A4LD vs. 4R/5R55E,W,etc.

[93TwotoneXLT]

Let me start by saying that I am no transmission expert. I am just curious as to the opinions of the other members of the site. I am knowledgeable enough to know how transmissions work, but would never tear into one without an expert standing over my shoulder. Ok, to the point.

I have been reading the numerous posts on transmission problems members experience with their X's. I know that the A4LD has it's shortcomings in terms of internal strength/ability to handle towing and power in stock form. From what I read of the improved 4R/5R tranny's, they have stronger internals, but seem to have many of the same problems as the A4LD, and now are totally computer controlled. That of course means electronic solenoids to control everything, more complex valve bodies, computer trickery to get an extra gear(or two, with the latest version) etc.

I will offer my own opinion, which only goes off of my experience with automobiles(my own and seven years in the automobile industry) and is by no means expert. My A4LD is at 127K now, and is still going strong.(knock on wood) I have only flushed the fluid and replaced the tranny modulator. The truck is a stock 4x4 with no power mods. I can tell you that it was a one owner, and that the gentleman who owned it before me was older and never towed with it, and by the way the truck runs and seeing the valve train when I replaced the intake gaskets and such he never abused it. I know that the lack of towing is definately why this tranny is running as well as it is. It seems to me that with the A4LD's relative simplicity, as compared the 4R/5R, and after reading about the problems that members experience with both transmissions, that the A4LD in stock form is more reliable than the 4R/5R series.

No one may care about this thread, but I think that it may be interesting to see what everyone else thinks on the subject. If you are going to post what you think, please be sure to list year, mileage, tow/no tow, any major repairs, etc.

A4LD, 127K, never rebuilt, one fluid flush since ownership (18K), new modulator at 112K.

 

[Bent Bolt]

Well, I have to disagree with your option that the A4LD or more reliable that the 4R/5R trans. If you were to teardown a sample of the A4 and 4R/5R and spread them out on a big bench, you'd see that the are mechanicaly similair other than the valvebodys. Big differances are aluminum 4 pinion planetary A4LD and the steel 6 pinion 4R/5R. The other would be the needle bearing supports off the pump and center support in the 4R/5R-- much better than the A4LD.
Of course the valve bodys are differant. 4R/5R is computer controled which means much better control over shift points and quality. The 4R/5R does get a bad rap over the EPC issues but overall, thats really the only reoccuring problem that it has.

 

[93TwotoneXLT]

As I said, I know that the internals of the 4/5R are stronger. Basically I am asking which one people think is more reliable over the long haul in stock form.

 

[Glacier991]

I'll share my current thoughts an the A4LD, 4R/5R55E, then the W/S/N series. I am not claiming superior knowledge or insight,and others may well know more or have better ideas than mine. Anything you read on an internet amateur site should be taken with a grain of salt.... including my posts.

The A4LD was an attempt to morph an older 3 speed transmission into a newer 4 speed. It also was a foray into locking torque convertors electronically. For its time an interesting venture.

[Edit: As a sidebar, it is common to use an old design and update it for a new transmission. Why? The tooling and design costs and assembly line construction for a new design transmission run into HUNDREDS OF MILLIONS of dollars! So FORD's attempt to use the French built C-3 as a springboard is understandable.]

I suspect the design engineers were told to make a transmission for a soccer mom "station wagon" type vehicle, and given a limited budget to do so. Previously FORD had started with a C-3 and added an overdrive. With the Explorer they added a couple of electronic solenoids for limited computer control of OD and for the new lockup torque convertor. The A4LD version as Explorer owners know it was born.

Now as we know the Explorer changed automotive history. And the soccer Mom "station wagon" was never what the real world was for many explorers. The A4LD was a transmission being put to a torture test and failing. Between 1991 with the first explorers and 1994 when the A4LD was abandoned for the Explorer, it underwent many changes. Each designed to "fix" an earlier weak spot.

As is so often the case, before the A4LD fixes could be further fine tuned and we had a better idea of how successful they were, FORD introduced the 4R44E, then the 4R55E and the 5r44E and 5R55E.

These transmissions are kissing cousins of the A4LD, with several major differences. I'll refer to the 4R and 5R55E interchangeably, as most internals were the same. the 4R - 5R referred to the 4 speed versus 5 speed... the 44 versus 55 referred to torque handling capability. I never knew what the torque handling was for the A4LD but I am guessing akin to the 4R44E, or 440 foot lbs... [Edit: I was right, it is the same - 440 ft lbs]

Ok so now the differences. Biggest one mechanically? FORD put torrington bearings and needle bearings throughout in place or thrust washers and bushings... But because FORD also changed the valve body at the same time the improvements possible by the additions made to the transmission mechanically are hard to separate.

Now some editorializing. [If I may] Certain fixes to the A4LD are critically important ones. The rear planetary is weak. The 4R/5R increased that strength (as did the 94 A4LD). IMHO the sprags are undersized (in fact it was the addition of some sprag "teeth" that added torque handling capability as I recall) for their function and should be replaced on any rebuild. The front planetary also serves as the race for the OD sprag and needs a welded assembly... non welded races tend to spin loose in high torque situations. For all that...FORD only fixed the rear planetary in the 4R/5R (they may have added a couple sprag "teeth" I am not sure - making the 5R44 the 5R55.) The torringtons and needle bearings I think were a major improvement....but more than ever need clean fluid. Unfortunately... the fully computer controlled shifting in the new design valve body was a major new problem area... and tended to mask the improvement effect of the mechanical upgrades, inclouding torringtons and needle bearings.. BUT..The new VB and all electronic concept eliminated the governor, another problem spot. The 5R design changed the rear case parts and thus eliminated the A4LD rear case "wave washer" (a source of contamination in the A4LD becaise it tended to score easily).

Here is where a "frankentranny" is an interesting proposition. It takes the 5R guts, torringtons, needle bearings and all, and puts them into an A4LD case and controls it with an A4LD valve body.... a great test bed for the mechanical upgrades by themselves. I know of one in operation.... and I have two in my garage awaiting assembly.... WITH welded planetaries. (Frankentranny... the very name conjures up visions of arcing sparks and insane laughter...)

For my money the "frankentranny" is as strong as an A4LD can be built.... especially if you use a welded front planetary from the A4LD in place of the 5R55 planetary with the redundant (in this application that is) reluctor ring .

On the to stock 5R55E... it's major problems usually relate to either to the VB - mainly EPC but not exclusively, or to the front planetary. It bears noting that all these trannies suffer from the high heat of the CAT in close proximity to the OD and intermediate servos which tend to harden and leak as a result. The VB problems, especially EPC related ones,are legendary... in most cases, transmission "failures" are not the trans mechanical failures, but are the VB and EPC ! Way too many 5R55E's get rebuilds unnecessarily as a result.The 5R's are MERCON V trannies and need good clean fluid condition to operate reliably. More frequent fluid changes seem to help lengthen their lifespans as fresh fluid tends to have better frition modifiers.

None of them (A4LD, 4R or 5R55E) like towing much.

The 5R55E was redesigned and got a unitary case and a modular solenoid block and other internal changes of which I cannot speak with any knowledge really.... and became the 5R55W (W=wide ratio gearing) the 5R55S andthe 5R55N (I don't know what the S and N stand for - anyone?). The major weak point on these trannies is the solenoid block positioned the valve body. It often needs replacement as early as 60-75K miles. Mechanically... these seem to be ok....more needs to be known about their failures for me to offer more than that.

[Late edits:

I notice that in the case of the Low/reverse servo the 55W/S/N has gone to a bonded unit in place of sealing rings..... this has worked in the 4R70W well.... so this is probably an improvement.

I also see that the OD piston is now even larger than the ZC used in the 5R55E. Clearly the new case has a larger bore here. I am curious to know if they beefed up the anchors on the OD band as well.

Also they now have what is billed as an "intermediate sprag". How that all fits in bears investigation... something I have not been able to do so far. But if this picture is an indication, it is not a behemoth....

Looks like it lives in s stamped steel shell. (Ah for a 5R55W to take apart and play with)

..end late edits]

BUT.... No matter what subsequent tranny you look at...be it A4LD, 4R/5R55 E or W/S or N... a long ways from a 3 speed C-3.

Is that what you were looking for?

Glacier

ps. 224,000 on original A4LD.

 

[93TwotoneXLT]

Glacier, I was hoping that you would chime in. I read the frankentranny thread with great interest and agree that the mixing of the A4 case and the 5R guts seems to be the best arrangement. The only reason I posted this is because I have been doing a lot of reading on the net(not only here) about the new 5R55E,W,etc. From what I have read, they are stronger internally but that is offset by all of the computer controls.

From reading on this site I know that neither of these trannies, being nearly identical mechanically, are very good for towing. It does seem that members with later model A4LD tranny's(93-94) and tranny coolers seem to get good mileage out of their transmissions as long as they do not tow with them, or at least less than 1500lbs. Reading about members problems with the 5R55E trannies it seems that they can't seem to make it much past 100K without having to rebuild the VB, replace solenoid packs, etc. This is not meant to offend anyone out there with the electronically controlled trannies, and I am sure that there are some members that have well over 100K on their X's with the later trannies that have not had any problems with them.

Keep em comin'

 

[Glacier991]

for those reading, when Bent Bolt posts, it is worth a careful read. He is a FORD tech and VERY knowledgeable.... I learn from him most every time I read what he writes. Guys like him are gold in places like this and rare as hen's teeth.

He also has a very excellent knowledge of automatic transmissions... which, with all due deference I find an increasing rarity in FORD techs in the USA (He is Canadian)... so much so in fact I will put my knowledge on the A4LD/5R and 4R70W up against most American FORD techs (not all tho). Bent Bolt's knowledge surpasses mine.... and I *listen* when he writes.

 

[BrooklynBay]

Another thing to mention is that the modulator is gone on the 4R/5R transmissions. The governor was already mentioned. As for the longer life of the 93-94 A4LD, I would say that the 94 was the most updated with stronger parts. It was the last year they built them. Glacier, what do you estimate the torque rating would be on a Frankentranny? Would it be about the same as a 5R or better?

 

[Glacier991]

With case work and an added OD friction I'd feel very comfortable saying it has a torque rating AT LEAST equal to the 5R55E... or 550 ft lbs.

 

[8588ranger]

Chris,
So when will you start on your Frankentranny?

 

[BrooklynBay]

I'm also looking forward to that new diary.

 

[Bent Bolt]

I'll share my current thoughts an the A4LD, 4R/5R55E, then the W/S/N series. I am not claiming superior knowledge or insight,and others may well know more or have better ideas than mine. Anything you read on an internet amateur site should be taken with a grain of salt.... including my posts.


*** a whole mess of words here **********

BUT....A long ways from a 3 speed C-3.

Is that what you were looking for?

Glacier

ps. 224,000 on original A4LD.

Yeah, what he said !!!!! Pretty much sums it up. Glacier has much more skill at putting words to the screen than I could ever hope to develope!!!!

 

[Bent Bolt]

I am also actively looking for a 5R55E for my own Frankentranny project for my 87 Ranger. I am a little cheap so I am looking for a free trans.

 

[Glacier991]

I managed to score two 5R55E's pretty cheaply.... I have 3 A4LD cases, including a BRAND NEW shiny one.... ( For a Frankentranny I may need to replace the rear case bushing to get rid of the wave washer I'll have to see.... seems a shame, I admit). I have a brand spanking new A4LD Valve body to mod and use, and of course two sets of 5R guts to pick thru. I am super picky about my used parts, and so we'll have to see what I decide is useable. I will replace the rear and front planetaries and sprags, and use only a new pump.

What I currently lack is a 4x4 A4LD output shaft, extension housing, and a governor assembly. I hope to pick those up soon and start examining parts. I plan to machine the OD clutch for a 3rd plate - just as Brain did.

I am sure as I go along I will find other parts I am missing.... but I have the luxury of having a facility in Sacramento that tears down old trannies and will sell most any part you could need.... not cheap - about 50% of new, but they have it.

I fear that as I get this going I will get so picky I practically build this out of all new parts, like I did the 4R70W.... I am debating using it myself or selling it. If I was building it to sell, I'd probably opt for new in any close call about quality of a part.

I'm still on the fence about Kevlar bands. I wish someone smarter could either tell me my caution is warranted, or tell me I am full of sh*t.... I am not a believer at this point - not at 500 ft lbs and 3000 rpm anyway.

Interesting how this thread has morphed into a frankentranny thread.

 

[Bent Bolt]

What I currently lack is a 4x4 A4LD output shaft, extension housing, and a governor assembly. I hope to pick those up soon and start examining parts. I plan to machine the OD clutch for a 3rd plate - just as Brain did.

I am shocked !!! Thats not a O/D clutch. Thats the coast clutch!!

Sonnex has a repair kit for the low/rev sprag race. They have two differant sizes-- 2.8/2.9/3.0 and 4.0l engines. I need to look into if the 4.0l kit will work for the 5R55E rear sprag. Will look into the kevlar bands as well.

 

[Glacier991]

I am sure FORD will hang me for calling the OD clutch what it is. <g>. I routinely use the SOnnax rear race kit... and before you do know it does not fit unless ground down a little.... I mean to measure my 5R cases rear races to make sure, but I think the rear race in the 5R is the same size a the A4LD's. The 2.9 liter case is smaller than the 4.0. I have a 2.9 case I plan to convert by using the sonnax 4.0 - that seems to be the only difference.

Share what you find out about Kevlar bands.

 

[93TwotoneXLT]

ps. 224,000 on original A4LD


I am very interested as well in the frankentranny idea too. When/if my A4 dies I may see if Glacier would like to do the same for mine. Of coarse, I would hope that he would accept a nominal fee for his expertise.

Back to the matter at hand. It sounds as if everyone so far thinks that the 4R/5R is vastly superior to the A4LD. I respect that. So, since this thread seems to be getting off of the subject, here is a different question. Has anyone managed to get 200K out of the 4R/5R transmissions without having to rebuild them, or the VB, solenoid pack, etc.? This is not a question to rile anyone up, but I do think that it is worth noting who has managed to get real mileage out of the newer/better transmissions.

 

[Glacier991]

Sorry to have taken the thread off topic. There IS a thread on here regarding how many miles people got on their trannies...but your question is a good one.... the only problem is that many folks will curse and tell you theirs failed and needed a rebuild at XX,000 miles - but in fact maybe all that was wrong was a valve body or EPC... and they never knew. And hence castigate the mechanicals - which were fine.

 

[Bent Bolt]

ps. 224,000 on original A4LD


I am very interested as well in the frankentranny idea too. When/if my A4 dies I may see if Glacier would like to do the same for mine. Of coarse, I would hope that he would accept a nominal fee for his expertise.

Back to the matter at hand. It sounds as if everyone so far thinks that the 4R/5R is vastly superior to the A4LD. I respect that. So, since this thread seems to be getting off of the subject, here is a different question. Has anyone managed to get 200K out of the 4R/5R transmissions without having to rebuild them, or the VB, solenoid pack, etc.? This is not a question to rile anyone up, but I do think that it is worth noting who has managed to get real mileage out of the newer/better transmissions.

About a month ago, I overhauled a 5R55E out of an 99 Explorer that had 500,000 km and a broken band. Had original style valve body gaskets and no EPC blow off valve. I routinely see Explorers with 200-300,000 km . Can't be sure if the trans have been rebuilt.

 

[Glacier991]

In the A4LD's you could count stake marks around the bellhousing seal and know if it had been rebuilt..... not so in the 5R's.

 

[Glacier991]

In the polls section there are two threads.. one on how long did your 4r55E/5r55E last:

http://www.explorerforum.com/forums/poll.php?do=showresults&pollid=1065

And one on how long did your A4LD last:

http://www.explorerforum.com/forums/showthread.php?t=91391

From these unscientific polls one could assume the A4LD was a stronger tranny and lasted longer. What these poll results do not address is the WHY, and I suspect that the Valve body/EPC issues with the 4R/5R are influencing the result if the inquiry is about mechanical "stoutness".

I am of the mind that the 4R/5R is mechanically better than the A4LD.