Advice needed: Flex plate area noise???

[78Buford]

For the past month or so, I’ve been hearing a noise from my truck, and I don’t know what it is. Here are the symptoms:

When going forwards, it makes no noise whatsoever. If you put the auto trans in reverse under load (backing up a hill or even sitting still holding foot on brake while applying throttle in reverse) it makes a sound similar to fan blades hitting metal....the sound seems to be coming from the torque converter/flex plate area. I am certain that the motor mounts are good (they are solid steel mounts), as the engine does not budge when placed under load in forwards or reverse. I’m sure that the fan is not hitting anything, as it has no shroud and is nowhere close to any metal objects. I’ve thought that if there was a problem with the flex plate, it would have to make the sound while going forwards...the flex plate and torque converter are always moving the same direction. Again, it only makes the sound while in reverse under load...it does it in 2wd and in 4wd.

Any advice is appreciated.

Thanks,
Roy

[Etcetera]

Originally Posted by 78Buford

For the past month or so, I’ve been hearing a noise from my truck, and I don’t know what it is. Here are the symptoms:

When going forwards, it makes no noise whatsoever. If you put the auto trans in reverse under load (backing up a hill or even sitting still holding foot on brake while applying throttle in reverse) it makes a sound similar to fan blades hitting metal....the sound seems to be coming from the torque converter/flex plate area. I am certain that the motor mounts are good (they are solid steel mounts), as the engine does not budge when placed under loaded in forwards or reverse. I’m sure that the fan is not hitting anything, as it has no shroud and is nowhere close to any metal objects. I’ve thought that if there was a problem with the flex plate, it would have to make the sound while going forwards...the flex plate and torque converter are always moving the same direction. Again, it only makes the sound while in reverse under load...it does it in 2wd and in 4wd.

Any advice is appreciated.

Thanks,
Roy

How much clearance between the torque converter nuts/bolts and the block plate? You might be able to see in there to see if the block plate is marked up. I would think there would be some fine shavings or something if it was rubbing there, but maybe not. What's the endplay on your crankshaft? How much play was there before the torque converter was bolted to the flex plate?

I guess it could be something internal to the tranny but I would think it would be more of a dull noise.

Try unbolting the torque converter and see how much clearance you have when the converter is pushed all the way back into the tranny.

[78Buford]

If anyone has this problem in the future and searches for the same thing:

Check your transmission to engine block bolts. Several of mine had started backing out. I have solid motor mounts, and this likely had something to due with it (the vibrations) I tightened all of them, and haven't had any more noise....since a few days after I posted this question.

Roy

[f250rollinon37s]

broken flex plate - have had a few at work that did that - if the truck was fine before and just started - than i would lean twards that -

[94stepsideford]

your too late

Originally Posted by 78Buford

If anyone has this problem in the future and searches for the same thing:

Check your transmission to engine block bolts. Several of mine had started backing out. I have solid motor mounts, and this likely had something to due with it (the vibrations) I tightened all of them, and haven't had any more noise....since a few days after I posted this question.

Roy