I think my 02 5.3L Engine thrust bearing or reluctor wheel is coming loose

[kingtal0n]

This is my first V8 LS engine ever. When I put into neutral or park, it makes a noise that sounds like cracked flexplate.

Video is here first post (its my thread)
https://ls1tech.com/forums/automatic...eel-noise.html

HPtuner wont let me attach video or I would, sorry about that.

So, fast forward, yesterday, I changed the flexplate (pics if you wana see):
https://ls1tech.com/forums/generatio...l#post19778134

And today, still hear the noise, when engine fully warms. I don't have a code for crankshaft sensor coming up and The engine runs absolutely flawless in gear, and doesn't make any noise in gear, neither forward nor reverse (tempted to just leave it in gear forever)

Finally, sorry, 1 more possibly related thing. The trans front pump makes a whine that is just loud enough to be considered not quite subtle. At low speeds, I can really hear it whining. Once I speed up the road noise right away drowns it out. I am wondering if maybe the front pump is failing, causing the noise. However I have never heard an 4l80e before so maybe its just a loud machine. It certainly was big and heavy enough to make some noise.

[kingtal0n]

update: after playing with trans-idle pump pressure, I am pretty sure its the trans pump making the noise. I will probably attempt to replace the pump. I have a spare trans but would rather keep the one I have working by just changing that one thing.

[GHuggins]

Just to make sure it's in the transmission and not engine related since yours is rather easy to get to - unbolt your torque converter from the flex plate - slide it away from the flex plate just to get some minor clearance " 1/8 inch is more than enough usually " and then fire up the engine while leaving the trans in park the whole time... If the noise is gone then it's front of the trans related - noise still there then break out the stethoscope and see if you can pinpoint the noise anywhere while keeping safety of limbs in mind

[kingtal0n]

Just to make sure it's in the transmission and not engine related since yours is rather easy to get to - unbolt your torque converter from the flex plate - slide it away from the flex plate just to get some minor clearance " 1/8 inch is more than enough usually " and then fire up the engine while leaving the trans in park the whole time... If the noise is gone then it's front of the trans related - noise still there then break out the stethoscope and see if you can pinpoint the noise anywhere while keeping safety of limbs in mind

The problem is, the noise doesn't appear until after everything is fully warm. IF I even shut the car off for a minute, the noise won't be there when I restart it.

I've isolated it to the pump though. I could create the noise anytime I went below 600mv of current to the force motor of the trans when hot. I noticed the "original" tables show 50 and 65psi of pressure for "closed throttle" position (basically sitting in neutral) and yet there is only 20psi of pressure to shift from 1st to 2nd gear when the engine is making like 200ft*lbs of torque. Unless I am reading it wrong. Any idea why the stock table has so much pressure in neutral? Maybe this is why my pump is wearing out?

I went and looked up some pressures for 4l80e and found alot of people saying 150 to 200psi is normal. Which really confuses me because the HPtuner says 90psi is max (I changed it to 80psi). This trans has no trouble with "20psi" holding a very firm shift so I am just wondering everyone's thoughts on this as well. At the moment I can't see any problem with reducing pressures as long as I don't feel any slipping. Wouldn't that only help conserve the pump?

[kingtal0n]

I changed the pump day or two ago and the clattering noise is gone. Still whines though. I have a very quiet car so I can really hear the whine if I pay attn sitting still. Once driving its not noticeable. this should help anyone in the position I was in, where I had never heard the 4l80e before. Yes: it whines from the pump. No: It shouldn't clatter around at neutral hot from the pump. videos are at the top

[GHuggins]

When your out driving, does the whine ever seem to go away? If it does - using your scanner, force the torque converter clutch to engage while listening to the whine - does the whine go away when it's engaged? If it does - you have a bad converter bearing...

[kingtal0n]

I can't hear it while driving. Only at idle in a very quiet setting. my car is pretty quiet. I bet you could be right though: the noise could very well be the torque converter. I will try low 3mph roll in 2nd and lock the clutch in a quiet hallway and see if I can distinguish the noise changing. good idea thank you

I got a camera and you can hear it pretty good at idle in the driveway, and also the electronic noise it makes from under the car. I will hope to post a vid soon.

update: the noise briefly stops/pauses when I shift between gears. So this rules out converter bearings/spinning parts that are still spinning when shifting.

[GHuggins]

This was actually really common in the 4 speeds at one time - I did a lot of torque converters for this whine noise - primarily on the 4l60's of course, but still... If it goes away with converter lock up - it's the needle roller internal to the converter... Sounds like a pump issue every time... Usually much worse than what it sounds like you've currently got, but hey, things never get better on their own - just worse when it's mechanical

[kingtal0n]

I think its just the small car effect, like normally when you buy this trans it would be miles away from the driver with insulation between, whereas in my car the whole car is basically the transmission and ur sittin right on top o it tryin to ride it like a rocket sled. lol

[kingtal0n]

I changed the pump back in 2-6-18 and been driving it without ever hearing that "clattering noise"

However today I accidently threw a code that caused the transmission pressure to go very high. And I can faintly hear the same clattering noise as before just much softer now. Almost un hearable. But it was unmistakable and follows pump neutral pressure.

SO I wonder if the noise is partially natural, it just sounded much worse in my old pump because of its age or wear. Still no idea what it is though.

I saw a video of the pump inside and its just 2 gears. No other parts to really clatter around.

So it got me thinking. Maybe in neutral the pump cavitates at high pressure, or if badly worn out, and that is the noise of little bubbles collapsing inside the pump and damaging the gears or something?