4R70W Rebuild Diary - Part 13 - Intermediate Clutch | Ford Explorer Forums - Serious Explorations

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4R70W Rebuild Diary - Part 13 - Intermediate Clutch

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Glacier991

EF Tranny Guru
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The intermediate clutch in the AOD-AODE-4R70W is an interesting creature in that there is no housing for it per se. Once you have assembled everything in the transmission and are ready for the pump, you install the pressure plate and frictions and steels on top of the "mechanical diode" and the back side of the pump houses the piston to actuate the clutch. The frictions spline onto the "mechanical diode" and the steels ride in the case.

So, in reality, it consists of a pressure plate, steels and frictions - and there is a steel that is "selective" - available in .069 -.079 - .089 and .099 thicknesses so you can adjust the final build up. This clutch was made in a 3 plate version up until about 1998, and later a 4th plate was added. We will be using a 4 plate friction.

FORD offered a couple different fritcion materials, one grooved and one not. Jerry W discusses this in his excellent article on page 10. Since he wrote that the friction materials from FORD changed again.

I had purchased an ALTO upgrade kit for this clutch, with smooth frictions and Kolene steels and a 4 clutch presure plate. I had also found a 4 clutch pressure plate from FORD. AND, I ordered the newest FORD friction material that had grooves.

Let's make some comparisons.

Here is the ALTO pressure plate on top of the FORD one....

DSCN6829.JPG


Here is the ALTO pressure plate thickness

DSCN6832.JPG


And here is the FORD

DSCN6834.JPG


Alto picks up a little clearance. The ultimate clutch pack clearance is adjusted by varying the thickness of the last plate. FORD offers four (4) "selective" thickness plates. they are 69 thousandths, 79, 89 and 99. A stock plate is right around the 0.069 measurement. Here is a stock plate (left) and plates #3 (89 thou) and 4 (99 thou)

DSCN6835.JPG


I like to double check things... so here they are, #4, #3 and #1 ( I have a #2 somewhere just misplaced it during the photo shoot)

DSCN6836.JPG

DSCN6837.JPG

DSCN6839.JPG


The last one did measure 0.069 but as I photographed it I looseneed the pressure apparently.

FRICTION MATERIAL

In his article Jerry W mentioned that in 98 FORD upgraded the friction materials, and gave the FORD part No of F75Z-7B164-CA for the frictions for this clutch. When I went to the dealer they said the number had changed (meaning another upgrade) and the new number was:

DSCN6841.JPG


I opened the package today to photograph them for you and there was a faint product number on the plate. It was not easy to read, but once photographed I found out something interesting (This was a sealed package from FORD btw)

DSCN6842.JPG


an entirely DIFFERENT part number! (Also notice the grooves) I cannot explain, other than to "guess" that they changed the material for the 4R75W and are using up old packaging. These are pricey... $9.21 each.

Here is the Alto HP upgrgade friction.... notice the lack of grooving....

DSCN6843.JPG


The thicknesses are nominally the same. My choice here? FORD. Grooves.

The Alto kit comes with Kolene steels. THOSE I will use. Thickness? Nominally 0.069 in. (Steels have some variance about + or - .002).

Next time you see these we will be installing them.

PISTON


Oh, I did pick up a bonded intermediate piston from the 4R75W and thought I might explore using it. To do that I need to turn to a pristine used pump and see if it might fit.... We need to disassemble the back end and see how the intermediate piston works... So, here we go. Back end of the 4R70W pump... the BIG dots point to the spring locations. the smaller ones point to the piston...

DSCN6847.JPG


The spring retainer is held in place by 3 small "clip like" things...they are at each spring location and can be released easily with a screwdriver or other suitable tool

DSCN6849.JPG


here it is released - you can see the srpings.... weak by many standards..

DSCN6850.JPG


As you remove the retainer you can see the springs...

DSCN6851.JPG


Here is the piston spring retainer off...

DSCN6852.JPG


The lovely battleship gray background is my garage floor.

Next we can remove the intermediate piston from the pump...

DSCN6853.JPG


Here are two views of it out...

DSCN6855.JPG

DSCN6858.JPG


.... OH, the "bonded piston" ? Won't work.

Now, and this is important.... the bleed hole in the piston needs to go at 12 o'clock in the pump... that would be the part of the pump that will be at the top of the transmission once installed.

First let's define what is the "bleed hole". Here it is on the side of the piston that goes INTO the pump:

DSCN7375.JPG


I do not know that there was a special place where they drilled it vis-a'-vis the stamped numbers... but now you know what size that hole is... And , it comes out in the hole (the ONLY round hole) in a raised portion of the "apply side" on the reverse:

DSCN7376.JPG


Now this is the pump, naked, without the piston, clock position.... 12 at top:

DSCN7377.JPG


and here is the piston, loosely placed as it should be with the round hole in the raised portion (the weep hole) ALSO at 12 O'clock:

DSCN7378.JPG


MAKE SURE YOU DO THIS. THIS ORIENTATION IS IMPORTANT!

That is it for this post on parts of the intermediate clutch....EXCEPT....for a teaser... final case clearance depends on a plastic washer on the pump.... here is one from a used tranny.... being removed...

DSCN6861.JPG


When we put the pump in we will select the correct final thrust washer for this spot.

Next up, installing the intermediate clutch! Wierd creature.
 



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Time for some more info. We are here at the intermediate clutch in the rebuild.

What I discovered(1) was that the space to assemble your clutch was NOT dependent on other aspects of the build (in other transmissions the clearance is dependent on other parts which may vary causing a variance in the final measurements obtained, not so here... this area is set by the case machining! - It is a fixed amount of space.) You have a space ofabout 2.500 in which to assemble a clutch that needs a final clearance of ....1.634 to 1.636 according to ALTO (a major aftermarket transmission clutch maker) or 1.634 to 1.677 according to FORD.

I have noticed that ALTO likes a much closer clutch pack setting. I am also mindful of Jerry W's admonition to tend towards the higher end of these things.

What I found was, that because of the set clearance to start with, I could adjust my clearance on the bench by selecting my clutch pack.

I had 2 pressure plate, FORD and ALTO. ALTO was .010 thinner. AND...If I went with the full ALTO setup I was nearly .070 too thin! (The measurement was around 1.710 or so.)

Thicker steels dissipate heat better. I needed my clutch pack to be thicker... So... first choice, the slightly thicker FORD pressure plate. By using this I have picked up .010 in my clutch pack thickness.

The Kolene steels average about .069. Yet, I needed to pick up some more thickness in my clutch pack. The thickest FORD plate (A selective designed for this purpose - but not KOLENE) was nearly .100. So by using it as the top plate, I pick up another .030. Down to .030 over the ALTO pack clearance suggestion of 1.634 - but within the upper limits in the FORD specs. I have tentatively decided to stay there. I'll show you the results in the next post. And how I measured all this.

Oh and I will add a post coming up next on how you adjust end case clearance - without an H gauge! We are closing in on it !
 






This was one part of my rebuild that I did not even give a second thought. Did not have any way of mesuring clearances. I replaced the old frictions with new and accidentally used a thicker selective plate. Well I bolted the pump on and the thing wouldnt turn over by hand. Pulled the pump and went with the next size down till i could turn it over by hand with the pump installed. It will be interesting to see it done the right way. I am amazed my rebuild is still running with all the corners i cut to save money i didnt have.
 






Actually your practical, intuitive approach makes a lot of sense! I am sure your smart approach played into all other parts you rebuilt.

I ran into folks in the A4LD diary complaining I was being too "by the book" etc. I promised but never have yet delivered what amounted to a "seat of the pants rebuild diary for shadetree mechanics for the A4LD." So, I won't promise one here, but the 4R70W (unlike the A4LD) can be rebuilt to a decent level reasonably inexpensively... But, that said I will add ... not to THIS level of build or stoutness.

I hope you will continue to add your thoughts and observations... this Diary is rather like a desert.... people read the initial thread... and stop. For the rest I have a select audience, so it was nice to see your post !

ps. My digital caliper can be purchased for $16 plus tax at HF. NO reason not to be able to measure.
 






i am replacing my direct clutch and couple other things (seal rings) etc... I have been following your dairy and threads everyday. awesome stuff man. really appreciate the posts and im sure everyone else will find your dairy awesome and very helpfull!
 






Thanks for your kind words! I try and provide a detailed step by step with photos, something not even the FORD manuals manage to pull off without some gaps.... and as I encounter new stuff that puzzles me I try and document it even more fully so those following have an easier time of it.

This Diary by far is the most complete and well organized I have done to date.
 






Let's look at some pictures to illustrate what I am talking about.

First, using the AOD gauge bar (from the 1980 tool set - available for loan with deposit - and which is .700 thick as in the ase of the A4LD) we can meaure down to the surface the inner end plate rests on.

DSCN7044.JPG


As I have said this measurement is a fixed measurement.... and it comes out as

DSCN7046.JPG


I measured this at several points and it varied slightly - probably my fault... not perfectly vertical etc....but I will use 2.500 as the benchmark. Per FORD we are looking for 1.634 to 1.677 as the end result after a clutch pack goes in. Doing the math... 2.500 - x = 1.634 to 1.677. A? .823 to .866.

We have a clutch pack that consists od the inner end plate, 4 frictions and 4 steels. Here is a picture of such a pack...

DSCN7043.JPG


The little sideways arrows show the depth measurements I was able to adjust by selection. The lines are to the frictions. Kolene steels start out black, so you can make out the 3 Kolenes. I am using the thickest FORD selective on the top end (right hand side in this picture) of this pack.

The measurement of this set up?

DSCN7042.JPG


Within in our .823 to .866. If I want to tighten it up further I could add a selective in the middle.... maybe I will.... maybe just enough to make the pack .845 or so - resulting in a final number in the middle range.

That will mean replacing a .069 Kolene with something closer to .089. I have one of those... So here is the final pack I selected - adding a selective to the middle of the clutch pack - measured. (and the steel is thicker so will behave better thermally)

DSCN7057.JPG

So if we assume the cavity of 2.500, subtract the clutch pack thickness of .853, we should come out around 1.647. Tending towards the closer tolerance in the FORD spec, and wider than ALTO suggests. I can live with this.


Next post... lets install and see what we get!
 






Well... I installed the plates and frictions... and measured...

DSCN7058.JPG


here is what came up

DSCN7059.JPG



then 180 degrees apart... measured again...

DSCN7061.JPG


and got

DSCN7060.JPG


and here is what I got. Somehow I'm picking up about an extra 0.010 from what my calculations tell me I should be getting... Now 1.636 is within specs, and preferred by ALTO...To me? This clearance is on the close side but acceptable.... yet I like a little more room than that to the close end of specs.... What to do? How about going to a smaller selective in the middle?

Ok, so I went from .089 to .079 and get...

DSCN7065.JPG


and 180 away

DSCN7066.JPG


Now this I can live with - as I said... about what I was looking for. call it done.

Here is the final appearance of the intermediate clutch, before the pump is installed...

DSCN7067.JPG


Intermediate clutch is DONE. Up next... pump prep and install.
 






One final caution. IF you bought a NEW pump, it will come with the intermediate piston.... BUT!!! That piston MAY or MAY NOT have seals on it. NEVER ASSUME in building Automatic trannies. CHECK, CHECK and RE-CHECK. It might just save you a major headache later.

Enough warning.

Ok, Pump Installation... part 14, continues here:

http://www.explorerforum.com/forums/showthread.php?t=160708
 






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