

Full Member
Joined
Jan 4, 2014
Messages
257
The stock C4 flexplate does not work with the 4R70, does it?
And what model C4 converter do you have now? Small or large bolt pattern? Just wondering if either one is compatible, but I think I remember you have to swap out the flexplate no matter what.

Wait for flexplate-fu gurus to confirm or deny that vicious rumor however...

Paul

According to many things I've found during my research, the original C4 flexplate works just fine. This thread has some good info. Take a look at post 51.

I hope its correct because I just ordered one for my build.
 

sanndmann3

Bronco Guru
Joined
Jun 13, 2007
Messages
1,774
Yep the C4 flex plate works with the 4R70W. I lined up my original plate with the Explorer unit and tooth count, offset and torque convertor bolt pattern were all the same. only difference was the imbalance (28 vs. 50).
Explorer starter also works well but had modify the wiring so the starter wouldn't hang...
 

onebadd73

Sr. Member
Joined
Sep 22, 2003
Messages
376
Loc.
Moreno Valley, Ca.
Im still working on my install..here's what I paid:

Used 4R70W out of a 96 explorer $400.00
US shift Controller plus harness and TPS for Holley carb $900.00
trans oil lines ebay- $125.00
NP 205 $100.00
Rebuild kit for NP205 Ebay- $90.00
Twin stick for NP 205 $170.00
Shift kit for trans Ebay- $115.00
Trans deep pan Ebay- $135.00
Lokar shift linkage kit to mate to column shifter $ 85.00
Metal for custom crossmember $20.00
New mini starter ebay - $50.00
B&M trans cooler- $90.00
Total $2165.00

But I sold my old C4 for $700.00
Dana 20 $150.00
Dana 20 twinstick $125.00

Total $975.00

Actual cost $1190.00

Yes you can use the stock starter and flex plate. You don't need a high stall torque converter. I have a 2" body lift on mine but its not needed. You also need to figure out the dipstick, either buy a Lokar type or bend the explorer dip stick to clear the fire wall.
 

onebadd73

Sr. Member
Joined
Sep 22, 2003
Messages
376
Loc.
Moreno Valley, Ca.
By the way if you can find a Ford explorer from 97-2001, you could snag the motor, trans, and all the electrical harnesses needed to shift the tranny and not have to spend the $900.00 on the US shift controller and TPS sensor. I just found a 98 Explorer for $600.00. with a 5.0.

Frank
 

ralls

Full Member
Joined
Mar 17, 2009
Messages
231
Loc.
Andalusia
Agreed on complete explorer. So many little things can be harvested. I understand your desire to get on the road with the carb,but you will save alot of money from unnecessary purchases if go ahead with the explorer efi. I bought my 2wd 5.0 explorer for 600 with a blown tranny. Bought a 70k mile awd trans at junkyard for $300. Did the harness myself and paid efi guy to tune. Without a doubt best time and money spent. I'm running 5.13 with 35"s. 2000 rpm at 55.
 

sykanr0ng

Bronco Guru
Joined
Aug 11, 2014
Messages
5,363
Yep, running 31's and 4.56's here. Love it, but will likely go up to 4.11's at some point to see if I like it even more. I think I will, but I'm in no hurry and would like to play around off-road with the 4.56's and Detroits in there now. Should be fun!


Paul

Have you considered 4.27/4.30 gears?
Split the difference and lose less on either end.
 

duffymahoney

Contributor
Bronco Guru
Joined
Apr 26, 2015
Messages
2,556
I am planning on 32.8" tires with 4.11. We shall see how highway rpms go and how the brick likes driving down the highway at around 2k rpms.
 

ZOSO

Full Member
Joined
Jan 25, 2003
Messages
345
I am planning on 32.8" tires with 4.11. We shall see how highway rpms go and how the brick likes driving down the highway at around 2k rpms.

I'm running 33" bfgs so 32.x" and 4.10's with the 4r70w. It runs nice at 70 and 2200rpm. That's with a 351. That being said it needs more gear.
 

DirtDonk

Contributor
Bronco Guru
Joined
Nov 3, 2003
Messages
47,355
Depends on how your engine likes that rpm torque-wise duffy. If you're injected and tuned well, it should plug along nicely even with a 302. If you're carb'ed and not cammed, or otherwise more powerful than stock, it might be ok, but most likely will struggle a bit in overdrive on anything above level.
It's a battle between air resistance, gravity and rpm. If you can get into your particular engine's happy place before the aero is just too much, it can work well.

My own would pull 2000 rpm at freeway speeds just fine. My old '71 would not be happy I'm sure. It likely would have done the flatlands fairly well, but the first hill it encountered below 2700 rpm or so you'd have to downshift and force it into the wind and gravity. It was never really happy the the lift and tires and the 4.11's, but now that I'm running a stock Explorer setup, I'm sure I could "lug" it down all day and it would be fine.
But we'll see...;D

Paul
 
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