Mustang transmission swap

[mrrick05]

Currently have a 2002 Explorer XLS 4.0 liter with a 5r55W transmission 2WD. Been suffering with all of the typical problems of this model year. Have 160k miles with the past 40k having the timing chain rattle and now transmission 3/4 gear shift issues. I really like the truck in general and the body is in good shape. I read in other posts that an '05 - '10 Mustang engine 4.0 can be swapped but what about the Mustang transmission? Is it also an easy swap? If it is, will the towing capacity still remain at 3500#'s? If a Mustang transmission won't easily swap does anyone have suggestions on a better transmission that will fit the Mustang block? Need to do this on a budget (low budget).
Thank you in advance.

 

[mrrick05]

I'm guessing no one knows the answer to this or that the answer is so simple that I should not even have asked.

 

[shawn022]

Hey guys first post here.

I'v read up on the mustang 4.0 swap and am going to do it to a 2003 Explorer xlt 2wd. So I have the same question as the OP. Will the auto transmission from the mustang swap into the explorer? Thanks

 

[Ljhowell88]

So this may help i have an 02 explorer with a m90 blower on it its also 4wd and has over 210k on the v6 so a lil bit ago i had a total failure while far away from home trans went and blew my x-fer case well for me i dont have a lot of money mainly cuz of beer but still...so i bought a v6 mustang 5r55s trans for $200 had my drive shaft extended did the brown wire mod and was doing burnouts in no time...this is a temp fix but worked for me

 

[Ljhowell88]

Oh yea sry the tailhousings are diffrent from the mustang vs the 2wd explorer trans...the explorer trans tail shaft is longer because im pretty sure the 4wd and 2wd explorer use the same drive shaft so u will have to get the driveshaft lengthened but as for bolt to the motor it bolts right up

 

[mrrick05]

In swapping out the transmission with a Mustang transmission will any codes be generated causing the Check Engine light to come on? I live in a state that requires annual emissions testing and if any codes are read you instantly fail and can't register the vehicle.

 

[Ljhowell88]

Im pretty sure you will have to have the tcm recalibrated for the 5r55s...that was done at the time of the install cuz i have access to the scan tool to do that i also have a sct live wire programer....i do have a parts explorer ill pull the tcm out of to see what it actually does and i can give you a 100% answer on it by this weekend because it seems not one person in the world has that answer....i find it hard to beleive nobody has replaced a 5r55w trans with a 5r55s....the gear ratio's arnt that much different and all the electronis are the same as how many ohm's and voltage they put out

 

[mrrick05]

That would be really appreciated. Thank you for taking the time out of your busy schedule to help out.

 

[Ljhowell88]

Ok so heres the deal....i got home and plugged up a stock pcm out of a 2002 4x4 v6 explorer that is equiped with a 5r55w we programmed the pats system to my keys and started my explorer that was 4x4 but i took out the 5r55w trans and transfercase cuz there both messed up and replaced it with a 5r55s out of a 2005 mustang...started it and took off up the road...i tried everything to get it to throw a code and nothing the only thing i got was my 4x4 high light blinked every now and then...so there it is first hand and actually
done by someone lol.....i had to...
1) get a custom drive shaft made 61" long
2) use the torque converter off a 2002 v6 explorer (the mustang bolts where diffrent)
3) cut the wrap on the harness so i could move the wires then recovered
4) made a custom plate so the rear trans mount would bolt up cuz it was moved up about one inch

 

[zerodevil]

from my transmission shop. your 5r55w cannot be replaced by a 5r55s (mustang). Custom tuning would be required, check with a tuning shop.

 

[Ljhowell88]

Well yea i would by all means have a custome tune put on it to get the best performance out of it...but as for swapping in the transmission and throwing codes no it didnt happen the truck ran good...u also gotta remember the trans shop will also tell u to pull the trans out for a rebuild when ur solinoid pack goes just my .02...the only diffrence in the w/s is the gear ratio...i also saw that TCi's awsome 5r55s transmission for the mustangs have gear ratio's close to the 5r55w and with that u get the sct tuner...ill be running this set up for the next couple days without a tune and ill check my pcm to be a 100% its for a 5r55w.....

 

[zerodevil]

avoid TCI like they are cursed... because they are. I had to send back two $1,000 converters before they got it right. You will likely cause damage to the 5r55s running it on a 5r55w. They are different in more ways than gear ratios. Good luck in any event! Keep us posted.

 

[Ljhowell88]

Well i get what ur saying cuz it makes perfect sense hence why im running a 2004 pcm with an sct live wire as my dd set up but i put the stock 2002 pcm back in because to be honest i really want to know and it seems theres 20 million opinions but nobody honestly knows so i figured hey i have the swap already now no im literally going to do everything possible to get this think to hickup...cuz at the end of the day the swap only costed me $200 for the trans, $150 for the driveshaft and $150 for the pcm (but for testing purposes i wont be using it)...i have to goto upstate new york this week its a total of 600 miles thats there and back so that should be a good test cuz right now im only driving it around town and doing burnouts and stuff like that

 

[mrrick05]

Zerodevil, can you please explain to me why the 5R55 would be damaged? I would have only thought codes may be thrown since only 2nd gear ratio is different. Wouldn't the pcm learn? You will have to excuse my ignorance since I'm not a certified mechanic and only an occasional backyard mechanic.

 

[zerodevil]

5th is different as well. The difficulty lies in how the transmissions shift, i believe the 5r55s can skip gears to get to a desired gear (from OD in 5th to 3rd for example), where as the 5r55w changes through each gear to get to its desired gear (from od in 5th to 5th, to 4th, to 3rd). Because of this difference there is likely mechanical changes between the two transmissions. Now if the 5r55s is harmed by trying to dowshift through so many gears on a 5r55w tune you have an issue. Talk to henson and see what he thinks. To be honest im only going on what i have read on the internet (yeah, i know haha) and what my transmission shop said when i had the transmission rebuilt this last summer (wanted to go to the 5r55s due to lower ratios). If a $500 tune saves you a $3,000 rebuld later on id say its worth it.

 

[Wills05xlt4x4]

The s is syncronized thus NO gear jumping like the w CAN DO!(part of their issues was jumping around gear wise...ie 1,3,5BOOM!)

 

[shawn022]

I believe that I have the 5r55s in my 03. V for transmission code on the door. So, if thats the case would I have any problems using the mustang 5r55s? Would the tail housing length still be different? Thanks

 

[Ljhowell88]

Im pretty sure there both syncronized trans's the w&s is for wide and short and to be honest its all a tuning issue now this is my personal opinion...and i love to learn...keep in mind im no certified mechanic but my dad is for the police department here and well they love there fords...but we rencently just had both transmissions taken apart side by side and i honestly couldnt find a real diffrence in parts (i do understand just cuz it looks alike dosnt mean it is)...so after that i went and bough 3 2005 mustang v6 5r55s transmissions and a 2004 pcm cuz its an electronic issue...considering tci takes a 5r55s and puts gears similar to the 5r55w..i also run a m90 charger at 8psi and some other goodies and in no way shape or form do i baby it... Now this topic came up and i went and put my 2002 pcm back inwith no tune at all to see whats going to happen (yes i lowered my boost on the blower) and a have about 1200 miles on is so far with no codes or issues...im not saying im right i just want to kno cuz no body seems to kno we all have our opinions but i kinda think im the only who has came out and actually done it and is running it...i drive it to work everyday a total of 120 miles..yes i parked my brand new diesel for this plus its cheaper and i dont care if the trans blows to pieces i have 2 more and i have a pcm and a sct tuner...but i honestly think if this swap is done deffintaly put a tune on it no if an's or buts about it

 

[Ljhowell88]

@shawn.. Yes the tail housing are diffrent the mustang one is alot shorter...when i put the mustang trans in my 02 v6 4x4 explorer i had to get my drive shaft lengthend to 61" i think it was 10 or 11 in total...and made a plate for the tranny mount

 

[Wills05xlt4x4]

I tried to have level ten or performance automatics build my trans since they do mustangs, they said due to differences it wouldn't work just swapping one in(direct replacement 4x4) and would need a core(mine had been redone 3x and I'm still convinced the core was the issue in my case) started with a jasper and built it up, deep pan+dipstick(for a mustang gt), external filter, hp cooler, and too many internal changes to list...
when mine was built that was what my trans guy told me about the w vs s(buddy's 02w DOES jump gears my 05s does NOT)
That said a s computer should function a w almost like a s but a w computer may make the s jump gears like its not made to do thus potentially causing damage... (why they say it won't work)
Nobody really knows without trying(im not) but that'd be my assumption as to it all...
not to hijack but how's that m90 working out?rpcaster kit? W/m? Stock internals?hp gains?