UAE_Z28

iTrader: (14)

Hello,

I think I have a problem with my transmission. I'll be listing the symptoms hoping that someone would chime in.

Whenever I'm going around 20mph and press around halfway on the throttle, the car shakes a vibrates, the car vibrates and shudders, the rpm/speed do not increase unless step off a little bit off the throttle and press again.

When the torque converter is locked (around 50mph) and I press around a little more than halfway on the throttle(not to the point where the car would downshift) the car also vibrates, shudders and doesn't increase in speed or rpm.

At times on WOT the car accelerates normally, and sometimes it gets stuck around 2200~ rpm for a couple of seconds then sluggishly returns to normal behaviour and accelerates.

Sometimes these symptoms happen, sometimes they do not and the car behaves normally. I'm thinking that my T/C is about to fail.

I do change transmission oil + filter religiously and the oil looks fine.

Anyone has any idea what could be the reason?

FirstYrLS1Z

iTrader: (4)

Is the convertor the stock convertor or an replacement aftermarket convertor ?

UAE_Z28

iTrader: (14)

Its the stock converter.

shepss217

iTrader: (5)

Well now is the oportune time to upgrade that and your flexplate! WOA don't do the converter and not the flexplate, it will crack with higher stall speeds and torque. It's worth the $100 or so for an sfi approved flexplate

UAE_Z28

iTrader: (14)

Thank you for your reply, was thinking of doing that. I dont want to go replacing parts and ending up with the problem unsolved.

Any more opinions?

coryforsenate

iTrader: (1)

Have you checked line pressure? TC shudder can be caused by low line pressure. I'm assuming since you didn't mention any, there are no codes?

clinebarger

Misfire??

UAE_Z28

iTrader: (14)

There are no codes, I'll be checking the line pressure as well.

forcd ind

iTrader: (7)

Wondering if the conv. is not unlocking like it should, maybe a tune problem or Throttle position switch
What happens if you lay your foot on the brake pedal so it unlocks the conv., does it work better, RPM's go up

UAE_Z28

iTrader: (14)

The converter is locking/unlocking properly. Its just the shudder the car gets when its locked. Another issue I'm having is whenever I go heavy on the throttle, occasionally the car shudders at a certain rpm around 2.3k. If I reach that rpm going easy on the throttle no issues there.

ICRAZY6

iTrader: (68)

I've recently had similar issues with the wife's car. Under steady acceleration it would shudder around 25-30mph then again 55-60mph and it did it really bad when going up a hill. Went to a good GM dealership, since car still has a warranty, and come to find out it's the Torque converter. Replaced. No problems since.