Engine/Transmission (1994 - 1998) Rattling torque convertor

[RRamsey]

When i had my trans built i went with a EBAY triple disc convertor which was a mistake, it rattled until it locked and the stall sucked!! they exchanged it for another and it was no different. so I went to a TCS 3 disc billet low stall and WOW what a great convertor, but it rattles more than the other 2 did. I sold the replacement ebay convertor which was a 3rd unit, it has been installed in another truck and doesnt rattle, I have installed about 12 tcs convertors in other trucks since mine and they dont rattle. I currently am having tcs build another that has tighter intermediate plates hoping it will be quieter. this will be the 4th convertor, i cant believe all of them were loose and am afraid to install this 4th unit and start it up to hear the rattle still there. I have no vibrations, my motor is as smooth as glass, the convertor rattles at all rpms until it locks then is dead silent, it is definately coming from the convertor. I have about 7k on the tcs and hasnt got any louder or quieter. anyone have any ideas??

 

[Joe G.]

Sounds like a flex plate crack to me.

 

[RRamsey]

I have inspected the flex plate off the motor and it is perfect. after 8k miles and the way i drive, a cracked plate would have never lasted.

 

[Joe G.]

You might want to use a dial indicator on the flex plate to see if it's running out. If the TC rattles on your truck and does not on another truck then the problem is not in the TC. About the only thing left is a cracked flex plate or it runs out a little. There are two lengths of the screws that hold the TC on the flex plate so that's another thing to look at. I don't how much different they are, but when I had to buy some for mine I was asked which size I needed. Of course, I didn't have one of the screws with me so I had to go home and get one.

 

[tp0d]

If not flex plate, have you checked the carrier bearing? Mine rattled bad until I took the time to R+R it. . Your drive shaft should have a small amount of movement, but no actual play. now, if it rattles in neutral, thats a different story. .

Theres nothing in the TC to rattle, if it did, it would tear itself apart. I would have begun blaming other things after TC#2

good luck

-j

 

[RRamsey]

It rattle all the time, in gear or not, I know it is the intermediate plates between the clutch discs because i can manually lock the convertor and it goes dead silent. I have put the truck on the hoist and locked the convertor and the rattle dissapears, plus i can hear it goe away while driving when it locks. has anyone had a bad balancer do this???

 

[dieselshadow]

You are describing a flex plate problem to the "t". I also had the same problem with the converter I installed. I spared no expense and bought all top notch stuff. New flex plate, new converter, and all new transmission components. At first when it made this noise, we couldn't figure it out. Long story short, the flex plate to converter bolts were not tight. The flex plate was not compatible with the converter. The converter and the flex plate were not manufactured or sold by the same outfit. The stock flex plate worked fine with the old converter but not the new one. The new triple disc converter has three "bumps" facing the flex plate. It was not flat like the previous "billet" converter. These "bumps" were not an issue with a flex plate that has the same dimensions as the stocker. However the new billet flex plate was interfering with these "bumps" and preventing the converter from fully seating. The converter bolts would never fully tighten down and cause the rattle you describe. I tightened the bolts and went for a drive and the noise would be back after a short while. I would do this again and again only to realize that I was warping the flex plate pulling it to the converter. Once I replaced the flex plate with one that was compatible, i. e. from the same manufacturer, the TC seated fully against the flex plate, the bolts torqued up nicely and the noise went away. This is why it is always a gamble when you mix parts from different manufacturers to come together as a package. It may work well, or in this case brand "X" did not work with brand "Y" parts.

I reread your post again and realized the problem I had may have been different. I never went fast enough to have the torque converter go to lock up. It made the noise all the time from idle to high RPM, in gear or not. I do not recall going fast enough to lock up the TC. My post may not be of any assistance to you but it might help another fellow TDR member who reads this.