4R70W Rebuild Diary - Part 5 - Direct drum

[Glacier991]

The direct drum in the 4R70W sits inside the output shaft ring gear shell. In the AOD is was cast iron... and I was told by the time it went into the AODE and 4R70W it had migrated to stamped steel and then and back to cast by the time it got the the 4R70W. I could not verify the truth of this. In fact it looks to me like it went to stamped steel and stayed there.

Once again I had new and used to compare. My used were out of a good tranny and so not "used" as in... NOT from a fragged transmission.

So I have decided to go with stamped steel. I am not adverse to the idea.... just that cast iron sounds better <g>.

Here is the old and new... side by side

Here is the "old"

Here is the "new"

here there are snout to snout. Maybe you can see the slight wear marks on the old. I miked them.... same same. Some sandpaper and the old snout will be as good as the new - it rides in a bronze bushing:

Here is the back end.... where the input shaft goes.... old

and new

again same on measurement.... both will get scotchbrited.

The other place to check for damage is where the steels ride in the drum. We are looking for indents that will prevent the steels from riding up and down smoothly....

Old.... (it looks good)

and new...

The direct drum is FORD Part # F6AZ-7F283AA and lists for $56.23.
The direct drum piston is FORD part # F2VY-7A262-A and lists for #13.33
The direct drum retainer and springs are FORD part # E5AZ-7F235-A and lists for $5.35

FRICTIONS AND STEELS

This drum came in our situation with a count of 6. Alto makes two kits that add 2 to make it 8 that you can add without any changes or machining required. There are pros and cons to adding to the stock count using the ALTO setup.

Pro: You spread the holding load to more surface with extra steels and frictions. More equals better holding power. (regardless of whether it is ALTO or stock.)

Con: The ALTO frictions and steels are thinner and less able to dissipate the heat load - plus when not engaged they produce more heat due to friction. (Extra stock will do this too, but their thickness will dissapate the heat a little better.)

Which position is right or best? I dunno. My bigger concern is that the ALTO 8 friction setups (plural) have no grooves. Anyway... here is the stock friction/steel against the Alto first level upgrade:

[Note: These "used" frictions measured as perfect in terms of thickness as measured against new. My point being that properly cared for frictions last a LONG time. [I will be selling an entire rebuild kit out of the old transmission that tests out as good as new when I am all done here... cheap]

And here is the Alto first level against the HP (high performance) level with "kolene steels" - the black ones...

My choice? tough call. I wish I was custom building this for someone who KNEW what they wanted... but I am going with the HP series and Kolene steels.

[Note... this IS for sale on completion. Also see the end of this Direct Drum thread to see how to up the plate count using stock frictions]

Next the piston and assembly of the direct drum....meanwhile I need to soak the frictions in ATF for a while (I like to do it an hour or so but 15 mins is fine, enough to let them absorb all the ATF they can.)

 

[Glacier991]

Installing the piston, steels, frictions and retainer

We started with a naked new drum (the very thought is exciting, no?). The first step will be to add the piston. In the A4LD and 5R transmissions, the lip seals used on the piston are both installed on the piston. In this transmission's direct drum, one lip seal gets installed on the drum center "snout" and the other on the piston... something new for me. I was curious how difficult installing the inner seal would be without using a seal installer. So I put the seal on the drum snout and worked it down... and futzed with it for a few minutes without much success. (Seemed to be a little fear of damage situation... just frustrating)

Do I think you can put it on without the tool? Yes, but the tool makes it much easier... Here is the "tool"..

The tool slides down over the "snout"

You lube the tool and seal and slide the seal below the groove where it will ultimately reside in. Remove the tool and then slide the seal up and voila. MUCH easier. Easier to maintain the geometry of it all... that will sound wierd until you do it.

The other lip seal goes on the outer circumference of the piston. Take care to make sure the seals points DOWN into the drum (away from the spring posts when you put it on the piston). Installation of the piston may be able to be accomplished without a tool, but the risk of a damaged or turned seal is pretty high that way. The tool is safer and easier.
The piston is placed inside the seal tool

And ultimately the seal is compressed even with the edge of the piston

Put the entire assembly into a lubricated drum (vaseline is a good lubricant for this)... as deep as it will go...

Then using your fingers press the piston into place. It may take you a few tries, but it should not take a herculean affort to press it into place. When everything is good, it will go down in pretty easily. Here is the piston installed

The next step is to add the springs and retainer (they are unitized in this transmission as compared with some in other transmissions that you install one at a time) it goes onto the posts of the piston..

Then we need to use a compressor and compress the retainer so we can install the snap ring onto the snout that holds it all together

The snap ring is kinda bugger to get on as there is little room for the snap ring pliers. I found that of my two, one worked pretty well and the other did not. The tiny tips on the one set of pliers were a key for an easier installation.

Here is the snap ring installed:

And our direct drum is ready for frictions and steels.

We are going to use the Alto HP set with Kolene steels. We start with a steel (Kolenes come black as a result of the process that makes them "kolene")

then we add a friction,

.. and continue the process until all 8 frictions and the companion kolene steels are in, and then top the pack with a pressure plate.

next we add the snap ring retainer

And check the clearance

And voila... call it a clutch pack in a drum.

In the Alto upgrade, your clearance is set pretty close (.025 to .035). I assume this is because of the hydroplaning potential for the ungrooved plates. It is about half the usual setting for clutch pack clearances. I do know this is going to be a heat producer when not engaged. More and more I am an adherent of big coolers especially as we upgrade transmissions.

 

[Glacier991]

Once the direct drum is together.... now is the time to install the "hub". This is what engages the frictions and in effect connects them to the case of the planetary through a splined protruding "snout" on the end if the planetary.

Here is what I mean:

I have several hubs, including a new one. They all look more or less the same, though the edges on the "splinez" may be a little crisper in the new one. I have no heartbreak if you reuse the old one. New one is FORD part # EOAZ-F7236-B and lists for $10.25.

Before you install the hub there is a spacer and a torrington bearing. The spacer goes in with the machined side down into the drum (it's pretty intuitive) and the bearing goes in BLACK SIDE UP (important)!. THEN you can install the hub.

Here is how the hub should fit, all the way down into the splined frictions... and more or less flush with the top of the pressure plate

In the following pic, I have the new hub installed into the drum and frictions. To repeat: IT SHOULD SIT FLUSH with the top of the pressure plate. If not, it is not completely installed. This can be a little tricky. Just remember is WILL go flush. I am showing you a used hub with the installed one as a backdrop.

With the hub installed, the direct drum will be ready to install into the ring gear, with, of course, the proper torrington underneath it. Oh and, just as a reminder, he stub shaft will also get installed to connect the front clutch to the direct clutch. I put this here just as a reminder not to forget to install it at the proper time.

This shaft connects the direct drum and the forward drum so they spin together.

Next thread, BANDS

http://www.explorerforum.com/forums/showthread.php?t=157481

 

[Glacier991]

Alternate (Better?) Ways to Up the Direct Clutch Friction Count

You saw me use the ALTO thinner plate setup to raise the friction count from the stock max of 6 to 8. I expressed my thoughts on the heat that was going to produce and the thermal mass being smaller.... and cautioned to add a larger cooler.

Some well respected builders use this setup and swear by it. Others hate it and swear at it, claiming it burns up. So... how can you UP the count using stock frictions?

Well, there are two ways. First off.... remove the top pressure plate (last in)... and in it's place if it put one more friction and one more steel. Top that steel with the thinnest retaining snap ring FORD makes (P/N F3AZ-7D483A - .052 in thick - although you may be able to get proper clearance using other thicknesses, maybe) and you now have a 7 plate direct clutch. Relax, the thinner steel will do just fine in place of the thicker pressure plate. Oh, the P/N for the most current production friction plates is F8AZ-7B164-BA. They are black with radial grooves, not the waffle pattern any longer. These plates are supposed to be virtually indestructable.

Next, if you have access to a lathe, or a machine shop... take the piston out of the direct clutch and strip it down to bare. On the side facing up into the clutch, machine off .100 of material from that face. (Not any proprietary secret, just what it takes to get the clearance.) Then build it like we just did the 7 plate version, but this time, you will have room for 8 stock plates.

Cheaper than ALTO, and with fewer drawbacks. More difficult for the average Joe.

While we are here, let's talk about clearances in clutch packs. FORD specs are quoted in this article where they apply. General rule of thumb is that .005' is the close side per friction disc (eg. a 5 plate clutch would be tight at .025") and .010 is high (eg. a 5 plate clutch would be .050").

Jerry W. suggests when in doubt err on the high side - s'why I suggested the thinnest snap ring in the stock 7 plate setup - your results may vary, measure. The Snap rings for this drum are P/N F3AZ-7D483 A thru D.... 4 thicknesses A, B, C and D.

 

[Glacier991]

If you have questions, comments, ideas or just feel an overwhelming need to post about this thread, please go here ...

http://www.explorerforum.com/forums...ad.php?t=161450

I am trying to make it easy for folks just wanting basic information. The questions etc can have their own thread. Thanks for understanding.

 

[lupevega]

thanks for this

 

[The Electrician]

4R70W Rebuild Diary - Part 6 - Bands

http://www.explorerforum.com/forums/showthread.php?t=157481

 

[RebuildmyMuatang]

If you have questions, comments, ideas or just feel an overwhelming need to post about this thread, please go here ...

http://www.explorerforum.com/forums...ad.php?t=161450

I am trying to make it easy for folks just wanting basic information. The questions etc can have their own thread. Thanks for understanding.

Hey so I just finished putting together my direct clutch pack and the clearance below the snapping and the end plate is almost nothing at all can hardly get anything in there let alone the proper thickness feeler gauge. What did I do wrong I just replaced the seals and put new clutches in That’s it. Could I have used the wrong snap ring? Any ideas what I did wrong.

 

[CDW6212R]

Hey so I just finished putting together my direct clutch pack and the clearance below the snapping and the end plate is almost nothing at all can hardly get anything in there let alone the proper thickness feeler gauge. What did I do wrong I just replaced the seals and put new clutches in That’s it. Could I have used the wrong snap ring? Any ideas what I did wrong.

Welcome. There are several different snap rings made for each drum, different thicknesses. It is not uncommon to need a different snap ring when the frictions and steels are replaced. Measure the gap assembled, and aim for at least .010" for each friction in the drum. So for five clutches, it has to have at least .050" gap, a little more is ideal. I like to aim for close to .015" clearance(just under) per clutch(one friction and one steel). The different snap rings are IIRC about .065" between them, they vary. The direct drum snap rings are the smallest in the transmission, while the other drums use the same diameter snap rings.

So measure your snap ring, and see what the next thinner version costs. That might be the one you need.

 

[RebuildmyMuatang]

Welcome. There are several different snap rings made for each drum, different thicknesses. It is not uncommon to need a different snap rings when the frictions and steels are replaced. Measure the gap assembled, and aim for at least .010" for each friction in the drum. So for five clutches, it has to have at least .050" gap, a little more is ideal. I like to aim for close to .015" clearance(just under) per clutch(one friction and one steel). The different snap rings are IIRC about .065" between them, they vary. The direct drum snap rings are the smallest in the transmission, while the other drums use the same diameter snap rings.

So measure your snap ring, and see what the next thinner version costs. That might be the one you need.

Okay thank you

 

[transman304]

There are like 4 different thickness snap rings. I would double check the stack up as I don’t recall ever having problems achieving the proper clearance.
Brad

 

[JK080]

I agree, check your stack up I dont think I can remember having a clearance issues with this drum.

Look for clutches that might not be flat and compare the new clutches to the old ones if they are not destroyed.

 

[CDW6212R]

Very true, usually there is too much clearance for me, and I bought all of the snap rings to set the clearance I want.