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4R70W Transmission Rebuild Diary

Discussion in 'Explorer & Ranger Transmissions, Transfer Cases, &' started by Glacier991, February 23, 2005.

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    1. Glacier991

      Glacier991 EF Tranny Guru Moderator Emeritus

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      Foreward to this Diary:

      I have only been building transmissions now for about 4 years or so. I do not claim to be a pro, expert or genius about this topic. Yet, I have been wrenching for 30 years now and at one time did work for FORD. (Seems like another life). I have built engines, component parts, done A/C, Ignitions, suspensions, etc ...and even have a piece of my metalworking handiwork sitting on another planet. (Another fun story).

      I started into auto trannies because of a sense of curiosity.... and what I found on the internet insofar as help for those needing it was concerned made me slightly angry. Those who build transmissions seem to LOVE to impose an air of mystery and mystique about them and try to make folks think only "the chosen few" can actually rebuild them. BULLSH*T. I have even seen folks "pretending" to be helpful pull back their help when it was most sorely needed under the guile of, "Oh well, a valiant try, poor dumb amateur, but now you need to come to ME!"

      I know a lot about how automatic transmissions work and how to build them. Yet, I possess no "trade secrets" or "proprietary information" as some foolishly claim to possess. If I discover/learn something along the way.. I will share it - and I am constantly learning. My goal is to see those of you who try ...succeed, not fail and serve as a warning to others (as I see elsewhere.) To assist you, I not only share my knowledge freely, I also loan tools when those are needed. I will steer you to the best buys for parts and help you avoid the scams...I believe that for the ones who have some good automotive skills and want to try - You CAN do it.

      Sure, rebuilding an auto transmission is not for someone who can barely change their oil... and in fact probably not for 90% of shade tree mechanics....but I see folks capable of awesome things afraid of auto trannies when they could easily do them. I even see people on other sites who are in the business of AT rebuilding, either as a main profession or a sideline trying to scare folks off from trying to build their own.... feathering their own nests - the same folks who claim to have "trade secrets". GIVE ME A BREAK fer chrissakes. For example - clutch clearance is not a "secret" - "ohh I use .037, instead of .028 to .045." Kill me if you have to tell me.

      Also...the amount of material to remove from a clutch piston so you can add extra plates to that clutch and still make it all work, is MATH, not "proprietary information". GET a CLUE guys!

      So, I decided to do the Diary series. So far dozens have successfully rebuilt their own automatic transmissions using the Diaries and other reference works, but were inspired here. If you are an advanced amateur, and can pay attention to detail (AT's are all about detail), you can do it.... no matter what "THEY" say. I am here to help. I am not in the automotive trades, nor do you need to be.

      I hope my Diary can give you a bird's eye view of the process, and even if you do not decide to "do it yourself", you will have a much better sense of what an automatic transmission is all about. Enjoy.

      Glacier



      BACK TO WHERE THIS THREAD STARTED:
      ("Once Upon a Time Long Ago.....")


      Alright, there IS a slight tease built in here in that I am a few weeks away from really getting into this. I have slowly been acquiring parts - new pump, new mechanical diode, shells and drums, steels and rebuild kits, brand new valve body, kevlar bands, spiral retainers, new torringtons, new updated accumulator pistons, etc.... so once I get going it will happen pretty fast...

      I am starting this thread now for a couple reasons. First, If anyone has ideas they want to throw in, or things they want to know about or see in this rebuild, now is the time to speak up. Secondly, and sadly, I have no use for this trannie once it is built, so if someone wants to have a "build to suit" hi-perf 4R70W this can be your trannie, and I can build it to your specs....

      Either way I will try and duplicate or add to what I did with the 4.0 Liter A4LD trannie, only this time with a much more hi perf trannie capable of some significant mods (oh and for the 5.0 V-8 engine). Stay tuned.

      ps. those of you that have experience with mod's to this trannie please share with me.

      pps. Oh, and...I did previous Diaries sometimes in what was more or less stream of consciousness. Years later when i need to refer someone to something specific, it is a pain. This Diary I am setting up differently. There may in the end be 20 or so separate threads making it up, but it WILL be easier in the future to go to your own particular area of interest. So, on that note...this may be a good place to post and update links to the other threads in this Diary. I'll try and post links at the end of each thread to the next, but maybe ONE place for the whole set would be a good idea... so here goes (this thread will be updated constantly until I have them all in when I finish)

      Part 2 -Output Shaft, Ring Gear and Hub (and a discussion of extension housings as well)
      http://www.explorerforum.com/forums/showthread.php?t=157283

      Part 3 - Torrington bearings and Thrust Washers (including selectives)
      http://www.explorerforum.com/forums/showthread.php?t=157376

      Part 4 - Servos and Accumulators
      http://www.explorerforum.com/forums/showthread.php?t=157428

      Part 5 - Direct Drum and Hub
      http://www.explorerforum.com/forums/showthread.php?t=157440

      Part 6 - Bands (2 of em)
      http://www.explorerforum.com/forums/showthread.php?t=157481

      Part 7 - Main Planetary and Sun gear
      http://www.explorerforum.com/forums/showthread.php?t=157487

      Part 8 - Case Support
      http://www.explorerforum.com/forums/showthread.php?t=158559

      Part 9 - Reverse Shell and Sun Gear
      http://www.explorerforum.com/forums/showthread.php?t=158566

      Part 10 - Forward Clutch
      http://www.explorerforum.com/forums/showthread.php?t=158888

      Part 11 - Reverse clutch
      http://www.explorerforum.com/forums/showthread.php?t=159597

      Part 12 - Transmission assembly up to the Intermediate clutch
      http://www.explorerforum.com/forums/showthread.php?t=160569

      Part 13 - Intermediate Clutch
      http://www.explorerforum.com/forums/showthread.php?t=159423

      Part 14 - End Case (pump) Clearance - Selecting the Right Selective
      http://www.explorerforum.com/forums/showthread.php?t=160708

      Part 15 - Pump Modification & installation
      http://www.explorerforum.com/forums/showthread.php?p=1462794#post1462794

      Part 16 - Output Shaft Speed Sensor installation
      http://www.explorerforum.com/forums/showthread.php?t=161096

      Part 17 - Parking Pawl Installation (coming soon)

      Part 18- EPC solenoid installation (coming soon)

      Part 19 - Shift lever and seal installation (coming soon)

      Part 20 Digital transmission range sensor installation (coming soon)

      Part 21 - Valve Body - Part 1 - upgrades (In progress)
      http://www.explorerforum.com/forums/showthread.php?t=186732

      Part 22 - Valve Body- Part 2 - Separator plate and installation (coming soon)

      Part 23 - Pan install and button up of transmission. End of Project (in my dreams)

      Part 24 - Parts listing with part numbers, cost, and where to buy (coming soon)

      Part XX - A Discussion about Friction Material (not sure where it will finally go so for now it is the only double X rated thread on the site!) :eek:
      http://www.explorerforum.com/forums/showthread.php?t=158669

      General Q & A on this Diary: http://www.explorerforum.com/forums//showthread.php?t=161450

      Changes to the 4R70W in 2004: http://www.explorerforum.com/forums/showthread.php?t=188119
       
      Last edited: June 2, 2007
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    3. V8BoatBuilder

      V8BoatBuilder Transplanted Bostonian

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      Subscribing for updates.
       
    4. CDW6212R

      CDW6212R Elite Explorer

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      I think that the magic in building an AOD, through the 4R70W, is to get the latest model core to start with. Ford constantly improves lubrication, valve body calibrations, and the solenoids.

      In AOD's, the reverse band usually will last the lifetime of the transmission, including all rebuilds. The factory part is cast iron as I recall. A kevlar piece might gain some lifespan for the drum though. There are different pins that can be installed to tighten up the bands.

      If you can get Kolene steels and blue frictions at a reasonable price, try them.

      I don't know if there is something better, but the last I heard, the MarkVIII direct drum had the most clutches. Various companies sell thinner direct clutches.
      There is debate about whether eight or nine thin clutches is actually more reliable than six or seven normal thickness clutches.

      Do remember for performance use, to get the three OD "A" servo parts from a Supercoupe. There is also an aftermarket(even larger) OD piston, etc.
      Regards,
      DonW
       
    5. Glacier991

      Glacier991 EF Tranny Guru Moderator Emeritus

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      Don, thanks. I was going to see about Alto clutch pack upgrades and kolene steels. Is there a way from the casting number to decipher the place (read vehicle) the valve body was ideally manufactuiurered for ? I plan to mod the VB, but would be curious. Did this transmission (in all of it's variations) go through the stamped steel to cast iron thing with the forward drum or OD? Appreciate your info!
       
      Last edited: March 23, 2007
    6. boominXplorer

      boominXplorer Elite Ranger Elite Explorer

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      as far as i have gone into the 4r70 is though the valve body to install my baumann. Now I am having tranny toubles again. Is this one going to be 2wd?
       
    7. Glacier991

      Glacier991 EF Tranny Guru Moderator Emeritus

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      well the core is a 96 2WD. I'll need to see what I'd need to do to make it 4WD or even if all that is possible. I know the A4LD like the back of my hand..the 4R70W I am still reqading up on, so any advice, thoughts or info may help me jumpstart it. If the 2WD/4WD/AWD aspect is outputshaft/tailhousing related (as I assume), I'd let a potential buyer decide what he/she wants.
       
      Last edited: April 23, 2006
    8. tmsoko

      tmsoko Active Member

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    9. Glacier991

      Glacier991 EF Tranny Guru Moderator Emeritus

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      thanks, a terrific link. Here is another. With those 2 and some common sense this should be a fun project. There will be some decisions to make along the way, and I'll tell you I am not necessarily of the school that more plates and thinner steels are the best thing since sliced bread and don't come at a big price in heat production/lack of dissipation.... anyway here is the other link I mentioned:

      http://www.mn12performance.com/mn12-techinfo/trans-tech/4r70w_rebuild.html

      I'm hoping to take these great links and tie a photo piece into them for a step by step.

      (btw... those links together are pretty incredible: ain't the net a great place?)
       
      Last edited: June 2, 2006
    10. CDW6212R

      CDW6212R Elite Explorer

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      I'll read those myself soon. Thanks Todd for any information, I want to learn anything that I can.

      If you haven't yet discovered this, I believe ideally you'd like to use the valvebody that comes with a transmission, so the calibration matches everyting for that model and year.

      2WD/4WD is just a matter of changing the output shaft, and tailhousing.

      I'll be building a 97 AWD model soon myself. LOL
       
      Last edited by a moderator: March 23, 2007
    11. Glacier991

      Glacier991 EF Tranny Guru Moderator Emeritus

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      Good Don, maybe we can collaborate.
       
    12. Glacier991

      Glacier991 EF Tranny Guru Moderator Emeritus

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      Ok, I'm feeling guilty. I started this now and haven't posted any pictures. Last time in the A4LD Diary OperaHouse complained that there were no naked trannie pics in 2 full pages of posts. So I cannot post any trannie pics, yet, but let's explore a NEW valve body.

      I bought this on E-Bay, brand spanking new....pretty in pink... this is the top (or installed, bottom)

      [​IMG]

      flipped - the separator plate... virgin...

      [​IMG]

      Of those round things? Reinforcement plates.... hmmm wonder why the gaskets blow out on the 5R's? Possible mod ideas Brain?

      Ok, so how new is it? Is this a clue?

      [​IMG]

      Here is what I know as the manual valve (on the A4LD/4R/5R)

      [​IMG]

      The 4R70W has 2 shift solenoids, they are paired in a single unit... I'll resist calling it a "pack".... looks like this...

      [​IMG]

      the TCC solenoid is seemingly "tiny".. it sits nearby

      [​IMG]

      So where is the EPC? It fits in the case! and NOT the VB. I'll show you some pictures of it and the harness next.... (Operahouse, you ok now? <g>)

      I have a harness and all the solenoids, plus the temp sensor... been click testing it on the tester... trying to compare it to new.... but I do not have a NEW EPC solenoid... and FORD did make a change. Need to find out if mine is pre or post change. It click tests pretty good... the TCC is the weakest.... more pics of thos to come. And soon the valve body Mods (ON A NEW VB!)
       
    13. Glacier991

      Glacier991 EF Tranny Guru Moderator Emeritus

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      Well guess what... sharp eyes may have noticed the suffix AB on the above parts. My old ones are all AA... First generation...some would not even fit (the "pack, for example") on this latest VB.... here we go (OperaHouse, you watching? <g - I love to tease/taunt my friends who have teased me>) First up.... the shift solenoid pair.. old above the new on their valve body.... notice the AA on the uppermost solenoids... and also notice their tabs would NOT fit the VB....

      [​IMG]

      Here is the AB designation and full part number on the new....

      [​IMG]

      But wait, you can't just go out and buy a new one and replace it, why ? The connector is different (so it is all OLD style, or all new short style on tye harness... you will replace all with new or none, in other words.... let me show you... AND in the process, show you good engineering vs less good. Before I start this, I'll remind you that solenoids are activated by grounding a circuit, not by powering it. On the old "pack" connector, you could see common power (+) and then each solenoid 1 or 2... like thus

      [​IMG]

      on the new style "pack" connector:

      [​IMG]

      (better pic coming)

      The old style connectors were more encosed.. or had longer connector flanges may be a better way to say it... here is the TCC.. old

      [​IMG]

      versus new:

      [​IMG]

      Side by side

      [​IMG]

      Once again AA versus AB

      I do not have an "AB" EPC (yet) but here is the original one...an "AA"

      [​IMG]

      and the snout end...screens and 0- rings

      [​IMG]

      more to come, stay tuned....long road ahead.
       
    14. V8BoatBuilder

      V8BoatBuilder Transplanted Bostonian

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      Chris... Post 1999 the 4R70W wiring harness was a printed circuit board, pre 1999 it was still a wiring harness with plugs and wires.

      Nice find on the valvebody... that was made on my birthday!
       
    15. Eneurb

      Eneurb Active Member

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      They actually call the wiring a "lead frame".
       
    16. Glacier991

      Glacier991 EF Tranny Guru Moderator Emeritus

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      Ok.... in Feb I said a couple weeks. It is August. I'm getting close now.... I am doing my homework on the 4R70W..... should have a donor soon, but picked up a case to inspect.... want to share that with you... here it is valve body side up

      [​IMG]

      Quite interesting in comparison to the A4LD and 5R55 series. The servos are all inside the valve body.... no heat shield issues. So let's go around and see what we got...

      Let's start with the 2-3 accumulator... small, the big one above is the low/reverse

      [​IMG]

      moving forward the low reverse servo... BIG

      [​IMG]

      and forward of that the OD servo... surprisingly small..

      [​IMG]

      and to it's right, the 1-2 accumulator

      [​IMG]

      lastly.. IN THE CASE, we have the EPC solenoid....and it is an AB model!

      [​IMG]

      Notice the SIZE of the fluid passages! AT the rear we have the parking pawl stuff... there is a steel rod that fell out, I have it, but for pics I replaced it with a skewer...

      [​IMG]

      and lastly, since this is a one piece case... to get to the TC drain plug (yeah these have one) there is a rubber plug on the bellhousing portion

      [​IMG]
       
      Last edited: August 27, 2005
    17. Glacier991

      Glacier991 EF Tranny Guru Moderator Emeritus

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      Now inside. Amazing how small the geartrain cavities in automatic transmissions are, and how similar... let's peek into the 4R70W's

      [​IMG]

      Two things struck me... the size of the band anchors, and the thin-ness of the back case web...

      [​IMG]

      That thing sticking up on the left is the tip of the low reverse servo.

      Cases came in 2 flavors, a 2 bolt starter (the A) case and the 3 bolt (the B case)
      This is an A, used in Explorers

      [​IMG]

      Here is a better view of the anchors...the paired set is the low/reverse (look very much like the A4LD/5R55), the single honkin one is the OD

      [​IMG]


      Ok time for some help. I have the manual that purports to explain this case tag... but I cannot decipher it, anyone help? I know that the PK numeric in the upper left is the model number, and two lines below that is the serial number (this is repeated in the bar code underneath and below it) but the 8H?. My info says "for example" a .6 sideways meant the transmission was for a 4.6 litre engine. The upright 8H means? V-8? 4WD ? and the F87P-7000? I'm curious...I know from the fact there was an AB version of the EPC solenoid in the case this is newer than older....probably 98

      [​IMG]

      Now the taps? I think there are 4 pressure taps... I hope I am right... here they are... 3 up front

      [​IMG]

      and one in back

      [​IMG]

      lastly the rear.... notice the marks in the rear bore, I will investigate that

      [​IMG]

      When you see this case again it will have been degreased, pressure washed, bores scrubbed, fluid lines blown clean, bolt holes tapped and cleaned and the case sandblasted and painted.

      Ok...Next up... clutch sets, planetaries, one way clutches and "mechanical diodes" and of course, bands etc. GUTS. Stay tuned. be patient with me.
       
      Last edited: August 29, 2005
    18. V8BoatBuilder

      V8BoatBuilder Transplanted Bostonian

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      Sweet! Been waiting for this info.

      Thanks Chris!
       
    19. 410Fortune

      410Fortune ELITE BRONCO2ERER Moderator Emeritus

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      These ones have to be rebuilt too? Say it aint so!

      hahahaha hopefully only once and hopefulyl only every 150+ K miles....

      Geesh.

      U = the man, I know all these tranny tech guys love your rebuild diary's, I just look at them with my jaw on the floor, valve body is about as deep as I go, still. hahaha
       
    20. V8BoatBuilder

      V8BoatBuilder Transplanted Bostonian

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      Let's hope not! I'm at 130k miles, and still going stuper strong. Knock wood. The Baumann kit was a terrific addition to the trans.

      But, knowing how to do a rebuild when the time comes is fantastic.
       
    21. 410Fortune

      410Fortune ELITE BRONCO2ERER Moderator Emeritus

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      of course. I have a 96 4r70W with 180K miles, it still drives good, although it does hesitate a bit from N to D, but it still doesnt miss a beat on the road!
       
    22. Glacier991

      Glacier991 EF Tranny Guru Moderator Emeritus

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      I have an A4LD with 214K on it.... working fine (except up long grades on a hot day). phhhtttt. <wink>
       
    23. Glacier991

      Glacier991 EF Tranny Guru Moderator Emeritus

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      A Quick Trip Thru The Guts Of The 4r70w

      I have a pretty complete gear train I have acquired piecemeal... (still working on accomodating Section525 to pick up that donor.. he has been WAY patient with me.)

      As I put the stack together the one thing that struck me was how big and heavy everything was. Clearly a beefier trannie than the A4/4R/5R!

      The top of the stack would be the pump - last thing in, first thing out. I like to always use new FORD pumps in rebuilds, and I have one, here it is:

      [​IMG]

      and back.. the back also serves as the clutch piston for the intermediate cutch, wierd to my mind. More on assembly....

      [​IMG]

      The front clutch has the input shaft which stabs thru the the hole in the pump and into the TC. Here is the asssembled stack

      [​IMG]

      When installed this space is used to build up the intermediate clutch, it's kind of an odd setup, like I said, as you'll see on assembly.

      [​IMG]

      There are some sealing rings that need special care... this is a new drum so these are factory and primo
      [​IMG]


      The top of the stack is the "mechanical diode" an upgrade that is a critical upgrade.

      [​IMG]
      [​IMG]

      I get a kick out of that name. For those not electronically inclined a diode is a device which permits current to flow in only one direction.... a valuable trick. But to name a one way clutch as a "mechanical diode"... who'da thunk it?

      Under this is the reverse clutch drum. I have tried to highlight the "dog ears" that fit into the input shell. This is a critical wear point.

      [​IMG]

      I'll post a few more pictures to illustrate this

      [​IMG]

      can you make out the wear? Here is a dog ear close up... this is not "terrible" wear, but evident.

      [​IMG]

      and here is a look at the input (drive) shell where the dog ear engages

      [​IMG]

      With the reverse drum and clutch off, the forward clutch and input shaft can be removed
      [​IMG]

      Not important per se, but sometimes when people wonder why they might suffer low line pressure, it is because a check ball might be stuck open... here is such a check ball in the forward clutch shell..
      [​IMG]

      Next we come to a stub shaft, the "intermediate input shaft" commonly just known as just the "stub shaft". In super high horsepower apps this can snap in half...(yeah!) and there is an aftermarket super hardened one.... pricey. Probably only necessary if you are running 600 HP.

      [​IMG]

      and here it out

      [​IMG]

      Next up.. or down as the case may be, input (drive) shell and sun gear

      [​IMG]

      Under this is kind of the equivalent of a "center support" in the A4/5R series.. it is the "planetary carrier" under it is a ring that engages a roller sprag in the end of the planetary gear assembly

      [​IMG]

      The backside with the ring for the sprag

      [​IMG]

      Here is looking into the back end of the planetary and the roller clutch (sprag)...

      [​IMG]

      Then we can remove the forward clutch sun gear

      [​IMG]

      Might want to pay special attention to these little splines....

      [​IMG]

      and then the planetary, a HUGE beefy thing. Heavy.
      [​IMG]

      [​IMG]

      this splined end fits into the hub for the direct clutch, making the direct clutch able to hold the planetary carrier stationary (you know what THAT does? right?)

      [​IMG]

      Note the scoring in the bushing. It will get replaced with a new one. (as will everything else used that gets reused)

      Now we are down near the bottom. We have the ring gear and inside it sits the direct clutch... this one is stamped steel. The direct clutch started in the AOD as cast iron, then went stamped steel then in somewhere along the line into the 4rR70W production went back to cast iron... so we know this one is "probably" not 4R70W..... but for illustration purposes it will do. (Trannies require a lot of research! Even then my info may not be right)

      [​IMG]

      either way, it pulls right out
      [​IMG]

      and then you remove the hub from inside it...

      [​IMG]

      and then you are left with a pretty normal looking cluch assembly... can you count the plates?

      [​IMG]

      (There are 6, upgrade kits can increase this up to 8)

      lastly you have the ring gear

      [​IMG]

      [​IMG]

      Now I don't have the output shaft so there are a few things you didn't see, and I didn't show the torrington bearings used throughout or some snap rings used in the case, but as a first glimpse, now you know what we will be working with.
       
      Last edited: May 17, 2006
    24. spindlecone

      spindlecone B

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      Glacier,is the dogear the part that engages when you put the trannie in park?
      always wondered what is engaged.
       
    25. Glacier991

      Glacier991 EF Tranny Guru Moderator Emeritus

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      No, actually, in the 4R70W is is pretty similar to the A4/4R and 5R. They lock on the output shaft. The 4r70W locks on the ring gear which is splined to the output shaft. Here is the ring gear cog for the parking pawl to engage

      [​IMG]

      and here is the pawl, in an orchestrated "engagement" (cueing up soft music)

      [​IMG]

      finally, looking into the bowels of the case (can I say that on EF?) you can see the pawl sticking in, as it would in park. ( do not even GO there!!)

      [​IMG]

      Anyway, that's parking 4r70W style, 101. Hope that answers the Q for ya!

      ps. thanks for the pan. Now I just need to figure oout where to put the drain plug in it. Suggestions?
       
    26. spindlecone

      spindlecone B

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