2000 Tahoe Z71 Noise coming from Torque Converter Area

[FreshBoxLive]

(241,000miles)
Just finally was able to track down the source of a clank metal fan type noise, as the noise has gone from a rare occasion, to a pretty consistant raquet. It sounds like its coming from the torque converter area, mostly under throttle but occasionally at idle. There are no effects on the drivability of the vehicle. I've attached a video as well. I have access to a shop and tools. I am a hydraulic mechanic, so any help would be awesome!

 

[bigfootchiro]

Sounds like a loose/broken flywheel

 

[willxfs]

Pull the dust cover off the bottom of the transmission and inspect the flywheel and torque converter bolts.

 

[swathdiver]

Check the torque converter bolts first, then the flywheel. Maybe the cats too? I suspect a bad torque converter itself but it does sounds kinda like loose bolts.

 

[FreshBoxLive]

Ok thank you guys. I will crawl under her either tomorrow or Friday. I will let y'all know what I find.

 

[Rocket Man]

The flywheel is actually called a flexplate on an automatic and that's what it sounds like to me. If you can't see good enough through the inspection plate pull the starter bolts and slide it forward or else remove it and you can see better. You can have someone turn the crank bolt with a breaker bar so you can see it rotate. It sounds like it's cracked and hitting something. Don't drive the truck because if it breaks completely it will cause more damage.

 

[bigfootchiro]

The flywheel is actually called a flexplate on an automatic.

That is what I meant. Thank you for correcting me!

 

[Cattivo]

I have a similar sound, only while accelerating...nothing while idling. I'm curious to see what you find...keep us posted brother

 

[JonnyTahoe]

The flywheel is actually called a flexplate on an automatic and that's what it sounds like to me. If you can't see good enough through the inspection plate pull the starter bolts and slide it forward or else remove it and you can see better. You can have someone turn the crank bolt with a breaker bar so you can see it rotate. It sounds like it's cracked and hitting something. Don't drive the truck because if it breaks completely it will cause more damage.

I had this happen to my 2000 Tahoe at about your exact mileage. It would make a Rattle every time I started the truck then it would also happen when the A/C was running so I took it to my local GM dealer and had them listen to it and the mechanic said it sounds like the Flex plate bolts are loose, ''We have seen them loosen up before''. I thought how could they loosen up when they are installed from the factory with Thread Locker? They were not !! Really. Jack your truck up really good and use many safety jacks, floor jacks, jack stands whatever, you are going to be way under the truck. You Cannot remove the starter without removing the dipstick tube but you can move it enough to access the bolts, They will be loose and there are only three of them. You will need an Allen Wrench or a Allen socket I just used a wrench. If I were to do the job again I would try to remove each bolt and put Thread Lock on them but it was hard enough just getting to them so I just tightened them up the best I could.

 

[JonnyTahoe]

Sounds like a loose/broken flywheel

And you would be correct.