TCI 6X 6 Speed Automatic Autopsy...... - Chevelle Tech
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post #1 of 24 (permalink) Old Apr 3rd, 14, 12:50 PM Thread Starter
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TCI 6X 6 Speed Automatic Autopsy......

I made a post in the transmission section a few days ago stating I had hurt my TCI 6X.

The car is over at Carl's Transmission in Baytown, (very reputable), and they found that the direct pressure plate in the clutch basket shattered in about 8 pieces. The big question is why?

http://www.454ss.com/Articles_new/re...n_Problems.asp
In this link, part 617 is what shattered.

The sprague running surface on that basket is also scared, so we will replace that, along with the clutch pack.

The technicians opinion is that the Electronic Controle Pressure Solenoid stuck. The piece that broke does not directly transmitt power, it compresses the plates in the clutch basket.

I have talked with TCI. The man I need to talk to is Dennis Cambell, who is out of town at the moment. I am going to send them pictures, and box up the broke parts for their assessment.

Everything else in the unit looks good.

In the mean time, I told them to get the parts and get her back together. The broken pieces are all 4L80E parts, he said it will all be back together by next Wednesday.

I will see what TCI says. The unit is 9 months old, I would not expect a part such as this to fail, causing this type of problem. We will see.

'67 Chevelle Malibu, Catalina Blue, 540 inch Rat, Air Flow Reasearch 290 CNC Heads heads, Custom Hyd Roller, .675 lift, 234, 244 at .050, Lemons Headers, Holley Multiport Fuel Injection, TCI 6X 6Speed Automatic, 12 bolt Posi Eaton TruTrac, 3:31 Richmond Gears, front and rear power disc brakes, Global West Suspension, etc.

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post #2 of 24 (permalink) Old Apr 3rd, 14, 1:13 PM
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Gene
 
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Re: TCI 6X 6 Speed Automatic Autopsy......

That trans costs more than my engine and trans combined. Where you racing it hard? I would have thought it was as least as bulletproof as a T400.

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post #3 of 24 (permalink) Old Apr 3rd, 14, 2:12 PM Thread Starter
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Re: TCI 6X 6 Speed Automatic Autopsy......

Sure, I run it hard on the street, on street tires.

The parts that broke are not nessessarilly power transmitting parts, as far as radial load goes. That plate is the backing plate that the friction plates seat against as hydraulic pressure is applied too compress the friction discs.

Or at least I would think.

'67 Chevelle Malibu, Catalina Blue, 540 inch Rat, Air Flow Reasearch 290 CNC Heads heads, Custom Hyd Roller, .675 lift, 234, 244 at .050, Lemons Headers, Holley Multiport Fuel Injection, TCI 6X 6Speed Automatic, 12 bolt Posi Eaton TruTrac, 3:31 Richmond Gears, front and rear power disc brakes, Global West Suspension, etc.

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post #4 of 24 (permalink) Old Apr 3rd, 14, 2:41 PM
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Re: TCI 6X 6 Speed Automatic Autopsy......

Direct pressure plate isn't a common failure.
Could have possibly been overheated causing it to get brittle. Too much clutch pack clearance causing shock load on shift, or just a fluke failure.
post #5 of 24 (permalink) Old Apr 3rd, 14, 3:29 PM Thread Starter
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Re: TCI 6X 6 Speed Automatic Autopsy......

There is no indication of heat, burned fluid, or anything in the unit. Just broken pieces.

One thing that is strange, the big snap ring that keeps that plate in place was not distorted at all, nor the groove it fits in. You can still see the writing on most of the clutch pack friction plates.

Is that backing plate made from from iron? I should have brought a piece back to my shop and checked it.

'67 Chevelle Malibu, Catalina Blue, 540 inch Rat, Air Flow Reasearch 290 CNC Heads heads, Custom Hyd Roller, .675 lift, 234, 244 at .050, Lemons Headers, Holley Multiport Fuel Injection, TCI 6X 6Speed Automatic, 12 bolt Posi Eaton TruTrac, 3:31 Richmond Gears, front and rear power disc brakes, Global West Suspension, etc.

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post #6 of 24 (permalink) Old Apr 3rd, 14, 8:43 PM
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Re: TCI 6X 6 Speed Automatic Autopsy......

Yes it's iron.
post #7 of 24 (permalink) Old Apr 3rd, 14, 10:22 PM
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Re: TCI 6X 6 Speed Automatic Autopsy......

I would run a strait cut Turbo 400 with 2.56 gears before I would run any over drive automatic.

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post #8 of 24 (permalink) Old Apr 3rd, 14, 10:29 PM Thread Starter
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Re: TCI 6X 6 Speed Automatic Autopsy......

Quote:
Originally Posted by VORTECPRO View Post
I would run a strait cut Turbo 400 with 2.56 gears before I would run any over drive automatic.
Doesn't a turbo 400 have the exact same part in it, or something very similar?

'67 Chevelle Malibu, Catalina Blue, 540 inch Rat, Air Flow Reasearch 290 CNC Heads heads, Custom Hyd Roller, .675 lift, 234, 244 at .050, Lemons Headers, Holley Multiport Fuel Injection, TCI 6X 6Speed Automatic, 12 bolt Posi Eaton TruTrac, 3:31 Richmond Gears, front and rear power disc brakes, Global West Suspension, etc.

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post #9 of 24 (permalink) Old Apr 3rd, 14, 10:51 PM
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Re: TCI 6X 6 Speed Automatic Autopsy......

It probably does, but I have never hurt a Turbo 400 ever, its far lighter and probably faster despite the 2.56 gearing, and less headaches as well.

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post #10 of 24 (permalink) Old Apr 3rd, 14, 11:54 PM
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Re: TCI 6X 6 Speed Automatic Autopsy......

Quote:
Originally Posted by VORTECPRO View Post
It probably does, but I have never hurt a Turbo 400 ever, its far lighter and probably faster despite the 2.56 gearing, and less headaches as well.
Same part in a TH400.
We've had 4L80s go faster than 400s with the same converter stall speed, so definitely not necessarily slower.
I'm not a fan of the 6 speed version of the 4L80.

400s break all the time, and a 2.56 geared 400 combo will be slower than a properly geared 4L80, every time.

A 4L80 essentially is a TH400 with an internal OD unit added. We've used them successfully at over 1500 RWHP, multiple times.
We've had them survive when the Fab 9 rear diff was in pieces on the ground.
post #11 of 24 (permalink) Old Apr 4th, 14, 8:39 AM
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Re: TCI 6X 6 Speed Automatic Autopsy......

I hope TCI takes care of you on this. You would think it would live on the street with street tires. Any big burnouts while shifting, pretty sure that is what grenaded my TCI TH400 on the street.

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post #12 of 24 (permalink) Old Apr 4th, 14, 11:09 AM Thread Starter
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Re: TCI 6X 6 Speed Automatic Autopsy......

Quote:
Originally Posted by JBoggs View Post
I hope TCI takes care of you on this. You would think it would live on the street with street tires. Any big burnouts while shifting, pretty sure that is what grenaded my TCI TH400 on the street.
I doubt TCI is any under any obligation 9 months into an installation.

My concern is why a part that is generic to a Turbo 400, 4L80e, and this TCI 6x, would shatter like that. I can see gears busting, shafts twisting, torque converters grenading etc, under the load of a big street engine,but this is a part that is not part of the radial transmission of power. It is just a backing plate for the clutch frictions.

What is to keep it from doing it again?

Mr, Cambell, the warranty man at TCI, will not be in until Monday. So maybe then..........

'67 Chevelle Malibu, Catalina Blue, 540 inch Rat, Air Flow Reasearch 290 CNC Heads heads, Custom Hyd Roller, .675 lift, 234, 244 at .050, Lemons Headers, Holley Multiport Fuel Injection, TCI 6X 6Speed Automatic, 12 bolt Posi Eaton TruTrac, 3:31 Richmond Gears, front and rear power disc brakes, Global West Suspension, etc.

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Last edited by jackie schmidt; Apr 4th, 14 at 11:25 AM.
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post #13 of 24 (permalink) Old Apr 4th, 14, 12:10 PM
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Re: TCI 6X 6 Speed Automatic Autopsy......

Jackie, I am sure TCI will hold no obligation to you, but I would keep them informed of what is going on as far as the cause. This is the first time I have ever heard of a failure of those 6 speeds past install issues. It is sounding like a simple defective part failure, but who knows? Hopefully your builder can pinpoint the exact cause.

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post #14 of 24 (permalink) Old Apr 4th, 14, 10:23 PM
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Re: TCI 6X 6 Speed Automatic Autopsy......

Quote:
Originally Posted by jackie schmidt View Post
I doubt TCI is any under any obligation 9 months into an installation.

My concern is why a part that is generic to a Turbo 400, 4L80e, and this TCI 6x, would shatter like that. I can see gears busting, shafts twisting, torque converters grenading etc, under the load of a big street engine,but this is a part that is not part of the radial transmission of power. It is just a backing plate for the clutch frictions.

What is to keep it from doing it again?

Mr, Cambell, the warranty man at TCI, will not be in until Monday. So maybe then..........
That part is generic to a 400, 4L80E, and the TCI 6x. The TCI 6x is just a 4L80E that uses the OD portion on top of each gear to split the gears. There isn't anything internally different required than any other 4L80.
It is a modified valve body and a control system.

Just because that component doesn't have radial load doesn't mean it doesn't have load.
It is a pressure plate, similar to a pressure plate on a manual trans.
The direct clutch can see over 300 psi in reverse, multiply 300 psi by the area of the apply piston. Approx 5000 lbs of force as I recall. Leave the clutch pack clearance loose and you have a hydraulic battering ram.
post #15 of 24 (permalink) Old Apr 4th, 14, 11:38 PM Thread Starter
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Re: TCI 6X 6 Speed Automatic Autopsy......

Quote:
Originally Posted by jakeshoe View Post
That part is generic to a 400, 4L80E, and the TCI 6x. The TCI 6x is just a 4L80E that uses the OD portion on top of each gear to split the gears. There isn't anything internally different required than any other 4L80.
It is a modified valve body and a control system.

Just because that component doesn't have radial load doesn't mean it doesn't have load.
It is a pressure plate, similar to a pressure plate on a manual trans.
The direct clutch can see over 300 psi in reverse, multiply 300 psi by the area of the apply piston. Approx 5000 lbs of force as I recall. Leave the clutch pack clearance loose and you have a hydraulic battering ram.
That is the assessment of the technician at Carl's, or perhaps the high pressure solenoid stuck, causing way too much pressure and simply busting the cast iron plate.

In that case, the transmission could be behind a in line 6 cylinder and still break.

TCI does set these transmissions up with quite a bit of pressure, judging from the firmness of the shifts in high pressure mode. Is it too much for the components?......the shattered plate says probably if there was nothing amiss with anything else.

Anyway, hopefully I can talk to this Mr Cambell at TCI Monday, get a tech man at TCI to talk to Clint at Carl's and correct any problems to avoid any future problems related to this failure.

'67 Chevelle Malibu, Catalina Blue, 540 inch Rat, Air Flow Reasearch 290 CNC Heads heads, Custom Hyd Roller, .675 lift, 234, 244 at .050, Lemons Headers, Holley Multiport Fuel Injection, TCI 6X 6Speed Automatic, 12 bolt Posi Eaton TruTrac, 3:31 Richmond Gears, front and rear power disc brakes, Global West Suspension, etc.

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