New clutch adjustments and squealing/whining noise (1 Viewer)

[kenavt]

Hey folks, I'm having a hell of a time trying to dial in my new clutch on my 2F and would appreciate any help/ideas that people have. It's a new clutch disc and cover (Aisin), new throwout bearing (Aisin), new pilot bearing (Koyo), and then new master and slave cylinders as well (OEM).

I've followed the FSM to set the clutch pedal height to 7.13", free play to <23mm, and adjusted the slave cylinder out all the way... and the truck doesn't really want to get into gear (grinds into reverse, jams going into first). If I set the clutch pedal height higher (longer master cylinder stroke?) then I don't have that problem.

However if I set the clutch pedal a bit higher (more like 8"), then I can get the truck into gear just fine. But when I start lifting off the clutch in gear... I get this loud squeal/whine that sounds quite wrong and really freaking annoying. It has a similar sound to this thread (Clutch bearing type noise when pedal is out, both in neutral and in gear - https://forum.ih8mud.com/threads/clutch-bearing-type-noise-when-pedal-is-out-both-in-neutral-and-in-gear.1236635/) but in the opposite situation - when the clutch pedal is down to the floor and I start coming off, not vice versa.

I'm under the following two assumptions, which may be wrong, but I'm not sure how to address them...

• I'm not keeping enough force on the throwout bearing to prevent it from squealing against the clutch cover when anything tries to slow it down
• I'm not pushing the throwout bearing far enough, at FSM clutch pedal height, to consistently get it in gear without grinding - i.e. not long enough stroke.
  • I've adjusted the slave cylinder so I'm pretty close to - but not touching - the throwout bearing to the clutch cover. I have an '84 slave cylinder so it has the external spring and per this thread shouldn't be touching the throwout bearing. To Spin or Not To Spin...A Throwout Bearing Debate - https://forum.ih8mud.com/threads/to-spin-or-not-to-spin-a-throwout-bearing-debate.983012/

I tried adding more NLGI No. 2 grease to the face of the throwout bearing since I thought it had rubbed off and the FSM says to, but that doesn't seem to help

FSM procedure...

And here are some videos of the noise:

Lower pedal height featuring some grinding going into reverse:


Higher pedal height where I can get into gear but the whining/squealing noise doesn't go away:

 

[OSS]

What you're hearing is the contact surface of the throw out bearing rubbing on the cover spring tangs as the bearing releases pressure. Greasing it isn't doing you any favors as the grease just facilitates it losing traction on the springs.

I think the best way to check the final adjustment of the adjustable clutches is to turn off the engine, press down the clutch pedal all the way to the floor and secure it in that fully depressed position, put the transmission in neutral, then climb under the truck and try to spin the clutch disc (not the cover) with your fingers.
If the clutch is depressed far enough, the clutch disc can easily be spun using your fingers. If you can't turn it, the clutch needs to be adjusted to press the bearing farther in.

You're likely hearing all that throw out bearing rubbing because the bearing is brand new and hasn't been broken in yet. It isn't spinning freely and still has some internal friction.

Until the bearing breaks in, here's a few tips:
1. Don't pussy foot the clutch pedal. Push it all the way in quickly.
2. Don't slowly let out the clutch listening for odd noises. Disengage it as quickly as is smooth.
3. Don't us any more grease for now on the throw out bearing rubbing surface. It's exacerbating the noise problem. You want the bearing to grab the springs, not slide on them.

I found that a brand new throw out bearing needed to be "woken up" in the morning when it was cold. Just press the clutch all the way in when engine is idling and hold the clutch pedal fully pressed like that for a minute or two to warm it up and get it spinning more freely.

 

[kenavt]

Thanks @OSS! I checked the final adjustment the way you suggested - by having someone push down on the clutch pedal and then make sure the clutch disc spins with my fingers. I pushed the pedal height out a bit past FSM (maybe 8") and extended the slave pushrod to near its full length to get that; it now feels close to how it did before.

I'm also trying to shift quickly, but it'll be difficult as I have to park the truck on a hill right now. Hopefully this will settle in shorter rather then later.

This let me drive my truck around for the first time in almost a year next week. Thank you!!