Need some help. I got this code and symptoms of 1-2 hard shift and no torque converter lockup. No flashing overdrive light on shifter. If I switch off engine all shifts are smooth until I pass 45mph. I would feel the TCC lockup. This doesnt happen the as i come to a stop I get a harsh 2-1 shift. Key off restart then shifts smoothly up and down provided I dont exceed the TCC lockup speed. This leads me to the TCC solenoid I think. Fluid has been changed regularly. Had to drive 300 miles to get home. Only for the plate trans cooler the fluid would have overheated as on inclines on cruise control the engine would rev to 3k to keep the speed at 70mph and I could see the fluid temp increasing. Fuel consumption was very bad almost a full tank (with no ac). Doing some research there is talk about valve gasket blowout Epc solenoids etc, though these were for Rangers and Explorers, no real mention of Aerostar. Thanks.

 

you must have a 96 or 97 with the 4R44 or 5R55 serieds tranny? same tranny used across the vehicles you mentioned so problems exactly the same.

indicates the TC slippage is exceeding the PCM prog'd set parameters.
steps to repair listed by most cost effective first

change the TCC solenoid, they wear out because of high demand PCM caused usage.
while you have the pan off, change the VB gasket and the ATF filter

do complete 12 qt. change ATF. use only a Mercon V rated full synthetic.
Mobil 1, Amsoil or Redline. expensive but far less than a tranny rebuild. especially cuts down on valve body solenoid wear, the PWM EPC sol. valve is $300. replace religiously every 30k. one can't disregard ATF changes in these like an old TH400 GMC.
ATF breakdown and failure is the major cause of this series of tranny failures
fully flush lines, coolers and TC,
see forum sticky

if you still have a problem
then the TCC sol. hole is worn, rebuilt valve body time.

reason there are hard shifts is the PCM sensing a tranny failure and responds by commanding the PWM EPC solenoid valve to increase line and tranny pressure which results in harsh shifts.

if it were mine and i planned on keeping it, i would have a professional transmission shop do a complete rebuild with valve body, all solenoids replaced, new torque converter, new clutch packs, new bands, new servos
get references first.

 

So it is an electronic OD transmission? So far mines been faultless.
How many miles on the transmission?

 

Sounds like your trans has been cooked. You should take it out of OD manually when you hit those inclines. The torque converter does not like to come unlocked for long, and those inclines can cause the TC to unlock without dropping down a gear. The fluid recirculates inside the TC as it does its torque multiplication thing and can get hot enough to turn the TC purple. The only reason it doesn't catch fire is because there is no air in there.

 

Update. Thanks to the previous posters for all the help and input.The trans has 300k on it. Ive had a plate type oil cooler on it forever and used coastal semi synthetic fluid throughout its life. I ordered and installed a complete set of Bosch transmisssion solenoids. I got the set for $180 from Electricaladvantage.net. Installed them and so far it is shifting beautiful. Buy buying the complete set the average unit price is cheaper. One thing of concern though is that the fresh oil previously installed about 1000 miles before the new solenoids was a blackish color not burnt. This may be from the Torque converter. The solenoid replacement was easy enough to do.

 

any burnt acid odor to ATF
should be almost odorless, just a slight oil odor

with no TC lockup, ATF temps will easily climb above 250d F even with the best cooler avail.
probably should do a drain and gentle 12 qt flush in 1000 miles, there will be varish in the tranny from the hot ATF.
will take several changes for the ATF detergents and cleaners to remove.'

varnish (aka broken down lube products) may cause clutch and band slippage until clean

 

solenoids after replacement were not a success. Got and installed a rebuilt valve body,( thinking worn valve body bores) still the same isssue,. This leaves the torque converter and pump seal (7L323)as the only other potential problems. The tcc engages when cold but then as it warms up it throws the P1744 code only. I got a converter from advance autoparts and will get the seal at Ford. The trans shifts smooth with the new valve body, no delay going to reverse or drive.

 

I got a torque converter from advance autoparts

 

Thanks to all for the help with this issue. When I replaced the torque converter from Advance I also replaced the seal (dealer item)that sits at the end of the outer shaft that slides into the torque converter. It was a scarf cut seal. The replacement seal 3L2Z-7L323AA was a one piece gray seal and was a teflon type material. The black appearance but not burnt smell that came from the fluid before I changed the converter may have been the clutch slipping maybe due to fluid pressure leaking through the $4 seal. This seal may be an issue with some converter related codes. As mentioned before I replaced the valve block with a rebuilt unit which has all the upgrades. This resulted in quick reverse and forward engagements and faster upshift times.

I could not believe the sludge build up coming from the converter when I drained it for core return.

 

Congratulations on this involved repair.

Just wondering, do you know if the van was put to hard labor to get the transmission and torque converter into this state?

I also wonder about torque converters for the Aerostar; are there different choices for stall speed that work better with the bigger or smaller engines?

 

The torque converters from Advance for my 4.0 97 Aerostar with the 5r55E is listed as an A4ld model from their computer. It appears to be the same part number as the explorer going forward and back a few years on their data base, so I am not sure there are different stall speeds. I got the van in 99 with 30k and am the only driver up to 300k. I will see how far I can get on this transmission before a rebuild. The large flat plate cooler I installed when I got the van is in my opinion the reason it has lasted as long as it has. I tow with it and never lock out the overdrive.

 

You should order those kinds of parts from a specialist transmission parts distributor. They can better answer your questions, and they tend to carry higher quality parts. I had mine installed by a local shop, but there are "heavy duty" torque converters that are stronger internally than a regular one. However, what happens if you don't lock out OD is that the trans will seem to downshift to a gear between 3rd and 4th, but in reality it is unlocking the torque converter to increase torque multiplication (more torque at the output than the engine is putting in). The result is that the fluid inside the torque converter recirculates as it is exposed to severe shear stress. The fluid can reach temperatures as high as 700 degrees, and the cooler does not help because this heat is trapped inside the converter. The cooler can keep this hot fluid from damaging the rest of the trans.

 

I think that by locking out the od switch you bring the coast clutch into play. This will cause even more heat as as you come off the gas and on. engine braking is being used where the trans is driving the engine, I have never used that switch for the above reason and am now at 303k. As regards the converter and the lock up duty cycles it goes thru a lot of lock and unlock in day to day driving.

 

I really appreciate this thread. On my '97 AWD I had the same P1744 show up last week, and due primarily to this thread I have fixed it the same way: new torque converter & 7L323 seal.

I will not say this was an easy fix. I have had four A4LDs in and out of my various Aerostars, but this was my first AWD version and maybe it's just me getting older, but it was a lot less fun than I recall any of my other Aero trans R&Rs.

I run AMSOil ATF. With dry converter, pan, and coolers, I used ~11 quarts to refill.

A tip: I got the code one afternoon and researched it immediately. The fluid was just a little purple. I drove another 200 miles whilst I gathered the converter, seals, etc. and by that time the fluid was very dark and the converter was not unlocking at stops anymore. I had it towed to the self-serve garage I rented ($35/hour or $300/day with a lift) using my AAA RV coverage, rather than take a chance driving it any further.

When I flushed the coolers (three cans of LubeGuard 19001 aerosol cooler flush), it was incredibly contaminated.

I had installed a rebuilt valve body only nine months previously, so the fluid should have been "like new". It went from a bit dark to nearly undriveable in about 200 miles.

If you get this code and aren't planning on a rebuild, don't drive it.

[In ~2007 I had this same failure on a 85k-on-HD-rebuild A4LD from Portland's Transmission Xchange in my '89 Aero, but the '89 won't set a CEL for the condition, so I drove it until it stopped moving: plugged filter = no hydraulic pressure = neutral. I replaced the same parts on that one with similar results, but some mechanical part failed 12k miles later. I put a used '90 trans in it after that and sold it -- with 330k miles on the engine & chassis.]

Here are a few pics of that input shaft seal. It was $5 at the dealer

 

Great that you got to fix it promptly. Since my repair mileage at 300k I'm now at 465k. Fluid and filter changes every 50k with max life by valvoline from Walmart. Shifts well with no issues. So with the converter and valve lock changed its still on original clutches, brake bands, servos etc.