4R70W Build Diary by Spdrcer34 | Page 2 | Ford Explorer Forums - Serious Explorations

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4R70W Build Diary by Spdrcer34

Well, I got a hold of the seller finally.

He said he sent me a 'High Energy' Overdrive Band, instead of the Kevlar one I bought. He admitted that he knew he was shipping me a cheaper product. And then he tried telling me that I would be better off with this High Energy band over the Kevlar I paid for. He could tell I was getting irritated with him, and he finally agreed to refund me once he received the band, and he will refund me the shipping that I spend to get it back to him. We will see.


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...I found the MAJOR failure on this transmission...

The Mechanical Diode failed, causing the ring inside of the assembly to break into 4 pieces. It also caused the retaining ring to deform. Pics to come tomorrow.


Cool Ryan, you are doing great there. Kick me for not getting into mine earlier.

I bought a new reverse drum and mechanical diode assembly for about $140, they are still on eBay from a good company, fast shipping IIRC.

Have you addresses the input shaft and removing the forward drum yet? I needed to plan for that, and to drill the extra holes into the direct drum. I was putting that off, plus I bought a used late car VB to perform the "J" mod to. I'll get to mine once I take care of my 99 5R55E that died last month. Regards,

Great work it makes me excited to get into my core classes at school because I will spend two months on auto tranny's. And they go over full automatic rebuilds and we dyno them after to test. :) Excited to do auto tranny work!

Pics as promised...




And here is the case I primed and painted it.


Have you bought the Sonnax spiral locks for the mechanical diode yet? That is supposed to solve those OEM snap rings failure issue. I think they do okay under a certain rpm like 5000, but somewhere above that the centrifugal forces sling the snap rings off.

Yeah, I bought a 3 pack. I will be building a new tranny for my X this spring, and I am going to help someone here build theirs too...


Yes, these 4R's are not a bigger deal than the AOD's I was used to in the 90's. I just hadn't built one for so many years.

It's back together sitting on my bench....

I had one thing go wrong after the other....

1) There are 2 LARGE snap rings in the case. The one with the legs that are turned up is easy to place. The FLAT one though....it took me DAYS to find out where it went. It wasn't until I saw a video on YouTube, and that FLAT snap ring was the VERY FIRST thing he put in the case. It's more of a temporary support for the Reverse Band than anything. The transmission can be assembled without it, and nobody would know the difference. Its not critical, but I put it in there anyway...but that meant the WHOLE trans had to come back apart...luckily I didn't install the pump.

2) After getting the flat snap ring in the case, I measured for the selective washer/ case bushing at the pump, and I kept getting 1.592...to 1.599 for a measurement, the thickest selective washer would compensate UP TO 1.580 or something like that I was a bit too short in the whole assembly. Then I started to look at the old parts, and I realized that I had 8 Torringtons sitting on my bench. There should have only been 7. I looked at them all, and sure enough, there were 2 #8 bearings. Appearantly I forgot to put the #8 bearing against the direct drum after I sized the solid seals, and put the output shaft inside of the direct drum. So now the WHOLE assembly had to come apart...again. I put the bearing in place, and it raised the whole assembly up enough that I was within spec to use the Green washer.

3) While putting the OD servo together, I got the kerf cut seal stuck in the snap ring groove. I broke the seal in my attempt to remove the crooked piston. And to make matters worse, I also managed to break the snap ring itself. So another trip to the transmission shop to buy the parts needed to fix this mess, and $5 later, they had me hooked up with a new snap ring, and a kerf cut seal. $5!!!!

4) I must have installed the valvebody 5 or 6 times...everytime I was ready to torque it down, I realized I didn't check something, or something was missing...there was an extra 10mm bolt...little things like that....

I was able to fab up some pump alignment/installation pins, using 4.0L OHV fuel rail bolts...grind down the shoulder, and you have an alignment pin for the pump! They are PERFECT too. The External Torx is small enough that it's not in the way, and you don't have to use Vice-Grips to pull them off....pics will come later...check the time I'm posting this...I just finished and now I'm headed for bed. I have to work in the A.M.

Now I have the tranny in the shop, waiting for me....

I may not get a chance to install it until NEXT weekend though. We'll see.


Very good Ryan. The first one is always more stress than hard work, there are so many parts to go somewhere special. You got it done.



Modified 4.0L OHV Fuel Rail Bolts, shaved down to turn them into Pump Alignment pins:





After having the valvebody apart, and back together a half of a dozen times....THIS is what it looked like just before I sealed it up with the pan...


I had a few extra minutes, so I customized the case....


And this is what it looks like sitting on my bench RIGHT NOW....



Here is a good before and after comparison:



...well, I got off work at 7:00pm, and after fighting the torque convertor for 30 minutes, trying to get it to seat in the pump...then I went to plug in my work lamp, the bulb blew out......and after about 2 hours of lifting, and adjusting my transmission jack, I got the transmission bolted to the block. By that time it was 10pm, and I had to call it a night. Tomorrow, or Monday I will get it all in, and take it for a test drive.


It is in ....it drives....


Now I have the O/D Off light flashing at me. I scanned it and it gave me P1746 Pressure Control Solenoid A Open Circuit.

The Solenoid is BRAND NEW. So I think it may be the 'hard wire' connection. So the pan has to come down....now I have to go buy a brand new, clean drain pan so I can re-use the $8.79/quart ATF that is in there....

It shifts fine through all gears, goes into OD, torque convertor locks up perfect @ about 45mph.

The 2nd gear shift is hard. The O/D Off light starts flashing in ALL gears after about 10 seconds. Even if I leave it in Park, and don't move...same with Neutral....

Anyone else have any other ideas?


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I dropped the pan, and the EPC solenoid wasn't plugged in all the way...

Clicked it in place, put the fluid back in there, and no more flashing O/D!


Shifts perfectly....not too hard going 1-2 like yesterday...

Now I only have the P1451 (??) Evaporative Circuit CEL....I have to check that out..but I had it before the tranny was rebuilt...