5r55w and 5r55s Solenoids.. Are they the same? | Ford Explorer Forums - Serious Explorations

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5r55w and 5r55s Solenoids.. Are they the same?


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September 28, 2007
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I have been lurking around here for a while now (first post) and have been impressed with the community. I especially like the diaries and step by step tutorials which give people the confidence to tackle their own repairs and modifications.

I have been combing the forums to help troubleshoot my trany issue in a 02 explorer (91,000 miles) with v6 and 5r55w. Similar to many others, but I have found a singular cause (There may not be one). High rpm in first but always shifts to second, sometimes it shift fine. Overdrive kicks in and out with every hill in the road. It eventually throws a P0775 Pressure Control Solenoid "B" code and the overdrive light flashes no other codes yet. I know that may indicate a bad solenoid, or other problems. I am thinking overdrive servo or maybe valve body, any insight on this will be greatly appreciated.

Anyway I thought changing out the solenoid would be a good place to start and I would have a chance to look over the fluid and filter at the same time. I can get the a Ford part # 4L2Z-7G391-AA which I think is for a 5r55s much cheaper than the one listed for the 5r55w. The look identical and I have found both statements to support and refute their similarity. Anyone know for sure? The 5r55s Solenoid is cheap enough to just replace and just see what happens. the 5r55W is three time more. Most of the issues I have seen similar to mine are not the Solenoid and I am hesitant to drop $300 to replace it since I do not think that it is. On the other hand, I could consider this preventive maintainance since these things do fail about this mileage. Again I welcome opinions, as to cause of this common problem.

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The 5R55W uses a unitary solenoid block, not individual solenoids. Unfortunately you cannot replace individual solenoids in the W, you have to replace the block that contains them all. THAT is why it is so expensive.

thanks for the fast reply,
I think that the 5r55s is also the block type as they apear at least on the surface identical. There are for some reason some cheap solenoids for the 5r55s floating around at the moment for less than 80 bucks a copy. Anyone know if there is some difference in the winding impediance?

The W S and N are all close kin and more or less superficially identical. All use a solenoid block, as does the 4R100.

There was soem change in the 4R44. 4R55 and 5R55 solenoids during the time from their introduction to present in that they were redesigned to provide an impedance signature to the computer, but as far as I know the impedances proper have not changed, and range of impedance for shift solenoids (and EPC and TCC) has remained the same.

Kind of relative here. I have an 03, however according to an Oasis report my truck has the 5R55S. I think I need to replace the Solenoid block to fix a PO755 code I have.

I found this Solenoid block for $85(scroll to bottom) http://bulk-surplus.com/bulk.aspx

It says '04 and up, does this mean even though I have the 55S since mine is an 03 I need to find a different solenoid block, or were the Explorers done like the 01 Mustangs where early production versions recived the old T-45 tranny and late production models recieved the 3650.???

My tranny seems to be doing the same as above. RPM's go up to the 4k range before shifting from 1-2 and 2-3, no slipping, no harsh shifts. Local tranny shop said gear ratios were off and they want to pull it to further diagnose the problem. I would be willing to take a $150 dollar shot at fixing it. I just can't see spending $450 for the solenoids and the time if I have to get the other solenoids.

stalls when put in drive

ok guys im new to this but not new to working on trucks
i need some help if you could
i got a 00 explorer 4.0 4x4 with 120,000 miles i recently bought.

my problem is when put in drive it will stall out violently but when put in reverse it will work, i got this truck to move in 4 low a few times after slamming it in drive with some rpms.

ok i got some codes off my truck
po708 trans. range sensor input high
po743 torque convertor circut malfuntion
po755 shift solenoid b, c , d malfunction

i need to know if this is a group of sensors and where is it located please help!

can we get back on subject? Can we use the 5r55s s-blocks in our 5r55w transmissions? I too am suspecting that thing in my truck but i'd love to be able to spend 80 instead of 300...

Mine too should have a 5r55w but the door tag says Transmission code (TR) V so that means a 5r55s. maybe because the truck is a late build date 2003??

Anyways, anyone know about solenoid pack differences and overall trans differences?? Or was the 5r55s introduced with minor mods allowing Ford to install throttle by wire and stuff??