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Discussion Starter #1 (Edited)
I've recently broken the tranny in my tbird; it's an 02 4r70w from a gran marquis, and has about 55k miles on it.

I jmodded it when I put it in, about 6 months ago.

At the point it failed, it upshifted to 4th, then immediately downshifted.

It was at light throttle settings when it upshifted; I was nearing the end of the run. (2 mile long airstrip...)

Fluid was warm, about 210 degrees.


I'm reasonable sure I toasted the direct clutch; I'm hoping to drop the pan this weekend and see how bad it is.

It will drive some in 3rd and 4th; but it slips. I have not driven it other than to confirm it, and datalog the problem.


I have some questions:

There's nothing dark in the fluid; if the pan isn't full of garbage, do I have to replace the new torque converter?

Has anyone used the Raybestos Blue race frictions in one of these yet? Or is that a poor choice?

Any suggestions from the tranny gurus?

Are there any failures that might not be the direct clutch that could cause this? I'm going to look at the 2-3 acc before I pull the whole tranny.

Was this caused by my tune? I've heard something about a 127mph downshift issue... but of course, I cant find the post.


Any useful suggestions are greatly appreciated. :D

EDIT: SOLVED!!!!

This was a dented separator plate, and required mod parts. See below.

If you catch it before it kills the direct clutch, all you have to do to fix it is drop the pan and valve body, and repair/upgrade it.

EDIT #2: Not solved after all. :(

See below...
 

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Grog6 said:
I've recently broken the tranny in my tbird; it's an 02 4r70w from a gran marquis, and has about 55k miles on it.

I'm going to look at the 2-3 acc before I pull the whole tranny.
That would of been my first suggestion..Is to check the 2-3 accumulator, and make sure you're using the rubber bonded unit..

A bad 2-3 accumulator valve has been known to take out a direct clutch or 2.. :eek:

If the accumulator checks out..I would make sure the valve body gets thoroughly cleaned..

Also check all the valves, and check balls to make sure everything moves freely in the valve body..

Grog6 said:
There's nothing dark in the fluid; if the pan isn't full of garbage, do I have to replace the new torque converter?
If you plan on rebuilding this transmission..

You might as well shoot Alan an email, and ask him what the cost is to give your new torque converter a thorough inspection..

Before you reinstall it in your freshly built transmission..


Hopefully one of our transmission gurus chimes in.. ;)

Good Luck!



Rayo..
 

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Discussion Starter #3
If the accumulator checks out..I would make sure the valve body gets thoroughly cleaned..
...

You might as well shoot Alan an email, and ask him what the cost is to give your new torque converter a thorough inspection..
...

Hopefully one of our transmission gurus chimes in.. ;)

Good Luck!

Rayo..

I plan to disassemble the transmission thoroughly to clean and rebuild it, unless I find a simple reason for it slipping, and no major damage. I've been extremely careful with it since the problem; the plates may not be too bad yet.

That outcome is highly unlikely to be the case, lol.

I fully expect to find a handful of garbage laying in the bottom of the pan, doing a full tranny rebuild, and having to ship the TC back to Alan to get it properly cleaned; But there always misguided hope, right?

Anyone know anything about the Raybestos Blue plates?
 

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Anyone know anything about the Raybestos Blue plates?
AFAIK..The "Blue Plate Specials" are not recommended for daily drivers with low hp..


Again..I'm sure our resident tranny gurus will chime in, and correct me if I'm wrong..lol




Rayo..
 

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Discussion Starter #5
Dropped the pan and valvebody over the weekend; the pan is full of black goo, and the magnet is covered.

http://forums.tccoa.com/vbpicgallery.php?do=view&g=408

But, there are no chunks of metal, or burnt smell.

The 2-3 accumulator was in it's bore, pushed to the very bottom. It may have been out of the inner bore; I'm going to try the Fairbanks 2-3 accumulator piston, and see if it helps.

Anyone see a problem in using cheap fluid to test operation with? I hate to use expensive fluid for a test; if it works, I'll drain it and replace it with mercon V...

Also adding an inline filter. :thumbsup:

I'm sure I'll have to drop this tranny, but I wanted to try something else first, lol.

I don't think it can get broker... :)
 

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Discussion Starter #7
I bought the fairbanks kit with the 'special' 2-3 accumulator to see if it will make my direct clutch hook up.

The fairbanks kit looks good, and has some nice upgrades... IDK about removing checkballs; I need to read up on what that does, exactly. :)

If it works, I'll drain and reflush everything, and refill with Mercon V.

There's a lot of friction material in the pan, IDK if it will help of not; but it's a lot easier to drop the pan than the tranny. :)

I'm going to disassemble the valve body tonight, and clean it out.
 

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Those really are 1 time use.
 

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Discussion Starter #11 (Edited)
I bought a set the first time I did a jmod; they're 3 to a bag. :) I still have 2 of each.

Why are they different, top and bottom? I'd think they would be the same... :confused:


Here's a link to the datalog I did to confirm the problem.



56k go home, lol.


GM, have I misdiagnosed this, and the real issue is staring me in the face? Or did I not datalog a crucial item?
 

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Discussion Starter #12
Interesting find; I know why it slips, I know why it went south all at once.

:)

I don't know what caused the downshift, but dang, man...







Wow. :)

Any guesses how much pressure it takes to slam the accumulator that hard?

The point of the retainer went >1/8" deep, lol.

I'm going to assume the 2-3 piston came out of the bore; if so, do I even bother with putting a new separator plate and accumulator piston in it?

It likely has scrubbed most of the friction material off due to the leakage in the VB... Anyone know which passages those are?


On the good side, as I've never seen this breakage, not find pix of same on the intarweb; I hearby claim this as the Official Grog Mod. :rofl:

.Fix, Break, Repeat... :facepalm:

I'm gonna go work on the PI swap car. :)
 

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Without the stiffener disc like the older 4r70ws, I wouldn't retain the stock plate, I would get one of the thicker ones. That shows something to the extreme but I think in normal use there is is enough deflection to cause crosstalk between passages.
 

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Discussion Starter #14 (Edited)
Without the stiffener disc like the older 4r70ws, I wouldn't retain the stock plate, I would get one of the thicker ones. That shows something to the extreme but I think in normal use there is is enough deflection to cause crosstalk between passages.
+1. I agree; I'm going with both solutions.

This plate is "Deflected", lol. WTF caused the "blow out"?

I have to buy a plate, so the stiffener is a no-brainer. Sonnax has those fairly cheap.

If I can get all the crap flushed out of this tranny, it may still have some life left. Probably not. But worth ~$150 to try to fix.

At least it's not full of gritty black stuff... :)


Anyone have an idea why the piston would get slammed in the bore like that? Was it the 4-3-4 shift that happened?
 

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I'm no transmission expert, but my advice is:

Buy a Brand New seperator plate..
Buy a Brand New 2-3 Accumulator Piston (Bonded Rubber), and 2-3 Spring..
Buy a Brand New (2001-Up) 2-3 Accumulator Cover..

Check your valve body with a straight edge..So you know it's not warped..

Install your new seperator plate/gasket..Don't J-mod your new seperator plate..

Install your new 2-3 Accumulator Piston (Bonded Rubber), and 2-3 Spring..

If possible..Set the Transmission settings through your tune back to stock..

Then once you get everything back together..Cross your fingers, and hope you still have clutch material left on your Direct Clutch Frictions..
Grog6 said:
Anyone have an idea why the piston would get slammed in the bore like that? Was it the 4-3-4 shift that happened?
My guess is your line pressure was too high with the modifications you made to the seperator plate, and possibly the "Trans Tune".. :zdunno:



Rayo..
 

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Discussion Starter #16
Buy a Brand New seperator plate..

Check your valve body with a straight edge..So you know it's not warped..

If possible..Set the Transmission settings through your tune back to stock..

Then once you get everything back together..Cross your fingers, and hope you still have clutch material left on your Direct Clutch Frictions..

My guess is your line pressure was too high with the modifications you made to the seperator plate, and possibly the "Trans Tune".. :zdunno:

Rayo..

I have the stock plate; I plan to mod it to the Fairbanks settings, which are slightly different than the jmod settings. There are other differences as well.

The valve body worries me; I'm going to check it tomorrow with the laser and see if there's a circle stamped in the aluminum. I know how to do that one...

If so, I'm pulling the tranny immediately; I'm not going to dink with partial fixes at that point. I have a working spare tranny.

I didn't expect to see a freaking "mushroom stamp" on my @#@ separator plate, lol. :facepalm:

If it bent the steel plate bolted to the aluminum into a fairly sharp line, what did it do to the aluminum underneath?

That's for tomorrow; I'll have to set it up pretty carefully to get a good pic. :)

Can you use a 96 valvebody in an 02 tranny? I've read yes, but there are limitations...
 

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I didn't expect to see a freaking "mushroom stamp" on my @#@ separator plate, lol. :facepalm:

If it bent the steel plate bolted to the aluminum into a fairly sharp line, what did it do to the aluminum underneath?
If you think it might be helpful later, PATC has a thicker separator plate available. It's #8SP "Super Tough Plate"
 

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Discussion Starter #18

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Grog6 - if you come down to pick it up in person, let me know - I'll take you to lunch!

(I live about 5 miles from their office, but am not affiliated with them in any way.)

RwP
 

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Discussion Starter #20 (Edited)
Grog6 - if you come down to pick it up in person, let me know - I'll take you to lunch!

(I live about 5 miles from their office, but am not affiliated with them in any way.)

RwP
I'd love to; it's been years since I've had good food. :)

I won't be traveling, tho; too much to do, never enough time...

Ordered the parts today; thick plate and reinforcement plate. Hopefully here by the weekend. :)

Unless I wore off all the friction material, It should still work. (fingers crossed)

I think I'll get another 02 tranny and rebuild it as a 'full up' spare. Unless I end up pulling this one.

Man; we've pissed off all the tranny gurus here... Guess I'm going to have to learn a new field, lol.
 
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