How to: "My A4LD Rebuild Diary - Part 3, 2nd half - Reassembly

[Glacier991]

Well finally, eh? we are going to put this puppy back together. We've rebuilt parts fit parts, and now it's time to put the guts back in and button it up.

The transmission case is mounted to the engine stand once again. I'll start by putting in the reverse drum.. over my new race, and rotating it clockwise as I install it...

On top - in the snout - goes the planet carrier washer....the bronzie looking thing

and the I can put in the carrier....

Now I rotate the case to horizontal

I also have scuffed the shaft for better oiling....

And now I turn my attention to the rear of the case... the governor...
We'll start by putting the thrust washer in the base of the steel sleeved bore...

The governor body has steel rings on it....with funky locking ends.

Best way to get the old ones off is with a pick...

then put the new ones on... locking each one as you go (from the back please)

Then slide the shaft thru the body.....

and carefuly insert it into the bore....shaft going through the rear planet carrier....

Back inside now.... time to lock the shaft in place...using a NEW snap ring!

Make sure the ring found it's home on the fluted portion of the shaft and locks the rear carrier and the governor in place.... like so

and then add the oil dam.... a plastic cone...

installed

Next, time to add the rear planet. Need to put a thrust washer on back, and make sure it stays put as we install it... vaseline to the rescue...

and the washer...

and put the assembly into the carrier .. it should sit below the lip of the carrier...
(I've added the next thrustwaser on the planetary in this picture)

Next slip the rear band down around the rear drum .. paying attention to where the pins meet the anchor on the band...

Ok next post, to the center support.... MAIN GUTS

 

[Glacier991]

the rear sun shell, reverse clutch, forward drum and clutch assembly all fits together into HEAVY compact unit. (In later versions it locked together with tabs, not in mine) It goes into the case next. A little trick is to put a finger into the center hole and slide it in horizontally...

wiggle it until you feel the sun gear engage the rear planet, then move the case to an upright position. Insert the servo actutor "flipper" or "lever" (a "A") and its pin.... here you see the guts in the case and the lever...make sure you use the long rod on this lever. The OD uses an identical rod, only shorter. Don't mix it up or you'll be coming back to correct your error as the front pump won't go in if you try and put the long rod there.

It's center support time. Need to "size the seals.

 

[Glacier991]

Center support

This is a key part of this transmission. We have upgraded it and modified it, yet whether you do or not, there is one important thing here.. to add the right seals, and then "size" them. On our upgraded support the correct seals have a white band on them

Ok. What is "sizing"? It means making the seals conform and stay put for installation. How? By using the OD Drum!

lube that puppy up and "CAREFULLY" (avoiding any roll over - get the center support to go into it.... and bottom

Now. put it in the freezer! You heard me. What other fun things do you have in YOUR freezer?

Forget it for 20 mins or so. THAT is "sizing"

we'll add the intermediate band and then install our center support (takes about 20 mins first time - perfect)

 

[Glacier991]

Intermediate band

We soaked th band in ATF for an hour or more.... inserted it in the case around the drum.... now to place the anchors.... a long needle nose is invaluable for this.... here is the servo side

and here is the adjustment side....the screw

a little secret. Put the screw in and adjust i until it if flush with the inside... thenadd the anchor piece from the back, rotating it until it sits with the correct end over the pin... then screw the pin in and finally "locate" the piece...Here is what it looks like from the back

there is a special way to adjust this (non factory approved) that we will exlore later. (doncha just LOVE the intrigue?)

back to the center support. Brrrr....

 

[Glacier991]

center support-again

Out of the freezer.... ready to install. Ad the #5 bearing to the end... and carefully insert it into the main "guts" lining up the bolt hole wth the one in the case....

like so (The hole to the left is for a speed senor, which the A4LD didn't have in the trannie)

DANG. Now what did I do with that bolt and nut? Remember our baggies? VOILA. Payday!

Screw it lightly in place but do not tighten, yet....

The snap ring has a flat side and a beveled side. The flat side goes down..

Make sure it seats in the ring groove.... NOW you can tighten the bolt.

ASSEMBLED TO THE CENTER SUPPORT ! NEXT UP? OD !! And front ONE way clutch.

 

[Glacier991]

Governor again, for a moment

[Author's edit. This was a bad choice of time to do this. I would recommend that once you have the output shaft snap ringed into place in the case, that you do this procedure THEN. Why ? In my case the reverse band slipped when I had the case upsdie down.... caused a few anxious moments as I was 90% back together when I discovered it.... so.... do what I am showing, just do it sooner than later. Oh, and.... put the low/reverse servo in and put the cap on it temporarily once you put the low/reverse drum band in!! - end edit]



Since I have the guts locked in the case by the center support, I decided to put the governor on. So I flip the case around....

putting it on is a piece of cake... 2 bolts. I torqued them to spec... We upgraded the governor previously with a new spring and also a new "return" spring that FORD never had...here it is installed

here's looking at it down the output shaft

For the benefit of those only wanting to do their governor, I put the extension housing on the end of the transmission..like so

and here's looking down inside... you CAN extract the governor without removing the housing....

Ok, so enough of this... On to the OD!

 

[Glacier991]

OD Unit

This unit consists of the center shaft/sprag - the OD Planetary, a sun gear and castle washer, and the OD clutch and drum.... we will start ytaking apart the center shaft/sprag unit.. a snap ring holds it all together.

Peel it out...

Now the shaft part comes away from the planet outer ring part

Then the sprag

and finally the "tin plate" as I call it... I replaced this it looked a little shopworn and was cheap..

New sprag installed....

snap rings... old and new...

Assembled. Note position of tin plate stampings!

Now we can put the OD planetary into the sprag unit, twisting it COUNTERCLOCKWISE(see arrows!)

add the gear, cut side up...

and then the infamous "castle washer" It has a "printed side"

Install printed side DOWN

then add the OD Drum/clutch on top.... make sure it seats on the castl washer..

The OD is IN !.... next... front case clearance....

 

[Glacier991]

Front case clearance

Just as we needed clearance in the rear half of the case....we need it in the front as well.... .007 to .0024. We will install the pumpo and the old thrust washer.... and measure... Pump in (absent sealing rings....pops right in)

Then using the factory gauge bar....

I measure

and first result on this side is...

180 degrees away I again measure

and this result is

so around .004.... tight... but! I have a washer installed....before we explore that let's try the home made tool....the pine bar....and compare. I'll spare you details and just superimpose which end I used with results... first end

second end..

exact same. Home made works.

Now we had a washer installed.... how thick was it? Measuring....

According to the chart... .070 is....

a number 4. Wait, it says the number is stamped on the ear!.... let's look....

Coolness, all this works! (exactly how I discovered it too)
Ok let's think. we are at .004. The min is .007, I want a LITTLE more than that... so my choices are? look at the chart again

the next lower, #3 only adds .004 so we are JUST within specs.... the next adds another .004 up to .012... I like it.... part no for a number 2 ??

and the ear ? Does IT say 2 ?

Eureka! Does the math work? what IS my front case clearnace with it installed? First side reading (remember to minus the gauge bar .700)

2nd reading...

ok... 012 front clearance.... I like it. ready for front pump and bellhousing.... the bellhousing is at the machine shop, will pick up next wek when I get it back....

 

[Brain]

Hey Glacier, I think I saw a problem but I can’t be sure because of the focus of the pictures in the previous post. Check out figure 5 (the last one) and the last sentence from the following TSB:

http://www.alldatadiy.com/alldata/A.../56351048/34853741/34850750/42063452/42467408

I think you might be using the pump gear for a 4R55E (because I can’t see the sharp edges on the inside bore of the inner pump gear in your pictures), which would cause premature failure of the front bushing and seal. I noticed that the Transtar online catalogs have the same part number listed for both the A4LD and the 4R55E, which is incorrect (and possibly why some rebuilds fail at this location – wrong pump gear put in because the vendor said it was the right one). K27201B is listed as the part number for both…which we KNOW is wrong. I was looking at that issue the other night and I thought this would be the right time to bring it up (before you checked and installed the bell housing). I’m curious if it is the wrong part of if my eyes are deceiving me, so let me know.

On a side note, I posed the question I PM'd you with to Omega Machine and this was the result:
Question: I was wondering if you could answer a question for me. I know that the A4LD had it's bell housing bushing finished in place, but I was wondering if that practice continued through the 4R55E and the 5R55E. I know Ford redesigned the bushing lube circuit for the 4R55E to give better lube flow and longer bushing/seal life, but I don't know if they changed the manufacturing process to deal with the problems that they were having with the bushing being off center. Any help would be greatly appreciated.
Answer: My understanding is that most OEM bushings are finished in place. That is one reason many bushings are not sold separately by the dealers. I'm not sure if that is the case with the 4R55E etc. but it would be my guess.

So no definitive answer to this question...yet.

 

[Glacier991]

Brain... I'll check, but this was a new FORD pump purchased from Torrie at FORD PARTS NETWORK...and is an A4LD pump. I think everything should be kosher in it - but! I'll check and post what I find. I'm not at home where I can do that right now. Thanks for the sharp eye! Thanks for the link... the possibility of putting a 4R55 front end (pump/bellhousing) hadn't occurred to me, because I had no idea they had made any changes..(I keep learning new things on this voyage)..something to consider.

 

[Brain]

How do you get the $#*@! rear sprag out of the reverse drum? Mine has a plastic outer cage with six tabs on it, and I've tried carefully prying and coaxing, but I'm scarring up the plastic :frustrate. This makes me wonder how I'm going to get the new one in, unless you have to get the rear drum with the sprag already installed. How did you do it Glacier?

I also noticed something that I'm not sure is a problem or not. On the overdrive sun gear, there is a bearing race that came out of the old planetary assembly to expose the bearing underneath. The new one doesn't have any exposed roller bearing (it comes with an enclosed bearing, like Glacier's), but I was wondering if the bearing race that fits up inside the sun gear is still needed?

I've decided I'm going to try to create "Frankentranny" using the body of a A4LD (w/ the updated center support and bearings), the bellhousing and seperator plate from a 4R55E (better front bushing lube and longer front seal life), with an 5R55E pump and gears (the one with a bearing for the overdrive basket). I've never heard of this combination before, and it might take some rework of the overdrive unit, but it seems like a worthwhile attempt. Since my OD failed and took out everything listed except for the bellhousing, I'm only expecting to spend an extra $40-60 on the changes - worth a try IMO. I'll let you know what has to be done to make it work (it looks like there is no fear on this board about machining parts that need it for improvements).

 

[Glacier991]

Brain.. I don't recall if I found a suitably sized bearing tool, or used a large brass pin punch, but by alternatingly lightly hammerring, the sprag isn't all that tough to get out. I DO remember thinking to myself that I was glad I wasn't going to be reusing it, the plastic outer ring did get kinda messed up. The new one I could press in with my fingers.... the plastic tabs that more or less held it in place would be unnecessary once it was in place in the trannie.

I'm not sure what you are asking on the sun gear roller bearing in the planetary... the old and new looked alike in mine. Can you be more specific?

Lastly... I think the 4R bellhousing and separator (and pump) may be a good idea... based on your research (I never thought of that until now)... the 5R pump MAY give you some problems potentially.... the OD drum *I think* underwent some changes which may or may not be backwards compatible. They increased the size of the clutch piston (hence fewer plates needed) and how that plays out in a backwards compatible sense I do not know. Keep us posted. I vaguely recall being excited about a roller pump bearing into the OD drum and coming away frustrated that it was "not backwards compatible." I'll check through my stuff to check my recollection... (Also I think people will say things are not backward compatible when in fact they may be with some ingenious tweaking)

 

[Brain]

On the sun gear, never mind...I tried to put it in the new and it absolutely will not fit nor is there clearance between it and the planets, even if I could get it in. Sorry.

 

[Brain]

I figure that if you are able to use the 5R frictions in the OD, then they can't be all that different. If they do have a bigger piston area, all the better (more holding power). Like I was saying, since my OD unit was the thing that got toasted (drum, piston, springs...everything including the pump), I really have nothing to lose by trying because the cost differential of the updated parts for the different models probably isn't that much. Now that I think about it, how did they get a bigger piston in there and use the same size frictions?

 

[Glacier991]

Brain.... first off... WOW are you observant. The gear in the new pump IS (or at least MAY be) the 4R55 gear!!! ... I'll post comparison pics later tonight in this post. THANK YOU for picking up on that. If if fact it is, then that fact alone MAY explain a lot of the rebuild front seal failures! Good eye - I mean *I* went back and looked at my pics and didn't pick it up! However, that said... I find it curios that Alldata says that the 4R's have an O ring seal in the gear... there's no place for one in this gear.....yet it lacks the obviously channels their diagrams show.... more research needed to definitively answer this one

2nd... I think there was a design change on that sun gear bearing. I have some pics of that too I'll post here later. But I think additional washers are unnecesary. That sun gear is constrained concentrically by the planetary gears, AND the input shaft. And the new thrust surface seems pretty well locked in place within the bearing.

Lastly I am looking for my info on the 5R OD drum... meanwhile.... be my guest to ferret this one out. I may have gotten jaundiced and given up too early on the 5R stuff. Go for it. How they could have increased the piston and still made plates that fit? Excellent Q. Maybe my info is wrong. Love to see side by sides with things mic'd.

Anyway pics coming up....later.... Thanks for the interaction - exactly what I was hoping for... a collaborative rebuild as best we can.... but WOW, your catch of the pump gear blows me away man!

A question for YOU. The A4LD, in the 4.0's on the double wrap band used an OD "C" apply lever (up to '91). The 5R uses an "A", same as the intermediate. My looking at them - A beside C - suggests the A applies a greater leverage (based on simple physics) Does the single wrap band use an A? If not, would going to an "A" for the OD band servo apply lever be a wise move ya think? Seems so to me..... but.....

 

[Brain]

That's kind of what I was thinking about the rebuilds having front seal failures. Glad my eyes weren't decieving me...I just couldn't see the sharp corners in the I.D. of the inner gear and remembered it as being important for lubing that front bushing. Then when I was cross referencing part numbers for my "Frankentranny" I noticed that it was the same part number - that issue has been stuck in my mind for some weeks now, so I'm glad it was of some use to somebody other than myself.

To answer your question quickly, yes. I believe your "C" lever was used for a double wrap and had more travel/less force, and the "A" was used with the single wrap that gave less travel/more force. My '92 had a single wrap band and "A" levers on both the intermediate and OD. So they have the same anchor and adjusting bolts, same band, same stake from the band to the lever, same lever, and a bigger servo piston on the OD.

 

[Brain]

Since it is an issue (and has been for a while apparently), I decided to take a closer look at the components to see if we can improve the design and improve the life of the front bushing and front pump seal (the one that costs $8 but takes $600 worth of R&R to replace). In this particular part of the system we have: the converter shaft (powering the pump by fitting inside the small pump gear’s inside cutout), the pump gears, the pump body, the separator plate, and the bell housing. I'm going to try and also explain this so others understand why it is very important to not get the wrong inner pump gear.

The pump body has a hole bored in it where the fluid comes in from the high-pressure side of the pump and fills a channel around the back of the small pump gear. This hole is located right where the inner diameter of the small gear sits flat against the cutout portion of the pump body. The pump body has a channel groove cut around the diameter, right next to the shaft that the torque converter snout fits around. This channel is to disperse fluid around the entire back side inner circumference of the small pump gear. The fluid is then forced through the cutout portions of the inner gear (the pathways left between the cutout of the small gear and the converter pump-driving shaft). If you want to see how much area the fluid has to flow through, just place the small gear on the snout of the torque converter.

If there are no cutout portions (a perfect fit with no gaps), then there is no free path to move the fluid through to the other side of the gear. This is where I suspect that several rebuilt units have had problems to to parts mis-matching. The fluid needs to get to the other side of the gear because it then is dispersed around the chamfer (bevel) of the small gear on the front side (assembly instructions tell you to place this chamfer towards the bushing), passes the separator plate, gets forced forward through the bushing in the bell housing, and ends up at the front seal. Then it completes the journey by flowing around the converter shaft to the drain-back hole in the bell housing (which Glacier has shown how to enlarge for better flow and is also shown in a tech bulletin given at the bottom of this post), getting squirted out of the hole in the separator plate and the matching hole in the pump body, draining through the tranny case, and eventually going back to the low-pressure/suction side of the pump (through the filter and pump pickup).

If any part of this pathway is blocked, the bushing and seal are going to be starved of lube and won't last as long. The later versions of the A4LD (renamed the 4R55E and the 5R55E) don’t try to get from one side of the pump’s small gear to the other by going through it, they decided to go around it instead (but it has to take a pretty long journey to do it). Because the 4R55E started the “new†way of going around the gear to get to the front bushing and seal instead of through the gear, the small gear could fit tightly against the converter pump shaft, with or without an o-ring.

Now, on we go with the possible improvements. We already know that the drain-back hole in the bell housing is supposed to be enlarged to aid in getting old/hot fluid out, but what else need to be enlarged, and how do we get more fluid in?

Possible Modification List:
1) We could enlarge the drain-back hole in the separator plate and the pump body. This completes what Ford started with the bell housing modification.
2) We could take a Dremel or other rotary tool and make the dispersion groove in the pump body deeper/wider/smoother to allow a larger flow pathway leading to the four passageways through the small gear.
3) We could cut the chamfer (bevel) on the inside of the small pump gear a little bit taller and maybe a tiny bit wider to give a larger pathway once it gets past the small gear. Completing this thought is enlarging the separator plate hole the same amount as the bevel is cut back so that the separator isn't a knife-edge blockage point.
4) The last, but most important thing I can think of (short of re-boring the pump body) is making the four passageways through the small gear larger. I wouldn’t take out any on the flats, as they are what supply the torque to the pump, but I don’t think that judiciously removing a little material going to the round part of the inner diameter of the gear would hurt the structural integrity. It is possible to do just two for increasing the flow area around 50%, or all four for double the flow area. More flow area at the same pressure will give more flow.

Can these modifications be overdone? Absolutely. Fluid pathways that are designed to stay separate need to stay separate. The small gear still has to have material to ride against (both on the separator plate and the pump body). But the most important thing about overdoing these modifications is that any increase in flow to the front bushing (by decreasing flow restrictions) will lead to a decrease in flow to the rest of the system (running the band servos, clutch packs, shifting, etc.). Fluid will always take the path of least resistance, so it is a balancing act of getting the "right" amount of restriction in any flow pathway under varying operating conditions.

One of the reasons the original design is lacking is because the fluid has to change direction from forward to spinning to forward again – kind of like trying to jump on a merry-go-round. It takes effort, and in this case the effort is supplied by pressure – a pressure that could be better utilized by forcing more fluid through the bushing (keeping the front seal cooler), which is why the 4R had a direct feed path that runs behind the separator plate in the bell housing. Sorry about the rambling, but Ford should have included more modifications in their tech bulletins than just enlarging the drain-back hole in the bell housing, or even better yet they should have issued a revised replacement part. The other parts of the fix require more skill than just running a drill, which is probably why they left them out.

I’m drawing these up and can e-mail them to somebody so it can be posted. Maybe Glacier would want to do these modifications, posting pictures with explanations.

Here's the link to the drain-back hole modification from Alldata:
http://www.alldatadiy.com/alldata/A.../56351048/34853741/34850750/42063452/42467412

 

[Glacier991]

Brain.... you are right that the small gear cut without the elongated flat is a darn good fit on the torque convertor... not much, if any oil is going to get past it (I'll try and get pics of this). I checked with FORD and they say the pump and gears are what is shown as current manufacture for the A4LD - the body certainly is right. This is wierd.

I think your idea of holes in the gear is interesting, but they would have to angle into the center, since the little "well" around the shaft is where the oil comes from. straight through would just result in little oil as the gear rests up against the body of the pump in that location. It may be easier to just dremel some oiling groove or grooves in the small gear... I'm still debating.

RATS, about ready to finish it up and then THIS ! <g>.

 

[Brain]

I didn't mean holes, just enlarging the channels that are supposed to be there to give more area...just like what you are thinking. If you PM ne your e-mail, I can send some drawings of what I'm talking about.

 

[Brain]

Alright, I did the mic’ing and came up with the following numbers:
1) Flow area through the inside four corners of the small pump gear (assuming the TSB is correct and that the four lube channels are present): 7.68 to 7.72 square mm
2) Flow area through a modified ¼†bell housing hole (I just read that the pump and plate drain-back hole should be modified to 5/16â€, so the ¼†in the bell housing is the smaller flow area – something new to me): 31.7 square mm
3) Now assuming that the 0.003†maximum clearance between the bushing and the converter snout is the worst case, applied all around the converter snout, the flow area through the bushing: 9.79 square mm - I used a value of 40.84mm for the snout diameter (because that’s what mine mic’d)

Now my assumption would be that you would want the bushing flow area to be the controlling restriction, but in this worst case of bushing wear, it isn’t. The area to get from the back of the small pump gear to the front of it is the smalllest (and non-existant if it doesn't have the channels).

Something else that bothers me is that the tech bulletins call out for a clearance between the converter snout and the bushing of no more than 0.003â€, yet in another bulletin they state that 0.010†of converter snout runout is OK….????? Those clearances/tolerances don’t seem to work together. A clearance of 0.005" would allow a snout to runout a total of 0.010" with the snout just contacting the bushing, but if the clearance is 0.003" then the maximum snout runout would be 0.006", or about 3/5 of what they state in the bulletin....

Here’s the TSB for the 0.003†clearance:
http://www.alldatadiy.com/alldata/A.../56351048/34853741/34850750/42063452/42468823
And here’s the TSB for the 0.010†allowable runout:
http://www.alldatadiy.com/alldata/A.../56351048/34853741/34850750/42063452/42467399

What the heck are they smoking??? It ain’t tobaccy!