Torque converter noise?

[bigpatofpa]

I installed a used tranny and torque converter. I needed to re tune due to fmic install. I drove car for 10-15 miles no issues. Get back to my garage, turn car off, 10 min later i start back up. Now it makes a clanking / knocking noise, that is coming from bell housing. Fluid is new and at normal level. I thought it may be flexplate to converter bolts or flexplate to crank bolts. I removed xfer case and inspection plate flexplate bolts were starting to loosen, re torqued and replaced starter. I used a pry bar lightly while holding crank bolt to prevent movement to see if crank to flexplate bolts were loose. They appear to be tight without pulling tranny. I re assemble everything start the car, no noise, i rev it up a little and at 2500 to 2700rpm and up it still makes this clanking knocking noise, however it is quiet up to that point.
Did something break loose in the tc?
Any input would be appreciated

 

[DSM1G90]

Flex plate can break without knowing.
I had a flex plate replaced since my 1.8L with the auto was experiencing the same noise. Also.... the diversion blades inside the TQ could had destroyed each other. New converter then is in store.

 

[evo9mrtt]

First, did you fill the converter before you installed it on the car? If not the trans pump is probably struggling to keep the converter filled or possibly not filling it enough. And second did you use locktite when torquing the flexplate to converter bolts? Iv seen people who have re tightened their bolts and with in miles their loose again. Another thing you might try is take the inspection plate off and start the car. The bolts might be rubbing. Look at the inside of the plate to see if this is happening also. Happened to me. I just got a new inspection plate and re torqued the bolts with locktite and have had zero issues to this day. Hope this helps

 

[bigpatofpa]

Ok finally got to pull the Tranny. No rubbing or contact of any metal anywhere . Pulled the flexplate, its difficult to explain I will post photos, saw indication of heat on flexplate. No cracks or breaks. It almost looks likethe holes were elongated and someone welded them up and redrilled the holes. And the welds started to melt.don't question my sanity until u see the pics.this issue on the flexplate galled the face of the crank also. Don't remember seeing this at install. Hopefully somebody can explain this.

 

[DSM1G90]

Someone didn't use LOCKTITE on the TC bolts when attaching the TC to the flexplate.

Bolts worked loose just enough to cause the hole gouging on the flexplate.

Prob, this hole gouging creates tonnage of heat to do damage where the flex plate became a huge heatsink.

Definitely time for a new flexplate. And a tube of Locktite to put on the TC bolts since they don't have a lockwasher to hold them in place.

 

[Spyderman7]

When the converter bolts back out It makes a nasty sound and will cause the bolts to egg out the holes and it can also chew up the pilot bushing that goes into the end of the crank and on the converter where it slides into the bushing.It will also beat the threads up on the bolts.Have to use locktite or you will be replacing these parts over and over

+1 new bolts
+1 new flexplate
+1 on the locktite
maybe new pilot bushing as well

 

[DSM1G90]

..agree with the pilot bushing - loose TC bolts raises hell with the bushing..

 

[bigpatofpa]

before you see the pics, i will say that i came to the same conclusion. I originally took off the xfer case and inspection plate and found the tc to flexplate boltes were loose. i cleaned them loctited them and reinstalled, torqued and sat for 24 hours till startup. i figure it started to work the crank bolts just loose enough (these were loctited) to allow what little play were in the holes to beat on the bolts, more movement and cause the heat issue. When i took the flexplate off the bolts were tight and loctite. This is what i saw

also the pilot bushing came out by hand. i could feel very slight side to side movement. might as well replace that too, right? tell me the crank is still useable. i got 11 new bolts ,flexplate add a bushing and spacer plate? I still find it hard to believe that was the cause of that loud of a noise. Should i get a cheap rebuilt tc? I had flywheel bolts back out on me and a rod knock, this soundrd like a combination of both.

 

[DSM1G90]

Bit concerned with all of that damage on the end of the crank - whether that main seal likes it or not.

With that one hole all buggered up, really doesn't look good since that'll always be a weak link in the system of a rotating mass.

Good luck - DSM

 

[bigpatofpa]

There's no thread damage. Its loctite dust, and there doesn't appear to be any seal damage, physical or leaks.