5-Speed Clutch pivot question

[dylone]

PROBLEM: Let me just start with the pictures to explain the situation. I just removed the transmission to find the pivot pin (brass upgrade) squashed to a nub, the clutch fork is also very worn, and the slave cylinder push rod is squashed as well. The clutch fork clip that holds it in place was also broken and rolling around the bottom of the bell housing. SO I'm guessing the fork got unaligned and the offset angle caused it to push way harder on pivot pin?

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BACKSTORY: About 4-5 years ago now I had the clutch replaced by a bmw specialty shop. I had just absorbed the car from my dad and was new to mechanic work so it was just an OEM replacement of the original ~150k mi clutch. They also did the brass pivot pin upgrade at that time. Clutch was great, until about 1-2 years later when I got a squeak every time clutch pedal was engaged.
This is where the squeaker saga began.... I've been hunting this squeak for years; Since then I've replaced the clutch pedal bushing, I've installed brand new master and slave cylinders thinking it was hydraulic, but no. Squeak got worse and worse over time, I determined it was a problem within the transmission but I needed the car as a daily for the longest time and I was still able to get into gear so I dealt with it. Other symptoms that started were, the clutch became very hard to press, the pressure required increased as the car warmed up. During cold starts the clutch felt OK, but once I had been driving it was sometime hard to get into gear. I had also removed the clutch stop at this point because the clutch started to not fully disengage without fully depressing clutch (im guessing this is how the pivot got smashed). The other side of clutch fork has a wear spot where it was grinding against the clutch plate, probably also from over-engaging. In the last year I got a new daily and a garage space, and was finally able to drop the transmission to find whats mentioned above:

QUESTION: Have any of you seen this nub destruction before? What could've caused it? Just unaligned clutch fork?

Also what should be replaced? The Slave cylinder has only ~10k miles on it but if pushrod end is squashed maybe I'll need to replace? I'm going to try to remove pivot pin but I'm not sure if the mounting location is ruined.

Side-problem: In the last couple years, I've noticed a whirring/grinding sound coming from transmission when car is IN-gear and clutch pedal is NOT pressed. I think this is caused by input shaft bearing? If you guys have any opinions, let me know.

I'm thinking to just source another used transmission all together... In the meantime, I already have a stage 2 clutch and shifter rebuild kit ready to go.

[jclausen]

Replace the slave get the new throwout bearing arm and put the oem pivot in lube all points and input shaft splines and tip gear noise who knows

[blckstrm]

I had the exact same thing happen to me.

That brass pivot pin is ridiculous, and that's the only thing that failed (though it may have damaged the other stuff, too). It's practically made from butter.

The stainless pin from the old 8 series is a perfect fit, or just go back to the stock plastic piece.

[zellamay]

I'm not the expert here, but I just did my clutch, used the stock pivot pin because the experts here say that is the one to use. Maybe the culprit is that brass pivot pin. If the brass pin wore down, causing the clutch fork to be working at an extreme angle, it would cause you to need more clutch pedal travel to disengage the clutch. Maybe the extreme angle also pushed that spring off, mangled the end of the slave pushrod, and caused the clutch fork to hit the clutch plate. Maybe all you need is new: stock pivot pin, clutch fork, TO bearing, TO bearing sleeve, spring, slave cyl.

[blckstrm]

There is no "maybe" about it. The brass pivot pin is the clear and only culprit here, though as I said before, it may have damaged the other components. But it is NOT your transmission.

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The only arguments for the stock plastic pin over the stainless pin I've heard is conjecture the stainless pin will squeak, whereas the plastic one will not. This has NOT been my experience. As if the car isn't 23 years old with 248k miles. I'll take robustness over some miniscule amount of additional noise any day of the week and twice on Sunday. I'll also point out that BMW didn't flinch in using this on the far more luxurious 5 Series and 8 Series.

So yes, this is a factory part of the more expensive cars. You can get it at a dealer, though I'd suggest FCP (https://www.fcpeuro.com/products/bmw...in-21511223281 ). The cheaper car (the E36) got the plastic one.

Claiming the plastic pin is superior seems like a pretty weak argument (not that I'm arguing the plastic one is bad per se. But if there's a FACTORY stainless part to replace a plastic one...).

Dimensionally the plastic and stainless pins are identical. Pick whichever one floats your boat.

Here is what my brass pivot pin looked like. The clutch fork was obviously propellering inside the bell housing. At least you didn't have that going on. And even then, it didn't cause near enough damage to the bell housing to make me even consider replacing the transmission.

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[dylone]

Thank you, friends

In my memory I've always heard to replace the stock plastic pivot with a metal one. I never saw anything about the brass one flattening, but I'm glad I'm not the only one its happened to.

I do agree the stainless steel option is the overall optimal way to go. But I think i'm going to rock the stock plastic nub, just because its like $2 and I don't think i'll need that extreme longevity that the S.S. gives.

The clutch fork was obviously propellering inside the bell housing.

^^I'm glad it didn't get to this point

I think I will try to re-use the transmission. I more wanted to replace it because I'm thinking input shaft bearing is grinding, and from what I've read it is not worth effort to replace that bearing. BUT since all my gears are good and detents are good, I'll see and maybe, hopefully, the grinding was caused by one of the damaged parts.

Looks like I'll just order another pivot pin, clutch fork and slave cylinder for now.

[tjm3]

The old, original plastic pivot did crack, usually before a clutch job was necessary, but the newer ones appear to be made with better materials. They should last for the life of the clutch (and parts), usually. As for the metal pivots, they squeak even though the bronze units are supposed to be made of a self-lubricating (whatever that means) silicon bronze alloy. If you actually have one that is advertised as 'brass' then someone picked a poor choice of materials for this application(too soft). My suggestion in other similar posts is if you use a metal pivot, install a way to inject some lubrication to the pivot tip. Since the back of the pivot is accessible from the back of the bell housing, the easiest way is to drill a small hole right through the center, chamfer the pivot end and tap the other end for the smallest grease fitting you can find. This way you can shoot a bit of grease at every oil change. Or drill a small hole in the bell housing that points directly to the wear surface on the pivot and give it a shot of grease now and then. Both methods work. Haven't had any issues with the silicon bronze pivots although my latest 325i driver has the plastic unit.