How to: 4R70W Rebuild Diary Discussion, Questions, ETC

[Glacier991]

In an electronic shift transmission, the computer (PCM) will command shifts based on input conditions... it uses an array of sensors... speed. engine condition, etc... sensors to decide when it is appropriate to be in which gear. As we come forward in time more and more sensors are involved.

The Transmission tester plugs into the transmission in place of the computer.... and lets you manually select gears. On a tester device in the ****pit.... so instead of the computer shifting gears for you, you direct the transmission when to shift. The beauty of this device is that you can see if the transmission is doing as it is told to do, or whether is os gettng "bad advice" from the computer. I have one I loan out... and it is well travelled.. They are not cheap, and I do not send them out blindly, and require a deposit to cover the cost of replacing it, and my time to do so. I have two and one has several thousand miles on it.... but they are golden in deciding what is a transmission problem versus an input/computer problem.

 

[BrooklynBay]

The transmission tester is electronic. It sends out a modulated signal to the EPC, and TSS solenoids. The older TCC solenoids, such as on the A4LD were only on, and off like the 3-4 shift solenoid. The shift solenoids are either on, and off. If you read the A4LD diary, you will see some information about doing a "click test". The tester basically sends out a series of simulated signals to test all of the solenoids as if the PCM were sending the signals.

 

[Glacier991]

That is in the bench mode.... in the drive mode, it will actually allow you to manually command shifts while driving. So you can see if the transmission is doing as it is told.

 

[BrooklynBay]

I wonder if this tester could be modified in some way to be used as a controller for a transmission when a newer transmission is swapped for an older one?

 

[Glacier991]

VERY manual... not a likely candidate.

 

[cknorw]

I have driven now about 300 miles, transmission is working perfectly. I'm thinking the issue of changing from 2nd thorugh 3rd into 4th may be in the programming logic in an attempt to get into final drive quickly to maximize fuel economy. I have a friend with a 97 Grand Marquis, same transmission, that does the same thing. Seems to weird two transmissions would have the same problem. So maybe its suppose to work that way?

I have also noticed a slight maybe 1/2 second "zzzzz" or buzz when starting out after cranking. It happens at 10-15mph. Its done it in second gear and 1st gear. I even cranked on a downhill and coasted in neutral up to speed and it happen. The sound or feel doesn't happen in a specific gear. It only happens after cranking and getting up to speed the first time. At no other time do I hear/feel it. I wonder if the ABS is the culprit, not that its a problem. Any thoughts.

 

[BrooklynBay]

I saw this picture on WWW.FordFuelInjection.Com, and thought that it would be useful to anybody that is working on it:

 

[Glacier991]

Nice post BB ! Thanks.

 

[Glacier991]

Well as temps cool off I am about ready to finish up the Diary threads to their conclusion. I have been working on it a little and have a nunber of pics awaiting editing and uploading.

I am workiong on some some potentially exciting developments as regards the VB portion... when I can, and if I can, I will share what I have in the works.

 

[cknorw]

I think I can finally certify my transmission (as certifications go for a rookie rebuilder). The grinding/buzzing/zzzzzzz sound (actually more of a feel), did turn out to be the ABS. I have not read much on it, but the ABS must go through an activation process at about 10-15mph the first time you accelerate after starting. I disconnected the power and to it and... no grinding. Never noticed it before I rebuilt the transmission.

Glacier, thanks for all the info you provide, especially the thickness (.700) of the bar used with the depth micrometer. I was able to borrow one from a machine ship, but only the micrometer. I had to improvise on the bar. Until I had the thickness of the bar, I had no way to know if my depth was right. I found lots of places the question was asked, but never an answer. (I felt like it was one of those questions that if I ever found out, I would have to be killed). It was also a big help to see everything in a transmission broken down, affording me the opportunity to see what I was getting into. It was especially nice to be the exact transmission I have. I entertained the idea of rebuilding the transmission for about 18 months. Never thought I would do it or be sucessful doing it (sure made it a lot easier replacing the freeze plug on the back side of the head too).

I spent 8 weeks on it. I enjoyed the project (even more so since it works). Now that I've done one, its amazing how many people find out and want me (the expert of course) to look at theres. Maybe.....

 

[Glacier991]

Thanks for the update! I have said over and over that people are too easily put off by auto transmissions, and that was why I started the Diary series. And yes I know what you mean about voids in information. I have tried to fill those.... apparently with some success.

Congrats on the successful rebuild, and you and now an official "expert". Feel free to help others doing their own on here and elsewhere... because... you truly ARE an expert now.

 

[jamichelli]

Question that I have...I think my tranny is the 4r70w (96 XLT 5.0) that just started acting up a couple of days ago. I have tried posting to the 911 forum, but I guess my account is not activated(?). Anyway, this is an account of my problem:
Put the selector into D, the tranny will shift once then rev up until I hit somewhere between 30-40 mph. After this, the tranny lets go and I coast down until back down to a crawl before it will acelerate again. In the other forward gears, there is no shifting at all. What could be the culprit of this? 2nd SS? Clutch pack? This is a daily driver family vehicle and the sole means of kiddie hauling...in other words very much needed! TIA

 

[Dave B]

Rebuild kit

I will just have a general thread where they can post comments, ask questions, etc.

I would be interested in your used, good 4R70E parts. Please contact me if you are interested in unloading some of them...

dburton at nwlink.com

Thanks,
Dave

 

[Turdle]

Ok guys

If you want this info to be easily acessable in the future--
please go rate this sticky----

http://www.explorerforum.com/forums/showthread.php?t=128800

 

[Glacier991]

and turn it back into one.

 

[Bent Bolt]

Question that I have...I think my tranny is the 4r70w (96 XLT 5.0) that just started acting up a couple of days ago. I have tried posting to the 911 forum, but I guess my account is not activated(?). Anyway, this is an account of my problem:
Put the selector into D, the tranny will shift once then rev up until I hit somewhere between 30-40 mph. After this, the tranny lets go and I coast down until back down to a crawl before it will acelerate again. In the other forward gears, there is no shifting at all. What could be the culprit of this? 2nd SS? Clutch pack? This is a daily driver family vehicle and the sole means of kiddie hauling...in other words very much needed! TIA

Doesn't look like he's around anymore but I'll reply to it because this is a common problem with the 4R70W

2 things can cause this, both have to do with the 2-3 accumulator. First and most likely is that the 1-2 accumulator piston has failed or worn out. Symptoms are 1st gear normal. 2nd gear normal but does not shift into 3rd, stays in 2nd. At about 60-70 kph, trans neutrals. What happens is that the 2-3 accum piston wears out, prevents the direct clutch applying-- no 3rd gear. In 4th gear, the forward clutch comes off-- but the direct hasn't applied yet-- and the trans neutrals. If you get the trans repaird soon enough, internal damage can be prevented.If not, the direct clutch gets burnt.

The second problem is the 2-3 accumulator spring breaks. Has same symptoms. When the spring breaks, it can score the case. Big $$.

The valve body has to be removed to replace the piston and spring.

 

[Glacier991]

Am getting back to work on the Diary and will finish it shortly.... with new and improved info throughout. (and links that actually work).... but I am starting to get inquiries and i wanted to pose a Q...

Many do not have access to the tools to rebuild clutch packs, etc...and are asking me if I would do theirs for them and send them an installable version (mainly direct drum and forward drum... also input shaft seals and output shaft one piece seals...)

Is there a serious interest in that... being able to swap out your old for installable new? I might consider building a bunch to do that with if there was an interest.... haphazard now and then one in a blue moon, no.

So, is there an interest in installable hard parts for the 4R70W?

 

[Turdle]

Am getting back to work on the Diary and will finish it shortly.... with new and improved info throughout. (and links that actually work).... but I am starting to get inquiries and i wanted to pose a Q...

Many do not have access to the tools to rebuild clutch packs, etc...and are asking me if I would do theirs for them and send them an installable version (mainly direct drum and forward drum... also input shaft seals and output shaft one piece seals...)

Is there a serious interest in that... being able to swap out your old for installable new? I might consider building a bunch to do that with if there was an interest.... haphazard now and then one in a blue moon, no.

So, is there an interest in installable hard parts for the 4R70W?

I say yes--
It is bound to come for me sooner or later--

 

[Highroller]

Sorry if this question seems too general, but my '97 5.0 2wd X is coming up on 200,000 miles and even though the tranny seems find I would like to do a light overhaul. Any suggestions on wearable parts needed for a job like this? I am adding power to this old thing and will have the motor out for a refreshening, so figured the tranny could use it!! Note: Will be adding MAC pan and extra front mount cooler w/inline filter...thanks

 

[DieselAvenger]

What thickness is the AOD gauge bar for measuring the selective thrust washer?