Throwout Bearing chatter - with video

[Mudtrac]

Good day, We have been very busy replacing everything we can get our hands on for this truck so naturally pulling the transfer case and transmission were on the agenda. When we first got the truck we noticed some transmission chatter, figuring this was the clutch we ordered a new clutch, pressure plate, flywheel and throw out bearing from Memphis. After resealing and painting the tranny and tcase and putting it all back together it was very sad to hear the transmission making the same noise. I have worked on some cars that have the throw out bearing ride the pressure plate fingers and some that do not. I pulled the lower bellhousing cover and inspected the Jeep and noticed that the throw out bearing is not disengaging from the pressure plate. Is this normal?

The noise happens at idle in neutral and in 1-3 but it seems to get more quiet in 4th. If you engage the clutch the noise gets better. There are no hard shifts and the clutch seems to be adjusted right. Never seem to hear any other noise from the transmission other than this.

below is a video of this happening.

https://www.youtube.com/watch?v=uJQrwAxyweU

[BlessedM715]

I had the same noise and after replacing everything like you did it ended up being the new bendix on the rebuilt starter rubbing. I shimmed the starter and it went away!
(after a bunch of unnessary expense and effort!) I laser cut some extra shims if you need any.
Thanks!
Mike

[Mudtrac]

Does the bendix change its engagement based on the clutch? Seems like its position would be static in relation to the flywheel. I'm just wondering because the noise goes away as you depress the clutch peddle. I can pull the starter off and see if the noise goes away I guess. I'm mostly concerned because the TO bearing never disengages. When there is a load on the bearing the noise goes away / gets quieter.

Thanks!

[Mudtrac]

So i went back out and re-adjusted the clutch, My TMs don't have a very good description of how to do this. I was able to get the throwout bearing to not be engaged and still have good disengagement for the clutch. I have to believe this is the way its supposed to be. Some of the noise is gone now, but I think I might still have a main shaft bearing in the transmission making some noise. I did remove the starter and checked to see if there was interference but there was none. I think I will have to pull the top plate or PTO to inspect the gears in the trans to make sure its not something more serious. I think I saw that there is a rebuild for the T98 big shaft from Novak https://www.novak-adapt.com/catalog/...arts/t98-parts

I've been searching in the Stock Tech forum but have not seen a good review or DIY for this yet.

Thanks

[gerrykan]

I was able to get the throwout bearing to not be engaged and still have good disengagement for the clutch. I have to believe this is the way its supposed to be.

You are correct.
The throwout bearing only has the grease it left the factory with for lubrication.
If it is always engaged, it will turn every RPM the motor turns, causing premature failure.

[Don Cavey]

You are correct.
The throwout bearing only has the grease it left the factory with for lubrication.
If it is always engaged, it will turn every RPM the motor turns, causing premature failure.

For sure, "What he said"... and that basically pertains to just about any manual transmission.