Automatic Transmission Shutters at 45mph
Thread Starter
Racer
Joined: Sep 2006
Posts: 389
Likes: 1
From: Roswell GA
Automatic Transmission Shutters at 45mph
My wife's Tahoe had water come through the sunroof and caused numerous electric issues. (I know it is not a Corvette but is still in the GM family
) They all seem to be fixed now that it dried out and realigned the sunroof and sealed to keep water from getting in. The truck runs great except for when the car hits 45mp the transmission shutters. Once you get past 50-55 mph the car is fine again. All lower gears shift great. I found that the TCC should lock up at 45mph, could this be causing the shutter problem? No codes are being thrown right now.
Any advice?
Thanks,
Doug
) They all seem to be fixed now that it dried out and realigned the sunroof and sealed to keep water from getting in. The truck runs great except for when the car hits 45mp the transmission shutters. Once you get past 50-55 mph the car is fine again. All lower gears shift great. I found that the TCC should lock up at 45mph, could this be causing the shutter problem? No codes are being thrown right now.Any advice?
Thanks,
Doug
Thread Starter
Racer
Joined: Sep 2006
Posts: 389
Likes: 1
From: Roswell GA
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Le Mans Master
Joined: Dec 2006
Posts: 7,251
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From: Phoenix Arizona
and bad motor or tranny mount 
Burning Brakes
Joined: Aug 2000
Posts: 894
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From: Bethel Township Ohio
Tech Contributor
Joined: Jan 2007
Posts: 19,470
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From: Dyer, IN
Document ID# 10233
2004 Chevrolet Tahoe - 4WD
Torque Converter Clutch (TCC) Shudder
Checks
Causes
Electrical
* 12 volts not supplied to transmission
* Outside electrical connector damaged
* Inside electrical connector, wiring harness or solenoid damaged
* Electrical short (pinched solenoid wire)
Converter (1)
Internal damage
Oil Pump Assembly (4)
* Converter clutch valve stuck or assembled backwards
* Converter clutch valve retaining ring mispositioned
* Pump to case gasket mispositioned
* Orifice cup plug restricted or damaged
* Solenoid O-ring seal cut or damaged
* High or uneven bolt torque (pump body to cover)
Input Housing and Shaft (621)
* Turbine shaft O-ring seal cut or damaged
* Turbine shaft retainer and ball assembly restricted or damaged
Transmission Fluid Pressure Switch Assembly (69)
* Contamination
* Damaged seals
Control Valve Body Assembly (60)
* TCC signal valve stuck
* Solenoid O-ring leaking
Shift Solenoid Screen (367A/367B)Blocked
2004 Chevrolet Tahoe - 4WD
Torque Converter Clutch (TCC) Shudder
Checks
Causes
Electrical
* 12 volts not supplied to transmission
* Outside electrical connector damaged
* Inside electrical connector, wiring harness or solenoid damaged
* Electrical short (pinched solenoid wire)
Converter (1)
Internal damage
Oil Pump Assembly (4)
* Converter clutch valve stuck or assembled backwards
* Converter clutch valve retaining ring mispositioned
* Pump to case gasket mispositioned
* Orifice cup plug restricted or damaged
* Solenoid O-ring seal cut or damaged
* High or uneven bolt torque (pump body to cover)
Input Housing and Shaft (621)
* Turbine shaft O-ring seal cut or damaged
* Turbine shaft retainer and ball assembly restricted or damaged
Transmission Fluid Pressure Switch Assembly (69)
* Contamination
* Damaged seals
Control Valve Body Assembly (60)
* TCC signal valve stuck
* Solenoid O-ring leaking
Shift Solenoid Screen (367A/367B)Blocked
Drifting
Joined: Aug 2004
Posts: 1,799
Likes: 1
From: Dayton Ohio
Thread Starter
Racer
Joined: Sep 2006
Posts: 389
Likes: 1
From: Roswell GA
I confirmed that there was not a misfire and everything was running smooth. I gave up and took the Tahoe to the transmission shop. They said it was not an electronic problem and that it must be something internal. They thought it might be the tranmission pump that could not keep the line pressure high enough. They said they would have to take it out to confirm and at that point I might as well rebuild.
When the problem first started, it was several days in a row, then it became intermittent and now it has been gone for about 4 days. At this point, I am going to let it ride and see what happens.
When the problem first started, it was several days in a row, then it became intermittent and now it has been gone for about 4 days. At this point, I am going to let it ride and see what happens.
Burning Brakes
Joined: Nov 2002
Posts: 807
Likes: 21
From: Los Altos CA
Next, with the torque converter locked, give it a moderate amount of throttle. If the rpm goes up, then the TCC is slipping
Le Mans Master
Joined: May 2006
Posts: 7,875
Likes: 254
From: Hillsboro OR
Mine started doing this today. 
There are settings in the transmission tune that effect the TCC. I'm not expert enough to tell you where to set them or why. I just know the settings do exist. The following is what I have seen in a trans tune that was sent to me. I haven't programmed these yet but, they came from a respected trans tuner.
TCC Apply/Release Speed:
TCC Apply/Release Speed vs TPS vs Gear.
- Second gear apply/release numbers were all 256.
- Third and Fourth apply/release numbers were increased 40%.
- Everything beyond 75 mph was set to 256 also.
TCC Duty Cycle:
TCC DC Maximum vs. Line Pressure vs. Trans Temp.
- Set to 100 across the board.
TCC DC Minimum vs. Line Pressure vs. Trans Temp.
- Set to 90 across the board.
HTH.
There are settings in the transmission tune that effect the TCC. I'm not expert enough to tell you where to set them or why. I just know the settings do exist. The following is what I have seen in a trans tune that was sent to me. I haven't programmed these yet but, they came from a respected trans tuner. TCC Apply/Release Speed:
TCC Apply/Release Speed vs TPS vs Gear.
- Second gear apply/release numbers were all 256.
- Third and Fourth apply/release numbers were increased 40%.
- Everything beyond 75 mph was set to 256 also.
TCC Duty Cycle:
TCC DC Maximum vs. Line Pressure vs. Trans Temp.
- Set to 100 across the board.
TCC DC Minimum vs. Line Pressure vs. Trans Temp.
- Set to 90 across the board.
HTH.
