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4R70W rebuild

grammer9

Contributor
Newbie
Joined
Mar 1, 2016
Messages
43
Loc.
Vacaville
Hey guys, i’m getting ready to take my 4r70w trans in to
get rebuild. My question is: Is there anything outside of a routine rebuild i should be telling the transmission tech to do while he’s got it opened up. Both motor and transmission are out of a 98’ ford explorer 4wd with 150k on it. I plan to put this both in a 76’ build i’m working on. Bronco will be a weekend fun rig for the family an maybe some moderate wheeling here an there, light trail and snow run. All cool stuff you can do with them. Nothing to hardcore.
Also what’s the goin rate $ for the transmission to get rebuilt.
thanks
 

sanndmann3

Bronco Guru
Joined
Jun 13, 2007
Messages
1,774
You got the trans with the better internals (98 and after), so that is a good start. Might want to explorer using better frictions and steels. Red Alto is what I used. you can also add a friction plate or 2 to the drum ( can't remeber which one)
this was a good resource when I did mine...
https://www.tccoa.com/articles/tranny/transmission/
 

spap

Contributor
Bronco Guru
Joined
Jan 2, 2010
Messages
2,455
Check out info on getting the j mod done
 

fordguy

Contributor
Bronco Guru
Joined
Jan 23, 2005
Messages
5,493
paid 1200 for mine with torque convertor, he also installed the aa adapter.
 

needabronco

Bronco Guru
Joined
Jul 2, 2004
Messages
6,411
Loc.
Prescott/Farmington
I would suggest not using the red clutches. They are known to not handle heat as well. I used Raybestos blues in my 48re that has seen a lot of heavy towing and heat and still shifts like new.

You can add a clutch hear and there, but adding more clutches means thinner clutches and steels which while they hold more pressure, they can warp easier with heat and the clutches delaminate faster.

Definitely add some sort of shift kit to bump line pressure and to correct any wear issues in the valve body. This was I'll likely yield you the best benefit.
 

needabronco

Bronco Guru
Joined
Jul 2, 2004
Messages
6,411
Loc.
Prescott/Farmington
I wouldn't be afraid of rebuilding it yourself either. Automatic transmissions are actually fairly simple when you break them down. You may have to buy a couple of tools or use some creativity, but as long as you follow the rebuild manual and do the air checks you cant really screw them up.
 

fordguy

Contributor
Bronco Guru
Joined
Jan 23, 2005
Messages
5,493
btw, i bought the sure cure kit and had it installed along with the clocking lever for shifting (by lokar)
 

gnsteam

Contributor
Bronco Guru
Joined
Jan 29, 2010
Messages
3,506
Loc.
Lincoln NE
I wouldn't be afraid of rebuilding it yourself either. Automatic transmissions are actually fairly simple when you break them down. You may have to buy a couple of tools or use some creativity, but as long as you follow the rebuild manual and do the air checks you cant really screw them up.

I couldn’t agree more. I’m going to give it a try, and I have no experience. Take a look at the how to video series at, Transmissionbench.com.
 

needabronco

Bronco Guru
Joined
Jul 2, 2004
Messages
6,411
Loc.
Prescott/Farmington
In my experience the hardest part of the rebuild is the R&R. Once on the bench they are easy. Just make sure you have plenty of room to spread things out and stay organized. I prefer to disassemble, clean, and reassemble in sub assemblies in the order they come out of the case. Lay it all out and double or triple check your clearances and lip seal when it goes back together.

One member suggested years ago to lay it all out on a sheet of plywood to give you plenty of room and to stay organized. I do it on a 4x6 work bench and have enough room. It takes about a case of brake clean to clean everything and for the valve body. Don't use rags for a final cleaning as the lint can clog passages in the valve body and case. I use lint free paper towels like the blue Scott towels. Soak the clutches in ATF before assembly and use ATF to lube the seals when you install them.

The valve body is the most complicated part, but as long as you take it apart in order and stay organized it isn't very hard. I like to take pictures of everything as it comes apart, which really helps if things get out of order or it's a few days between work.
 
OP
OP
G

grammer9

Contributor
Newbie
Joined
Mar 1, 2016
Messages
43
Loc.
Vacaville
Can’t thank u guys enough for all the good info. I might just try an go for it myself. Save myself some change. As for the “j” mode: Are most of u guys doin this? Is this something i should do for sure while i have it opened up.
 
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