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Discussion Starter #1
Remember when I told y'all the transmission was acting up in the '95 Bird?

1st and 2nd worked fine, but when the car tried to shift into 3rd, it was like you hit the brakes. If I got going fast enough in 2nd, it would brake when going into 3rd, but then when it went into 4th it would take off.

Well, I put the 1997 transmission in out of the Sport I've been parting out and I just got a chance to pull apart the 1995 tranny that I suspected the roller clutch went bad.

Sure enough, this is what's left of the roller clutch I pulled out of the '95 tranny today:

 

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:eek:

It looks like the roller clutch snap ring came off..

The Sonnax Spiral Snap Ring prevents this sort of roller clutch failure..
Sonnax Spiral Snap Ring [Part #76554RK]

The Sonnax Spiral Snap Ring & 98+ Mechanical Diode would be a good upgrade for anyone considering rebuilding their AOD/4R70W..


Thanks for posting this..


Rayo..
 

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Discussion Starter #3 (Edited)
:eek:

It looks like the roller clutch snap ring came off..

The Sonnax Spiral Snap Ring prevents this sort of roller clutch failure..
Sonnax Spiral Snap Ring [Part #76554RK]

The Sonnax Spiral Snap Ring & 98+ Mechanical Diode would be a good upgrade for anyone considering rebuilding their AOD/4R70W..


Thanks for posting this..


Rayo..
No Rayo, the snap ring was on - I TOOK it off to survey the damage. I should have took more pics, but there were pieces of the roller clutch cage hanging out between the reverse drum and the clutch assembly. It was pretty ugly.

I'm not gonna rebuild this tranny because who knows how many little pieces are throughout the case - I found pieces in the pan when I pulled it.
 

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yummy! i got lucky and the TC seized up before i had any roller issues, though i was aware of them blowing quite often in taxi's and stuff.

i was planning on replacing mine with a 97+ anyway, when she finally locked up solid, put it any gear and it would act like you popped a manual clutch without throttle.... /die. had to neutral bomb her home, it was quite entertaining XD

was hoping to get a few more miles out of it, but she forced my hand :tongue: funny how that usually happens.

i also was not able to disassemble my old one... yard i got my MK8 one from wanted an intact core to rebuild. i suspect it was a TCC noid most likely. probably could have fixed the issue but the forward gears were slipping real bad anyway. that MK8 trans and the 11" TC it has woke my car up a surprising amount.
 

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NetKeym said:
the snap ring was on - I TOOK it off to survey the damage. I should have took more pics
Shoulda-Woulda-Coulda.. :tongue:

Since you don't have a clue why your Roller Clutch failed..Lets hope a real expert chimes in on what could have caused your Roller Clutch to fail like that..

:)



Rayo..
 

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1997 Thunderbird 4.6, 1998 Mark VIII LSC
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Common problem. Even though you could clean it out, that 95 case is total crap anyway.
What in particular causes the Roller Clutch to fail like this?..

Every case I ever heard of the Roller Clutch failing was due to the Snap/Retaining Ring coming off.. :confused:



Rayo..
 

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1994 Cougar XR7 DOHC/5-Speed
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What in particular causes the Roller Clutch to fail like this?..

Every case I ever heard of the Roller Clutch failing was due to the Snap/Retaining Ring coming off.. :confused:



Rayo..
The snap ring is the next weak link in the line after upgrading to a mechanical diode one way clutch(or getting a 98+ trans), the old roller clutch on the pre 98 4R70ws is generally the first to fail. Ford changed from the roller clutch to the mechanical diode because the roller is indeed so prone to failure.

If the snap ring is all you have heard of, you need to search and read up on the mechanical diode. There's several members here and elsewhere who have grenaded roller clutches
 

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Since you don't have a clue why your Roller Clutch failed..Lets hope a real expert chimes in on what could have caused your Roller Clutch to fail like that..
If you read the Transmissions 101 article, the Intermediate One way clutch is "Not suited for this environment".

Asking Why it failed is like asking why the 3.8's blow head gaskets .. a lot of contributing factors that exploit a design defect.
 

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Discussion Starter #11
If you read the Transmissions 101 article, the Intermediate One way clutch is "Not suited for this environment".

Asking Why it failed is like asking why the 3.8's blow head gaskets .. a lot of contributing factors that exploit a design defect.
How come this roller clutch is such an issue on these Ford overdrive transmissions? Don't other manufacturers use the same design one-way clutch in their transmissions? How comes theirs don't fail?

Oh, and BTW, that snap ring - when I pulled it off with a pair of snap ring pliers, one side came off pretty easily, but the other half was in there good and I had a hard time getting that sucker out of there!
 

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What in particular causes the Roller Clutch to fail like this?..

Every case I ever heard of the Roller Clutch failing was due to the Snap/Retaining Ring coming off.. :confused:



Rayo..
No, That's not what I did to my clutch either; my clutch failed like NetKeym's.

It's either the 2-1 or 3-2 that spins it like a b*tch and makes this really interesting squealing sound. :) Like a pig, or something. :D

It always happened to me at a downshift under power...

I spun both the clutch, and the two pieces of the driveshaft. :)

This doesn't always kill the tranny instantly.

That entrance ramp is so much smoother now...
 

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Discussion Starter #13
No, That's not what I did to my clutch either; my clutch failed like NetKeym's.

It's either the 2-1 or 3-2 that spins it like a b*tch and makes this really interesting squealing sound. :) Like a pig, or something. :D

It always happened to me at a downshift under power...

I spun both the clutch, and the two pieces of the driveshaft. :)

This doesn't always kill the tranny instantly.

That entrance ramp is so much smoother now...
I hardly ever do 2-1 downshifts because it's awful hard on it! I bet it was a 4-2 or 3-2 downshift because I noticed on these older trannys, when you floor it in 4th sometimes the engine speed climbs to 5-6K then all of a sudden 2nd gear hits (squeels the tires even). I bet that's what happened - what do you think, Grog?

Also, like you said, it didn't happen right away - we had just gotten back from Alabama with the Thunderbird and was almost home (driving easy the whole way). When I left a red light, that's when it didn't want to shift into 3rd. THAT'S when I first noticed the problem.
 

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Roller Clutch Failure

Aside from the Roller Clutch failing because someone was shifting at 6000+ RPMs..Which in turn causes the Snap/Retainer Ring to fly off..

This is another reason why the Roller Clutch would fail..Probably the reason yours failed Rick..

From: "The Man"..

Jerry Wroblewski said:
I don't know if I posted this on this board or not, but hear goes.

Unless you have the right hardware/chip, I would not drivearound in OD Cancel mode. Here is why.

First off, and most important, is the "dreaded shudder". In short, the shudder is caused by a breakdown between the oil/friction interface in the converter clutch. No matter what they claim, no shift kit can fix this, just give you harsh lockups. The converter clutch friction builds up alot of heat in 3rd gear for this reason. The converter clutch in the AODE/4R70W can be calibrated to slip at steady state in different gears. On the Marks it slips in 2nd and 3rd gear. Now think about this, you have enough apply force to hold 200 ft-lbs of torque pushing on the lockup plate, but it is slipping 20-50 rpm. Think of the heat that generates. This is the heat that causes shudder. Now you guys with 97/98 Marks have a much better calibration for this than the 96 and older guys, but the newer ones still slip, just a smaller window. When you drive around in OD Cancel mode, you are constantly slipping the torque converter clutch making heat. Heat is bad. A chip can remove the slip from the slip tables and eliminate this amount of heat build up.

The other reason is for you guys with roller ONE WAY CLUTCHES. The intermediate one way overruns, spins, in 3rd gear. The easiest way to hurt a one way clutch is to go from overrunning to locked, or a 3-2 shift. A high speed 3-2 downshift can hurt, of fail, a fragile one way clutch. You are less likely to do 3-2's if you are in 4th gear.

jerry
:thumbsup:


Rayo..
 

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How come this roller clutch is such an issue on these Ford overdrive transmissions? Don't other manufacturers use the same design one-way clutch in their transmissions? How comes theirs don't fail?

Oh, and BTW, that snap ring - when I pulled it off with a pair of snap ring pliers, one side came off pretty easily, but the other half was in there good and I had a hard time getting that sucker out of there!
The Intermediate One way clutch is overrunning in all gears except 2nd it locks. So you go from spinning to Locked on a 1-2 upshift, and a 3-2 downshift. In Manual 2nd and 4th gear, the OD band is applied so this holds the reverse drum, so the one way clutch is applied ( holding ) but ineffective, the OD band is doing most of the holding.

The problem with 3-2 downshifts is the additional stress on the drivetrain, normally when you are driving the power flow is transmitted from the engine to the rear wheels, but when you downshift the rear wheels can be the driving force working against the transmission internals even further.

On an application like the 4L60E/700R4 GM transmission for example the Forward sprag assembly ( one way clutch ) is holding in all gears except for 4th. So it goes from holding in 1-3 to overrunning which is an easy transition .. it only needs to go from overrunning to holding on a 4-3 downshift.
 

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Thanks, Rayo, nice post.

I can totally believe it; looking at the velocities involved, there's no way it was a 2-1. :)

When I upgraded the 96 Black Cougar's still working tranny, TC, and driveshaft, the PI intake and tune I had done to the car had completely wasted the 96 tranny, TC, and driveshaft.

The one way clutch came out in pieces, but was still hooking up somehow; it had issues, but not like you would think, looking like that, lol.

I upgraded to a PST aluminum DS, DirtyDog TC, and an 02 tranny, jmoded.

I'm having no issues at all now.


So, is the chance of failing a later model 4R70W higher doing a 3-2, or a 3-4 wot? :zdevil: There's a difference in the 3-4 shift in the later trannys...

My big problem is:

The 3-2 happens when you dramatically increase throttle; the 3-4 when you start to decrease throttle, without the "OD cancel" function engaged. It's a lighter shift that full WOT, but it's still pretty high.

Enquiring minds want to know, 'cause I'll likely be doing one of those two things, every work day, for the next 10 years at least, in the same place, merging with the same traffic. :cool: (In an MN12, god willing.)

Legal is 55 mph; it's never moving at that. :) It's not quite "merge properly or die" but it's close. ;)

I've never slipped one of the new ones like I did the old tranny, despite having much more power.
 

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'chuckle' yeah, i wanted something i could swap in without repinning or playing around with output shafts. i needed my car out on the road quick to get to college.

on the plus side that Mk8 trans had the mechanical diodes since i had to go inside and retrieve a check-ball from the main body.

during removal of the valvebody for the Jmod i dropped it a bit and lost the check-balls down in the case side valve-body. found all of them but one, which made its way down in-between the drums so i had to lift most of the guts out to find it :facepalm:
 

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Discussion Starter #18
Thanks, Rayo, nice post.

I can totally believe it; looking at the velocities involved, there's no way it was a 2-1. :)

When I upgraded the 96 Black Cougar's still working tranny, TC, and driveshaft, the PI intake and tune I had done to the car had completely wasted the 96 tranny, TC, and driveshaft.

The one way clutch came out in pieces, but was still hooking up somehow; it had issues, but not like you would think, looking like that, lol.

I upgraded to a PST aluminum DS, DirtyDog TC, and an 02 tranny, jmoded.

I'm having no issues at all now.

So, is the chance of failing a later model 4R70W higher doing a 3-2, or a 3-4 wot? :zdevil: There's a difference in the 3-4 shift in the later trannys...

My big problem is:

The 3-2 happens when you dramatically increase throttle; the 3-4 when you start to decrease throttle, without the "OD cancel" function engaged. It's a lighter shift that full WOT, but it's still pretty high.

Enquiring minds want to know, 'cause I'll likely be doing one of those two things, every work day, for the next 10 years at least, in the same place, merging with the same traffic. :cool: (In an MN12, god willing.)

Legal is 55 mph; it's never moving at that. :) It's not quite "merge properly or die" but it's close. ;)

I've never slipped one of the new ones like I did the old tranny, despite having much more power.
I never drive around with the O/D off - I live in the middle of nowhere so why would I need to? And since I live in BFE, I also have no reason to merge with traffic - because there isn't any ;)

However, since the later transmissions have made leaps and bounds improvements in this area - I'm just gonna grab one next time I have a problem. Trust me - I've been going through my head whether I should just do a quick j-mod or put this 2004 valve body in my 95 LSC (then should I get the mechanical diode - I know where I can get one for $50).

Decisions, decisions..... :rolleyes:
 

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Snap Ring has nothing to do with it.... Oh the humanity...

 

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Snap Ring has nothing to do with it.... Oh the humanity...
That looks familiar, lol. :thumbsup:

That's exactly how mine was when I disassembled it.

I drove it home ~50 miles; it wasn't wanting to shift, but it would. :facepalm:

The fluid was boiling when I pulled in the driveway, and was still too hot to touch the following morning, when we started taking it out. :rofl:


I fully expected to give it a ride home on a flatbed, but it wasn't having any of that. :) That's the same car I drove home with a bent valve another time, lol.

:D
 
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