4R70W Upgrades for towing - Request for assistance.

[CDW6212R]

That's good, I found 2-3 versions of the same information. Some was harder to follow, but I think they all covered the same details. I made notes based on the online stuff, or what I might have also saved to my PC. Your own notes will be easier to work with, because you will have done most of the long thinking about each hole or step, during making the notes.

Ideally you or one of us will get the process done soon, with the two common accumulator springs, and work out which hole sizes work best for the 4R in these trucks.

 

[transman304]

Determining the correct orifice size and to what components is important for sure. You also have to remember that the PCM is adaptive to your driving style by monitoring time to fill and when to release components. Each event must fall into preset PIDs in order to learn. This is all based on a OEM default programming. If you happen to make a orifice to large on a certain circuit you stand the chance of flooding a solenoid or clutch pack bleed. Automatic transmission operation is simply a controlled leak.
Brad

 

[CDW6212R]

Very true, people have said many times that they think a simple PCM reprogramming can equal any hard parts changes, or VB parts. I obviously disagree with that, but the computer does operate based on expected fluid control functions, parameters etc. So we do need to stay within ranges of hole sizes etc, so the PCM can handle it. That's another reason to be conservative to begin with, to not jump the biggest hole sizes possible.

 

[Fredness]

Been tuning with SCT since 2005, and I can confirm.
I prefer to service trans (Fluid, Filter, Bands adjusted - if possible, replace the EPC/TCC/Shift solenoids), beef the VB, then tune.
My 5R55E went for 80K+ this way until the factory TC (with 178K+) decided it was done playing. Now it gets the 4R70W, problem solved.

 

[CDW6212R]

Have you browsed through the Sonnax 4R70W section they have? I got into it a few years ago, and ended up getting their upgrade drums etc, for two of my bigger projects. I'm going to need to build those two first, one my black truck the 4R lost 3rd/4th gears, and my LSC I'm going to convert the AOD to the 4R(and PCM) before an engine swap.

The 4R for my Lincoln will have the AOD gearing, the AODE planetary etc, to keep the close ration gearing. I already had a new AODE sun gear shell in an AOD I built, so I have to take that apart to get that out(those sun gear shells are not available except from used transmissions). I got a NOS AOD/AODE planetary, and a ring gear, plus the Sonnax direct drum kit(the version for the AODE(special AODE sun gear)).

So get yours done, pave the way with the J-Mod etc, for the truck 4R VB, and others will follow. Mine will be the same, with a couple of extra new parts in them.

 

[Fredness]

Just trying to "tighten up" the stock 4R70W - We'll run it until it breaks, then upgrade as needed.
This is for towing a 5,000lb trailer with a mostly stock 5.0L (Headers, MF Cats) once transplanted in the Sport Trac.
But I will be sure to look back here when I need to!
I really appreciate all the input.

Last items are in transit:
OD Snap Ring
Superior "Supertuff" K0192 Separator Plate
Sonnax "Zip Kit"
SONNAX Line Pressure Booster Kit 4R70W-LB1

 

[CDW6212R]

The 4R will do fine in the near stock form, if the ATF is kept nice and cool. So do the solenoid, VB stuff etc, and a bigger external cooler, and use great ATF. Avoid high throttle while towing, and OD up any inclines, and it should do great. I towed my 99 wrecked Limited back 170 miles from NC with my 98 Mercury, stock but for new solenoids and accumulators. I had to be very easy coming up one very long(2ish miles) steep hill, 30-40mph for most of that hill. So they can tow the weight, but you have to be thinking about the temperature of the ATF always.

 

[Fredness]

B&M 20,500 GVW SuperCooler, with an external filter, and thermostat in line.

 

[CDW6212R]

That sounds good, what temperature for a thermostat? I wish they made one for 150 degrees, which is built into the 5R and later transmissions.

 

[CDW6212R]

Here's a good spot for a large external filter if you want an FL1A size;

 

[Fredness]

Pulled the VB, was not expecting 3 plates.
Can some ID the mods?
Aftermarket VB gaskets and what appears to be Sonnax check balls and an upgraded OD servo pin (e-clipped).

 

[Fredness]

All 4 OEM Ford servos Ohmed in spec (code was EPC Fail).
No indications of blow outs or leaks.
Have to Ohm the lead frame...
2-3 piston dropped out with VB, piston cover worn from rubbing on the plate.
Is that cover in the 2-3 area designed to keep the separator plate from being worn-thru/weakened?
Reverse servo had a back-cut (slanted end) snap ring.
OD was factory style.

 

[CDW6212R]

The VB may not be original, and the balls would be the identical size even if they are replaced items. Someone has had the VB off before, but it's hard to tell what may be changed. What should matter the most is any debris, and material you find in the VB or in passages etc. If it isn't fouled with material, it should all be usable and just need cleaning, and whatever your plans are for it.

 

[Fredness]

With the VB looking good, EPC Ohming good, I got to wondering...
If the Lead Frame Ohms good, it could be a bad wire between the PCM and the trans.
That harness passes between the engine and the firewall, during the collision the engine could have moved in the mounts enough to pinch the harness, breaking a wire...
(Or more)

 

[transman304]

If you have a heat gun check the resistance of EPC as you heat it up. Also the area I marked on the picture you posted looks to have a check ball trying to “make it to the other side “ very common on this unit. All check balls .250”.
Brad

 

[Fredness]

Zoomed...
I did notice that one was particularly high in the separator plate hole.

 

[Fredness]

Question:
Accordingto Sonnax, to view the casting number I have to pull the metal plate on the bottom.
Does that require a gasket?

 

[Fredness]

This suggests I've got the right parts, so I feel better.
Would still like to look at the casting number though.

 

[transman304]

You have the correct VB. The check ball is worn and will be stuck, should not protrude through plate. That will usually cause lockup to try to come on in second gear.

 

[CDW6212R]

Ditto, I think you have a good VB to use. If the wiring might have been damaged, it would be smart to check those as much as possible. They don't come out easily, so testing them might be the only decent way.

The check balls rarely wear down, but always check them and replace any that look smaller. You should replace the gaskets every time the VB is out, unless they are not very old. They are expensive gaskets now, they used to be about a dollar, I think I paid $2.50+ for each of the last two spares I got.

Keep watching for any material in the fluid as you drain and take apart the VB. Anything you find is a clue about why there was a code, and how much cleaning is needed etc.