corvettedoug

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

corvettedoug

Trying again....

HPS MASTER TECH

thats your converter trying to lockup

tlgarst

Don't know what year your Tahoe is but I have seen bad plug wire's do this. Yours may have coil packs if newer
Just a thought
TG

corvettedoug

So if it is the convertor trying to lock up, what would keep it from locking?

corvettedoug

It is an 04. I will check that as well. Besides at 45mph hour it runs perfect.

corvettedoug

bump up

corvettedoug

One more time. How could I test the TCC to see if it is fully engaging?

rustyguns

and bad motor or tranny mount

fastdriver1

Check for codes. That will be the start of finding the cause. That is a computer controlled transmission.

DALE C

Not enough line pressure at the valve I have seen it before. It will get worse, it can feel like you are driving on rumble strips

lucky131969

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

BanditDude

I had a misfire do the same thing on my older truck.

corvettedoug

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.

white90conv

First, when you think the torque converter is locked, give it a bit of throttle and tap the brake pedal. The rpm should go up noticeably.

Next, with the torque converter locked, give it a moderate amount of throttle. If the rpm goes up, then the TCC is slipping

Bluefire

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.