Hi, this is my first post. I have a 2007 Tahoe 5.3 4x4 LT. At 48,000 miles I decided to change the transmission fluid and filter and add a tranny cooler because I tow a boat and the trans temp was getting up above 200. Everything went fine with the change and installation, but the next day while driving I began to notice a shudder at cruising speeds 55-70 under light acceleration almost exclusively as I begin up an incline. I have to think that it is related to the work I did, but not quite sure what could be causing. Anyone experienced anything similar? Any thoughts on what I should do? Any help would be appreciated. Thanks!

 

What kind of trans fluid did you use?

 

Did you remove the wheels to do the work? If so, lugs tight? Were the tires rotated to a different position when re-installing? Check the simple things first.

 

Was the correct filter used. I mean they need to look 100% the same. If not that is more than likely the problem. Also recheck the level of fluid the new cooler might have dropped the fluid down to low. I doubt it but worth a shot.

 

I used synthetic Dexron VI. I did not remove the tires. I originally thought it was a wheel balance issue, but I just had them balanced, and I did not rotate them. Also, the shudder is not in the steering wheel but right underneath the drivers seat and it only happens when holding steady speed and i start to head uphill slightly. It almost feels like the vehicle is lugging. Kind of like the feeling you get on a manual transmission when you don't push the clutch in till the last second before it wants to stall. I was so frustrated yesterday I dropped the pan again and checked the filter and the seal. They both look good. An exact match to the original. I talked to a mechanic online and he said it is possibly the torque converter clutch or i hit and cracked one of the solenoids in the pan. I did some research on the tcc and it sounds like my symptoms mimick the symptoms of a bad tcc. I'm far from a mechanic, so Im not really sure. I think I'm going to remove the trans cooler and take it to the dealer cause its still under warranty. Any thoughts? Thanks for the help!

 

I would suggest at this point to take the vehicle to the dealership seeing as it still should be well within the powertrain warranty at the least. They should be able to diagnose and take care of the problem as well.

Jeff Morris, Chevrolet Customer Service

 

So I removed the tranny cooler and the shudder went away.? I figured it must be the amount of fluid so I put it back on with less fluid and that seems to have fixed it. I guess the transmission is pretty sensitive to the amount of fluid. Seems like its good to go. Thanks for the help!

 

Glad you got it to work!