Series 3 Clutch Question

[jac04]

Is the throwout bearing on the Series 3 clutch arrangement supposed to contact the pressure plate fingers at all times (even with the clutch fully engaged)? If so, how is the preload of the TO bearing against the pressure plate fingers controlled?

If there is supposed to be a gap between the TO bearing and the pressure plate, how is it adjusted? It seems that there is no adjustment, and there is a spring internal to the slave cylinder that is always trying to push the TO bearing against the pressure plate.

I'm trouble-shooting a faint chirping noise that occurs with the clutch fully engaged. As soon as I move the clutch pedal enough to put a tiny preload on the TO bearing, the noise immediately goes away.

This may be covered in the factory manual, but I haven't had a chance to check yet.

[msggunny]

Im just going to throw this out as i didnt check the manual either.

it happened to me and i just changed the thing out and did a new clutch at the same time, no more bird in the tranny.

[jac04]

Well, everything is basically new.
TO bearing
Clutch
Resurfaced flywheel
master & slave cylinders & slave pushrod

I don't think it's a 'bad' TO bearing. It makes no noise with the pedal depressed.

[jac04]

I checked the manual, and there is no info on TO bearing adjustment. You just put everything together, then adjust free play at the master cylinder.

Maybe I do have a bad TO bearing, and it only makes noise when lightly loaded. It was a Genuine bearing purchased from RN, and I only have about 60 miles on it. The noise started at about 45 miles.

I just got through putting this vehicle back together. I hate to have to take it apart for a chirping TO bearing. Maybe I'll just keep driving it and see if the noise goes away. Wishful thinking.

[LaneRover]

I just got through putting this vehicle back together. I hate to have to take it apart for a chirping TO bearing. Maybe I'll just keep driving it and see if the noise goes away. Wishful thinking.

Just turn the radio up!

or is this not an ffr?

[kevin-ct]

The t-bearing should not be tight to the pressure plate. you can adjust the master cyl rod to give it some free play.

[jac04]

^^OK, but there is a spring inside the slave cylinder that is always trying to push the slave piston out. This will always try to push the TO bearings against the pressure plate.

I confirmed in the green manual that the slave should have this internal spring.

The more I think about it, the more I think that I actually have an unhappy TO bearing that chirps when lightly loaded.

I may pull the slave & the starter to see if I can look in and see any problems. Otherwise, I may be shifting the trans back just far enough to get in there.

Unfortuanately, on the Lightweight, you need to pull the heater to get the trans tunnel cover off. To pull the heater you need to pull the instrument panel to gain access to the motor wire connections.

[jac04]

Problem Found!

Well, I re-set the clutch per factory specs with the correct free play at the pedal. Drove around the block, and the chirping started. Drove in the garage, blocked the wheels, still chirping. Loosened the bolts holding the slave in place, and the chirping stopped. Pushed the slave back in by hand and it chirped. Hmm.

Now, here is where it gets interesting. With the slave bolts loose & no chirping, I stepped on the clutch and released it. The chirping was back. Loosned the bolts some more - chirping went away. Pushed & released the clutch and the chirping was back. More head scratching.

Completely unbolted the slave, leaving the line attached. I could grab the pushrod & move the clutch fork & TO bearing through its range of motion (at least until the TO bearing was aginst the pressure plate fingers).

I could only get the TO bearing to make the chirping noise by just barely letting it touch the fingers of the Pressure plate. If I pulled it away, the noise would stop. If I pushed on the pushrod with my finger (very light pressure) there was no noise.

So, I determined it was lack of preload on the TO bearing, but why?

I turned my attention to the new slave cylinder. I tried to push the piston back up into the bore, and it was VERY difficult to move. When I pushed the piston in, it would not try to move back out on its own as it should. The spring behind the piston should apply enough pressure to the piston to keep a very slight load on the TO bearing. Mine was sticking, so it was just allowing the TO bearing to barely touch the pressure plate fingers, causing the chirping. As a matter of fact, once I pushed the piston in, I had to press on the clutch pedal to get the piston to move back out. Once it got near the end of its stroke, I could feel the spring pushing a little. Using castrol GTLMA fluid by the way, so it shouldn't be a seal swelling issue.

On my old slave cylinder, the piston would push back out once it was pushed in. I now wish I had saved it! Oh well, I'll contact RN on Monday to warranty this slave.

[jac04]

Well, I still have this problem. RN sent me another slave, but that one suffered from a sticking piston as well. Les confirmed that the slaves they have on the shelf also stick, and that the bores are tapered slightly. This causes the piston seal to become tighter in the bore as it is pushed in.
I guess I could try to hone the cylinder bore to free up the piston seal, but I have no way to measure to bore to see if I have gone too far (and end up with a leaky slave cylinder).
Maybe I'll try another Girling slave from another source. Could be a bad batch from Girling.

[SafeAirOne]

Well, I still have this problem. RN sent me another slave, but that one suffered from a sticking piston as well. Les confirmed that the slaves they have on the shelf also stick, and that the bores are tapered slightly. This causes the piston seal to become tighter in the bore as it is pushed in.

Unusual. I've received defective parts from other suppliers before but never RN.

[jac04]

Update:

I tried installing a stiffer spring inside the slave cylinder, but the chirping noise came right back as soon as the vehicle warmed up. So I pulled the slave with the vehicle still warm, and the piston was stuck in place. The spring could not move the piston back out, even though the spring I installed was significantly stiffer than the original.

The piston seems to stick worse when things are warmed up. This may be due to the difference in thermal expansion between the steel piston and the cast iron body. The steel piston expands at a greater rate than the cast iron body. If the bore is a little on the small side, then this could cause additional binding (maybe, just reaching for some type of explanation).

To get a second opinion, I talked to Trevor at the 'Farm this morning. When I told him about the piston sticking in the slave, he immediately stated that this should not be happening. He pulled an Allmakes slave off the shelf (alloy body). He pushed the piston in with his finger and it came right back to its original position. Hmmm. He didn't have a Girling cylinder to compare it to.

So, I have decided to install an Allmakes slave cylinder and see if that takes care of the problem. I try to use OEM parts whenever possible, so I'm a bit leary of using an aftermarket slave cylinder. Trevor told me that he has been using & supplying these for quite some time with no complaints, so hopefully they are good quality. I guess we'll see.

[Jim-ME]

Trevor stands behind his merchandise. You don't have to be concerned about his stuff. I've had one well known shop owner tell me that 50% of the bits he buys are junk. I'm not 100% sure that in this day in age that genuine bits are all they are cracked up to be unless they are NOS. I feel that this is one price we pay for driving old iron.
Jim

[SafeAirOne]

Trevor stands behind his merchandise. You don't have to be concerned about his stuff.

Agreed wholeheartedly.

[jac04]

Yeah, I know he'll stand behind it, I just want to be sure that he doesn't have to. I also want to avoid having to replace the slave cylinder 2-3 years from now because of quality. That being said, Trevor was very up front with me about the country of origin of the part (which actually doesn't mean too much these days). He advised that quality appeares excellent and he has had nothing but good results with them.

I'll report back later.

[alaskajosh]

It was hydraulic cylinders and their seals that taught me that the whole "Genuine Parts" thing wasn't all it was made out to be. Ill fitting and problematic, in my experience.

On many parts Trevor has a range of aftermarket options.. everything from cheap, up to very nice (and probably gobs better than "Genuine"), with a few choices in the middle. I've never been anything but impressed by the quality, though I seldom select his cheapest option. He'll get them all out, while on the phone with you, and tell you which looks good (machined vs. cast, overall impression of quality, etc) or if one seems identical for less money.

Good luck sorting your issue!