swapping 1998 V8/4R70W/4406 into 1999 SOHC 2wd | Page 3 | Ford Explorer Forums - Serious Explorations

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swapping 1998 V8/4R70W/4406 into 1999 SOHC 2wd

Brother from another mother!!

Lucky!! Looks awesome and all that green grass too!

How does the dana 20 do behind the 4r70w?
I’ve only ever used the np205, 1354 or 4406

My place this am

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Works like it should. Got twin sticks so I do front digs when necessary. I think I've only done it once in about 10 years since the EFI swap from the old 289/c4. If the adapters weren't so expensive, it would be easy for everyone to use D20. One the other hand, there aren't many just laying around. 5 years ago, I had 4 brought and given to me by different folks at a bronco event. Now a case that needs rebuilt will bring $300. I also have a "cold duck" that just the range box portion (top half of the D20) with an adapter and shaft to go between the transmission and the T case for a doubler.

Just a few pics of todays progress.





2nd picture reminds me of that Studebaker in O.C and Stiggs

Makes me want to put another lift in outside in the grass!! Well done! Did all the body mount bolts play ball?

output shaft is changed! All clutches looked really good. Slapped it back together and I’ll get on that sleeve installation after lunch…pending any work related stuff that may happen.


Keep that speedometer drive gear (tan plastic bit) they are getting harder to find

Keep that speedometer drive gear (tan plastic bit) they are getting harder to find
I don’t even see a speedo drive gear. That thing that’s on the shaft is some kind of bumper or stopper or something.

Installing the Sonnax 76890-01K 1-2 accumulator sleeve kit…


I didn’t spend the money on the tool. Not doing that! You have to seal the sleeve in the bore, so I got some permatex sleeve sealant. Instructions call for Loctite 609, but it’s all the same. I just made sure I had a good line all the way around to seal it off.


You can see below that the sleeve is multiple pieces. Do not just drop a socket in the hole and start driving with a hammer. It will most likely bust apart.


So I used a 1-1/4” socket upside down to get more flat surface contact on the top lip to drive it in. It went in pretty smoothly.


You have to be sure to line up the holes when driving it in.


The big bore sleeve slid in by hand because I had honed the bore quite a bit.





And its ready for springs whenever they arrive today.

Ahhhhh sorry when I zoomed in I see that

Springs are in. But I scuffed the reverse servo piston cap and now it needs to be replaced. The piston itself was questionable to start with. Didn’t seem to be squeezing into its bore as tight as I like it. So we wait some more. In the meantime, I’ll figure out if the VB needs to be cleaned up. The fluid doesn’t look to bad that came out of this thing, so…??



So I pulled an under-hood harness from the JY the other day. I already had a 2000 wiring book, but I went ahead and got the 98 and 99 since I have one of each of those two. I wanted to compare the pcm connection and C115 connections to make sure the 98 engine harness I’ve got plays well with the 99 under-hood harness. Turns out both plugs are exactly the same.



careful here some v8 use some slightly different connections
look in your book it should list separate c115 for v6 and v8
only SOME of the v8 came with the other connector (adding confusion)
Also the 4x4 control module, NSS wire from DTRS to GEM module is not present on v8 models (maybe mute point since you are going rwd to manual shift)
Also instrument cluster connection for the tachometer is different v6 to v8

There are many changes at the C139 connector sohc vs v8
the alternator charging, starter, and ac wiring differs quite a bit between the two

Still a simple swap, as easy as they get what you are doing 99 v8 into a 98, about 95% plug and play

nice work thus far! With engine out be sure to change power steering high pressure hose, throttle cable, and drivers engine mount

So, to be clear, I'm swapping in the 5.0 under-hood harness (which I pulled from a 99) and the 5.0 engine harness from one of the 98s. The C115 connection that ties to the under-hood harness is pinned the same. I think I know what connection your talking about, but its not the 139. That's the windshield washer pump according to the book. I know I've still got the starting/charging harness on the 4.0 setup waiting to be pulled. I don't remember there being a similar harness in the 99, but maybe I should go back to the JY and pull that one too?

Sorry I would have to get my books out they change the name of the connectors explorer vs ranger and I bounce around a lot
However the basics are same v6 to v8
Changes to alternator charging harness as the v8 the big yellow w white and small green/red travel through the c115 plug on the v6 they do not

Oil level sender in the v8 oil pan, v6 does not have

Tachometer signal has to be changed at back of instrument cluster, you move the ground wire from one connector to the other

The ac system is wired slightly differently v6 to v8, routing changes for the high and low pressure switches

It will become Clear once you lay things out under the hood
I hope I am not muddying the water
I do many 5.0 swaps and they are all slightly different lately I have been doing a lot of later models 02-04 and mostly rangers and sport tracs. It has been a long time since I did a v6 to v8 gen ii

LOOKY WHAT I FOUND IN THE BACK OF THE DONOR MOUNTY! I was preparing to go to the JY this afternoon when I get off work to get one.


And I got the rebuilt torque converter in the bell, and bolted the trans to the engine. I’ve got to get the 4wd adapter off another transmission to be able to bolt the t case on.


There was some sun damage to the starter exciter wire. So I spent a few minutes repairing that.


And then wrapped up the repair and some places on the under-hood harness that needed redone.


Here’s the C125 connection. Top is the battery/starter harness. The donor Mounty had the message center, so this harness has the wiring for the oil temp/level sensor. The explorer under-hood harness from the JY didn’t have those wires. Then you can see the other end of the harness had the sensor connection cut off. Yay. Guess I didn’t need it anyway?!



Did I mention one of my Eng/trans harnesses got cut in two? Pretty sure it was rats. I thought it would be a quick job just to splice all the wires back together using some extra harnesses I’ve got. But when there’s 14 or 34 wires in the bundle all the same colors…. #orange. …you have to pull the wiring book out and check your work!…before you do the work!

(This has me wondering if there’s a Bluetooth trans controller on the market to make this link?)



This is where it’s going to sit till Monday. Leaving town to go to the MILs for the weekend-yay. 😞


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Rats!!! Sheesh
Honda makes a electrical wrap with red pepper in it to keep rodents away from wiring

Nicely done all downhill from here lol lol
Sometimes there is an air suspension wire in that connector as well… a few of those buggers are not needed

Plan to beef up the trans mount the stock v8 unit is kinda puny when hanging the 4406