vonrottes Posted March 24, 2019 Report Share Posted March 24, 2019 Got the hard shifting issues fixed, ended up being MY fault for using higher than stock shift pressure with an HD2 kit. saw something about it in a forum while looking up a pending code. But not I've got a much more troubling issue.. Clattering/knocking What I originally thought was just lifter noise has turned into more of a clatter than a knock yesterday. goes away around 1,500-2,000rpm in neutral gets worse in gear and when you run it up in gear holding the brake. and the newest most bothersome noise... Between shifts and on decel when the TC is locked it sounds like a jake brake.. If I apply the brake enough to unlock the TC and decel there is no weird noise.. I'm leaning towards a cracked flexplate, but considering it may be an issue with the torque converter itself. I tried to visually inspect it through the holes in the bellhousing but could not see any cracks but was very limited in what I could actually see. Checked the TC bolts and they are all tight, also used a large screwdriver to gently pry against the flexplate couldn't hear any creaking which is why I'm also considering the TC. Just wanted to see if anyone else has had an issue like this before I go and pull the transmission out.. Transmission is a 4l60e out of a 2000 Silverado 1500. flexplate and torque converter are from the same truck. Quote Link to comment Share on other sites More sharing options...
STEVE-O Posted March 25, 2019 Report Share Posted March 25, 2019 Sounds like you are going to be pulling the trans , and if I went to all that trouble I would rebuild it and get a new tq anyway so you never have to worry again ... hopefully Quote Link to comment Share on other sites More sharing options...
vonrottes Posted March 25, 2019 Author Report Share Posted March 25, 2019 Update trying to diagnose before pulling it apart. With the rear off the ground idling command a TCC lock it knocks, if I set absolute FC currant to say 800mv it does not knock idling in gear no load, but any throttle input it knocks. While driving TCC locks like it should with less than 2rpm slip So I am assuming this is an issue in the torque converter? Quote Link to comment Share on other sites More sharing options...
Cordell Posted March 25, 2019 Report Share Posted March 25, 2019 Never heard a torque converter make noise that wasn’t physically broken, usually a flexplate issue. Without experiencing that one I’m not sure I have any good advice for you. Did have this noise you thought was lifters ever since install and it got worse, or did it operate normally for awhile? Sure sounds more like something is loose. I wouldn’t be surprised if the flexplate is broken around the middle, you’ll never see that until the trans is out. Quote Link to comment Share on other sites More sharing options...
vonrottes Posted March 25, 2019 Author Report Share Posted March 25, 2019 The sound stayed pretty consistent until Saturday when it started this. Either way trans needs to come out, so Im just going to put a stock torque converter in it for now and a new flexplate while it out. Hopefully that fixes it. Finding info on failing torque converters is a pita most people just say it's a flexplate, which I'm not doubting. But the fact I can make the knocking stop by increasing the line pressure is weird...unless it's the transmission itself Quote Link to comment Share on other sites More sharing options...
zeitgeist57 Posted March 25, 2019 Report Share Posted March 25, 2019 Following this thread... My 2001 Silverado 4.3L/4L60E with 83k miles has the same rattle. Sometimes it's there, sometimes not...once it gets to about 2200+rpms it totally goes away. Definitely sounds like something in the bellhousing area, checked the Tq converter bolts to flywheel and they were strong. With engine running and I'm looking in the inspection port on the bellhousing there doesn't seem to be any problem with wobble. Driveability is good (and has been for the last 4k miles I've driven since last January - nothing's gotten louder or worse) but it sounds like it's tumbling rocks at times when driving. Shifts fine. I fixed the orange "Tow/Haul" mode button and the trans works even better. Sounds like something's loose. I'm remembering that GM flexplates are made out of cereal-box cardboard, so maybe Cordell's right about the center of the flexplate...daddy doesn't want to pull the transmission doe. Quote Link to comment Share on other sites More sharing options...
vonrottes Posted March 25, 2019 Author Report Share Posted March 25, 2019 Following this thread... My 2001 Silverado 4.3L/4L60E with 83k miles has the same rattle. Sometimes it's there, sometimes not...once it gets to about 2200+rpms it totally goes away. Definitely sounds like something in the bellhousing area, checked the Tq converter bolts to flywheel and they were strong. With engine running and I'm looking in the inspection port on the bellhousing there doesn't seem to be any problem with wobble. Driveability is good (and has been for the last 4k miles I've driven since last January - nothing's gotten louder or worse) but it sounds like it's tumbling rocks at times when driving. Shifts fine. I fixed the orange "Tow/Haul" mode button and the trans works even better. Sounds like something's loose. I'm remembering that GM flexplates are made out of cereal-box cardboard, so maybe Cordell's right about the center of the flexplate...daddy doesn't want to pull the transmission doe. That's how mine started. not sure how many miles I put on it since I got the engine back in. but it went from just an annoying sound at idle, which some people tried to tell me was a crank bearing or piston slap and what I just thought was shitty lifters on #8 Then it started this shit after some....Aggressive driving on Saturday.. I'll update the thread either tomorrow or Wednesday when I get the transmission separated from the engine. Hopefully the cause will be pretty obvious when I get it pulled apart. Quote Link to comment Share on other sites More sharing options...
cdk 4219 Posted March 25, 2019 Report Share Posted March 25, 2019 That's how mine started. not sure how many miles I put on it since I got the engine back in. but it went from just an annoying sound at idle, which some people tried to tell me was a crank bearing or piston slap and what I just thought was shitty lifters on #8 Then it started this shit after some....Aggressive driving on Saturday.. I'll update the thread either tomorrow or Wednesday when I get the transmission separated from the engine. Hopefully the cause will be pretty obvious when I get it pulled apart. More than likely the flexplate Quote Link to comment Share on other sites More sharing options...
Geeto67 Posted March 25, 2019 Report Share Posted March 25, 2019 have you thought about manual swapping it? Quote Link to comment Share on other sites More sharing options...
vonrottes Posted March 27, 2019 Author Report Share Posted March 27, 2019 Well got the new flexplate and torque converter in. Old one was not cracked but visibly warped. Just finished it up and started it, engine is quieter and runs smoother than it ever has. Quote Link to comment Share on other sites More sharing options...
zeitgeist57 Posted March 27, 2019 Report Share Posted March 27, 2019 So, do you think it was the torque converter as well, or just a damaged Flexplate? Thanks for the update. I busted my knuckles dropping a 29-gal gas tank to swap out fuel filters but the bellhousing rattle is on the list as well. Quote Link to comment Share on other sites More sharing options...
vonrottes Posted March 27, 2019 Author Report Share Posted March 27, 2019 So, do you think it was the torque converter as well, or just a damaged Flexplate? Thanks for the update. I busted my knuckles dropping a 29-gal gas tank to swap out fuel filters but the bellhousing rattle is on the list as well. I'm thinking it may have been a mix of the two in my case. I did start the truck once I got the torque converter unbolted didn't have a rattle but the flex plate was wobbling maybe ⅛” Quote Link to comment Share on other sites More sharing options...
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