• Welcome to The Truck Stop! We see you haven't REGISTERED yet.

    Your truck knowledge is missing!
    • Registration is FREE , all we need is your birthday and email. (We don't share ANY data with ANYONE)
    • We have tons of knowledge here for your diesel truck!
    • Post your own topics and reply to existing threads to help others out!
    • NO ADS! The site is fully functional and ad free!
    CLICK HERE TO REGISTER!

    Problems registering? Click here to contact us!

    Already registered, but need a PASSWORD RESET? CLICK HERE TO RESET YOUR PASSWORD!

Unidentified noise that seems to be coming from around the TC or flexplate area

dbrannon79

I'm getting there!
Messages
5,325
Reaction score
11,375
Location
Seguin, TX
Guys, my 93 has developed a noise that I need some help identifying. It's a high pitched banging noise that almost sounds like something to do with the flex plate.

I double checked to make sure the front pulley and HB were doing ok, they both seem fine. I have a fear that ether the flex plate to crank bolts are loose or the flex plate might be cracking. the noise only goes away under a heavier acceleration. dropping in gear or light acceleration doesn't change anything. And the noise is quite pronounced when the engine is cold too. it seems to subside a little after the truck warms up.

I did slide up under there and check the torque converter bolts and try rotating the flex plate, wiggling and what not but cannot find anything.

Here is a video I made of it running up to full temp while I had it on the ramps.

 
After all that I have found on this truck, I'm wondering if the flywheel to crank bolts are loosening. I might attempt tomorrow after work unbolting the converter and pushing it back and running it. Not sure if there is room in there to stick a wrench to get a bite on the bolt heads by doing that.
 
I think you nailed it- flex plate.
Get a tube of loctite, can of brake cleaner and your favorite wrench and flywheel turner. Torque wrench is a smart one for this option- just saying. Torque check paint tube is smart also. I like the red personally.

Start and spray the brake cleaner with eyes and mouth wide open to catch it flying off so you can feel, see, and taste the burn. Or safety stuff- whatever. Haha

Follow your plan of slide back the TC. Clean and inspect. Use turner to carefully inspection it both sides all the way around.
Loctite and torque them up, marking so you don’t have to guess in the future if they came loose later.
 
I really hope that the flexplate isn't cracked.... That job isn't fun. I did this on the 95 and somehow managed to just slide the trans back about 8 inches to replace it.

I know just sliding the TC back won't allow enough room to pull a bolt out, but maybe allow a open end wrench up in there to the lower bolts.


What a joy, this is a big Easter egg to find on Easter Sunday HAHA This truck has been full of them just waiting to be found.
 
Well, I just unbolted the TC from the flex plate, inspected everything to the best I could. No evidence that the flex plate is cracked or is loose on the crank. there is not enough room to get a open end wrench in there to check the bolts, but I did place a vice grip in the flex plate and try to move back n fourth. the only play I got was the entire crank moving with it.

start the engine with the TC pushed back and it's quiet as a diesel mouse! What gives??
 
Well blow me away once again.... I just finished re-attaching the TC to the flex plate, started it up and guess what.... the noise is gone!

I think I need to drive it a bit and see if it comes back. the only difference is that the engine and trans is cold where before it was up to operating temp. crazy thing was that this noise was more pronounced the other day when it was cold. I also heard the noise this afternoon while driving it up on the ramps, so I know I'm not going crazy here.

all the TC bolts were tight, I had to use a cheater pipe on my 3/8" long handle ratchet to get them all loose. I'm assuming that disturbing the TC mounting and now that it's re-attached not in the same holes as before made some kind of difference. Time will tell I suppose.
 
I think I have a new plan of action. this will hopefully solve some of the things I get hit with. some of the most odd ball uncommon situations.

next time I hear a weird noise like this, I will just turn up the radio and keep driving HAHA.

LOL I really feel like I get faced with some of the most odd issues rather than the more common simple fix ones sometimes....
 
Puzzling that the sound is gone and there are no small cracks in the flexplate.
Need a stethoscope at this point.
Still can’t find it- then put the stethoscope against the speaker. Haha
 
I just returned from driving this truck to pick up dinner (Chicken Express Tuesday's special) and absolutely no noise like this at all! if the flexplate is cracked, it's not fully developed where it's raring it's ugly head yet. we shall see what happens in the coming days!

Edit: Monday's special. I forget what day it is sometimes
 
Last edited:
Back
Top