4R70W Transmission Mystery that needs to be solved!! Please help!

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Joel3554

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Hello everyone!!

I am trying my hardest to rehabilitate a 2003 Ford Expedition (for reference, it is an XLT Trim with the 5.4L 2V engine and a 4R70W Transmission) for a family friend.

This vehicle was given to my friend and the previous owner stated that the car drives perfectly as long as you make sure to press the button to turn off overdrive before you start driving every time. They had driven the Expedition in this manner for quite some time with absolutely no other issues aside from not having overdrive. Obviously this decreases highway fuel economy on a vehicle that already gulps down the gasoline and is a potential safety risk if you happen to forget to turn off overdrive.

I’ve spent hours and hours looking for any helpful information, but with no success. I have not come across any similar situations on any forum or youtube video. The vehicle shifts and drives flawlessly through gears 1-3 when overdrive is turned off. However, with overdrive in the “normal” on position, it seems to slip into neutral on both the 1-2 and 2-3 shifts. It will eventually shift if you give it a little more gas but only after a couple seconds at higher revs.

When I first took a look at it, the overdrive light was flashing and had two stored codes: P0712 - TFT circuit low voltage input and a P1783 - Transmission over temperature condition. I hooked my scan tool up and verified a bad sensor reading, as it showed extremely erratic fluid temps and would settle at 302° just a few seconds after a cold start.

I dropped the trans pan and replaced the hard plastic molded wiring harness that the fluid temp sensor is integrated into and buttoned everything back up. I made sure to look at the fluid carefully along with the magnet at the bottom of the pan and there were no signs of metal flakes in the fluid or chunks attached to the magnet. Just the normal build up of friction material directly around the magnet. This attempt did successfully take care of the trouble codes which in turn, turned off the flashing overdrive light, but still had no change in shifting ability in regular drive mode.

I did a little more research and saw that there are several things that can cause erratic, or no shift situations including a broken spring in either the 1-2 or 2-3 accumulators and also a possible broken snap ring on the overdrive servo, that can end up dislodging the overdrive servo from the band completely or having a piece of the broken clip get lodged inside the valve body causing shift issues from third to overdrive. I also read that some of the valve body solenoids can go bad and that the rubber check balls inside the valve body get worn out over time and can also cause problems.

I’m not normally just a parts changer and nothing really matched up with my particular issues since it only acts up if the overdrive is on, but I really was not wanting to drop the pan multiple times and so I just ended up purchasing all the parts mentioned above including a freshly remanufactured valve body with upgraded sonnix shifting components and dug into it again.

As I went through the process of removing and replacing everything, nothing was obviously broken or out of place. I put everything back together, filled it back up with trans fluid and went for a drive.

I’m still having the exact same issues with absolutely no improvement! I need help!! Does anyone have any ideas?

It just makes no sense to me that it will drive so perfectly when overdrive is turned off, but refuses to shift properly in regular drive mode. There are absolutely no DTC codes showing up on the vehicle currently, so I really have no clue where to go from here.

There has to be another faulty sensor somewhere or a wiring harness issue of some kind that is bypassed somehow when overdrive is turned off, or maybe even a miscommunication by the PCM or something, correct?

If there was an actual internal mechanical problem inside the transmission, like worn clutch packs or something, it shouldn’t matter if overdrive is turned off or on. It should just never work properly at all, exhibiting the same symptoms no matter what drive mode you’re currently in, correct?

Thank you for any insights that you might be able to provide!
 

OldMedic

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I had the same problem on my 2004 Exp. Over time, the tranny failed and it had to be rebuilt. Unless you are a transmission specialist, I would encourage you to take your vehicle to one and have them figure out what is going on.
 

Frank Swygert

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Sounds more like the OD snap ring has let loose. I don't blame you for trying the easy stuff first, but that rarely solves a "hard" problem. Since the trans has to com apart to fix the OD issue, it's probably time to have it rebuilt.
 

PDR60

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Sounds more like the OD snap ring has let loose. I don't blame you for trying the easy stuff first, but that rarely solves a "hard" problem. Since the trans has to com apart to fix the OD issue, it's probably time to have it rebuilt.
The 4R70W/E family, which includes the 4R75w/e are known for this issue. It's a simple fix. In fact the ultimate solution is the Sonnax part #76833E. Its a redesigned overdrive apply piston shaft that solves the problem for good. You should probably replace the piston and definitely the snap ring. It seems the problem has existed since the ninety's. My son had the same problem as you're having in his 94 4R70w and this solution fixed it. When I bought the wife her new, as of Feb 22, 05 Expedition it was having the same problem. You might get lucky and find all the pieces of the broken snap ring in the pan and on the magnet. If not you may have to drop the valve body and check each valve for free play and find any pieces of the snap ring lodged in a valves. Nice thing is, the pieces will be pretty obvious and easily remove with a small set of needle nose pliers. Hope this helps. The 4R70 family has been around a long time and used in almost every Ford truck in some power team combinations. Pretty good transmission.
 

Jdeezy06expo

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Hello everyone!!

I am trying my hardest to rehabilitate a 2003 Ford Expedition (for reference, it is an XLT Trim with the 5.4L 2V engine and a 4R70W Transmission) for a family friend.

This vehicle was given to my friend and the previous owner stated that the car drives perfectly as long as you make sure to press the button to turn off overdrive before you start driving every time. They had driven the Expedition in this manner for quite some time with absolutely no other issues aside from not having overdrive. Obviously this decreases highway fuel economy on a vehicle that already gulps down the gasoline and is a potential safety risk if you happen to forget to turn off overdrive.

I’ve spent hours and hours looking for any helpful information, but with no success. I have not come across any similar situations on any forum or youtube video. The vehicle shifts and drives flawlessly through gears 1-3 when overdrive is turned off. However, with overdrive in the “normal” on position, it seems to slip into neutral on both the 1-2 and 2-3 shifts. It will eventually shift if you give it a little more gas but only after a couple seconds at higher revs.

When I first took a look at it, the overdrive light was flashing and had two stored codes: P0712 - TFT circuit low voltage input and a P1783 - Transmission over temperature condition. I hooked my scan tool up and verified a bad sensor reading, as it showed extremely erratic fluid temps and would settle at 302° just a few seconds after a cold start.

I dropped the trans pan and replaced the hard plastic molded wiring harness that the fluid temp sensor is integrated into and buttoned everything back up. I made sure to look at the fluid carefully along with the magnet at the bottom of the pan and there were no signs of metal flakes in the fluid or chunks attached to the magnet. Just the normal build up of friction material directly around the magnet. This attempt did successfully take care of the trouble codes which in turn, turned off the flashing overdrive light, but still had no change in shifting ability in regular drive mode.

I did a little more research and saw that there are several things that can cause erratic, or no shift situations including a broken spring in either the 1-2 or 2-3 accumulators and also a possible broken snap ring on the overdrive servo, that can end up dislodging the overdrive servo from the band completely or having a piece of the broken clip get lodged inside the valve body causing shift issues from third to overdrive. I also read that some of the valve body solenoids can go bad and that the rubber check balls inside the valve body get worn out over time and can also cause problems.

I’m not normally just a parts changer and nothing really matched up with my particular issues since it only acts up if the overdrive is on, but I really was not wanting to drop the pan multiple times and so I just ended up purchasing all the parts mentioned above including a freshly remanufactured valve body with upgraded sonnix shifting components and dug into it again.

As I went through the process of removing and replacing everything, nothing was obviously broken or out of place. I put everything back together, filled it back up with trans fluid and went for a drive.

I’m still having the exact same issues with absolutely no improvement! I need help!! Does anyone have any ideas?

It just makes no sense to me that it will drive so perfectly when overdrive is turned off, but refuses to shift properly in regular drive mode. There are absolutely no DTC codes showing up on the vehicle currently, so I really have no clue where to go from here.

There has to be another faulty sensor somewhere or a wiring harness issue of some kind that is bypassed somehow when overdrive is turned off, or maybe even a miscommunication by the PCM or something, correct?

If there was an actual internal mechanical problem inside the transmission, like worn clutch packs or something, it shouldn’t matter if overdrive is turned off or on. It should just never work properly at all, exhibiting the same symptoms no matter what drive mode you’re currently in, correct?

Thank you for any insights that you might be able to provide!
My 06 expedition neutrals on 2 to 3, never gets 3rd so I can't get to 4th/O.D.. I did find the end of the OD snap ring sitting on top of my valve body but nothing stuck in the valves. It's the stamped Steele direct clutch drum itself, the inside where the intermediate shaft splines fit gets stripped out and causes run out on 2nd to 3rd, tranny has to be rebuild.
 

DirtbagChoppers

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I'm having the somewhat same problem mine want go into overdrive and im tracking down the wiring from the transmission range solenoid to the ECM. You start looking at the wiring harness and wires at the top back of the motor. Ive talked to a few people that's have had there transmission rebuild and still the same issue and later to found out it was the wire harness or ground out wire.
 

skip7216

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I’m having a situation where all the gears engage starting with first, then slips until rpm’s regulate and engages second gear, then third gear slips until rpm’s regulate and engages third, then fourth gear slips until rpm’s regulate and engages fourth, then fifth gear slips until rpm’s regulate and engages fifth and then overdrive seems to shift normal. Also sounds like loose parts in bottom of pan rattle on acceleration in any gear. This all just started happening within the last week or so.
I have a 2007 Ford Expedition XLT 4x4 with 162,000 miles. I can do engines, but I’m no transmission guy? Help???
 

skip7216

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Who do you trust to work on transmission? I’m in extreme South New Jersey and there are no transmission repair shops close by?
 

Bmac1955

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Is there a Jasper deal in your area? They take them down and overhaul them with better quality parts. With a pretty good warranty.
 
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