2007 Chevy Suburban Transmission Shudder or Vibration

[silver911]

I have a 2007 Chevy Suburban with approx 45,000 miles. The transmission seems to shudder when driving on the highway in top gear. It almost feels like your driving over a rough bumpy road but when I put it in neutral or downshift into 3rd gear it goes away. So it's definitely not the road but the car. It only vibrates in 4th gear under load. If I feel it starting to shudder I can slightly reduce the throttle and it goes away. If I change to 3rd gear it also goes away. If I progressively add throttle it'll still shudder but then under enough load or kickdown it'll go away. All transmission fluid and diff/transfer case oils have been replaced. Any Ideas?

Thanks

[GMMerlin]

Originally Posted by silver911

I have a 2007 Chevy Suburban with approx 45,000 miles. The transmission seems to shudder when driving on the highway in top gear. It almost feels like your driving over a rough bumpy road but when I put it in neutral or downshift into 3rd gear it goes away. So it's definitely not the road but the car. It only vibrates in 4th gear under load. If I feel it starting to shudder I can slightly reduce the throttle and it goes away. If I change to 3rd gear it also goes away. If I progressively add throttle it'll still shudder but then under enough load or kickdown it'll go away. All transmission fluid and diff/transfer case oils have been replaced. Any Ideas?

Thanks

Might not be your transmission at all, you may have an engine misfire.
I would check plugs and wires, fuel injectors...

[silver911]

I've been meaning to replace those items anyways. I'll change and update with the results.

Thanks

[silver911]

OK
I just replaced the plugs and wires with new Bosch parts. It runs fine like before, it just shudders under certain partial load situations. Any other ideas?

Thanks,

Rich

[laxman21]

Originally Posted by silver911

OK
I just replaced the plugs and wires with new Bosch parts. It runs fine like before, it just shudders under certain partial load situations. Any other ideas?

Thanks,

Rich

Cap and rotor?

[silver911]

We'll, I took it to a local transmission shop. They spent a while road testing it before they could feel the shudder. The mechanic came back and said it definitely feels like a transmission issue. They did a bunch of test on it and couldn't find the cause of the shudder. Their last resort was to do a fluid & filter change and also add an anti-shudder additive. They said it might help. It looks like that did the trick. I've used it for a few days now and no sign of the shudder. I'm hoping that this takes care of it. The mechanic said the pan was very clean when he removed it so he's fairly confident that something isn't worn or broken in there. I just wanted to post the solution in case someone else has the same problem.

[Drineheart]

My 2005 Sub. 1500 had the same problem that occurred at 113,000 miles. Changed fluid and filter. Fixed it for a while but the problem is back. Was in a lot of rain the first time the problem appeared. Drove through lots of water in flooded area and the problem is back.

[randynight]

I had a '94 Sub that done the same. Done a transmission flush and fill with thier additive and after several doses of Lucas in the tranny it went away. I assumed it was a vibration right before or after the torque converter locks up? Try driving a steady speed and when it starts lightly touch the brake pedal to disconnect the converter lockup. On mine the shudder would immediately stop.

Bought a new Sub in '02 and it had a bit of the same problem, but a shot of Lucas made it go away.

[silver911]

We'll the anti-shudder additive worked for a little while but the shudder did come back. The guy at the transmission shop did tell me that my car probably still was covered under GM's 5 year/100,000 powertrain warranty. I finally had a chance to drop it off at the local Chevy dealer to see what they thought. The service manager agreed that something wasn't right. It's currently still in the shop. They initially thought that the solenoid that controls the torque convertor was bad, but that wasn't it. Now they've pulled the transmission and are replacing the torque convertor. I'll post the final results when I get the Suburban back. I thought I'd update the post in case someone else out there is having similar problems.

[silver911]

Got it back and the shudder is gone. We've driven it for a couple of days without a problem. Hopefully this is the last of the problem. Interestingly the dealer told be that the torque converter was replaced at 29k miles by the previous owner under warranty. Here i am w/ 56K miles and doing the same thing. Doesn't sound very reliable to me.