FR-S Extreme Clutch Problems
 

Hello all, I just joined this forum today in order to get some help on some extreme clutch difficulties I have been experiencing. I have searched far and wide to no avail and have changed quite a few parts in the process. Bear with me and read it all if you can, it is pretty in depth. And for god sake's please don't just give me the "bleed the clutch, its the TOB, adjust your pedal bs" before you even read what I have to say.

Three months ago I purchased a used 2013 FR-S, before that I had a 2014 FR-S that was totaled. The vehicle seemed in decent condition at the time, it had dings here and there but overall the engine seemed well and the previous owner swapped the fuel pump out (bye bye annoying chirp!). Everything was dandy until about 300 miles off of the used dealership lot.

I started to notice a chirping sound similar to the fuel pump chirp, yet this one was metallic in nature. It was much louder than the ones I had heard before. Me being quite sensitive about my cars well being, I popped the hood and listened in. After some looking around I noticed that the clutch fork was wiggling left and right, and it was squeaking like crazy! To make matters worse, pushing in the clutch alleviated the noise.

At this point I decide, it is definitely the TOB, I will order a new clutch and have it replaced ASAP. And so I did. In the process I bled the clutch, replaced the transmission fluid, reattached a new Exedy OEM copy TOB, Clutch Plate, and Clutch Disk, and went on my merry way. Except.. I didn't go on my way.

After the install, the car would not go into gear, and in my head I instantly thought to the clutch needing another thorough bleeding. I did so, and viola! The car sat right into gear like it should have in the first place, but everything was not so great. The squeaking was worse than ever - and not only that, but every time the car was stopped and restarted the clutch needed another bleeding.

At this point I was certain the slave cylinder or the master clutch cylinder was bad, so I started by replacing the slave cylinder - and additionally adjusted the clutch pedal to try and find a spot where the clutch would properly disengage..

Here's where things started to get weird.

The clutch began disengaging at different heights on the pedal, sometimes it wouldn't disengage at all. The squeaking became absolutely horrendous, so I decided to squirt some high temp grease into the clutch forks boot. It did help a bit, but it is not completely gone. The car is now completely immobilized due to the fact I cannot get it in gear. No matter how many times I bleed the clutch, or adjust the master plunger, or gravity bleed the entire clutch system. The clutch pedal is also much softer than it originally was, however it still does take a little bit of pressure to get it all the way down. Meaning that it still has pressure in the system, just likely not a lot of it.

So far I can only come to possible the conclusions that:
1. The Master Clutch Cylinder is bad in some way. However I have visually inspected the reservoir whilst the clutch pedal is depressed, and the liquid inside does not change levels.
2. The lines between the MCC and the Slave are leaking in air so badly that the system cannot function. However I have vacuum bled through the slave nipple and no air seems to come through.
3. Something inside the clutch itself has malfunctioned. However, the entire system, save the flywheel and clutch fork are brand new.
4. Brake fluid is absolutely everywhere at this point and I just want to drive my car again.

Any insight or answers are gratefully appreciated, and if you have similar problems, head to the end of this thread and I will do my best to have the answers posted.

Hello Japanese_Carbon and welcome to our fine forum … :clap:

What a go round you are having with your clutch .. :(

As you suspect, I would suggest you replace the clutch master cylinder. I would also order an aftermarket reinforced clutch fork (just in case the old one is stressed out).

Having said that, I'm going to refer you to our clutch expert, ol @Ultramaroon .

He has been a bit cranky here lately, but, hear him out.

I hope you get it sorted out soon.


humfrz

Thank you for the input and the welcome!

I do believe you may be correct about the master, as some symptoms do point to that, but just as well I believe it could have something to do with the fork. Hopefully the clutch expert has some further insight. If not, I suppose its up to luck of the draw buying parts until the problem is fixed. Thanks again!

What squeaking? Did you replace the clutch yourself?

The level in the reservoir does not change as the clutch is operated. That's not how it works.

However, if you pull the fork all the way forward to compress the plunger in the slave, that fluid will flow back into the reservoir. Then you have to wait for everything to flow back into equilibrium, or pump the pedal a couple times to help it along.

There should be no squeak. Post up a video clip of the sound.

Sure thing:

https://streamable.com/s/ekjdx/xhgbnd

Note that the video also includes me depressing the clutch pedal multiple times to show the alleviation of the noise.

Although I can understand your frustration with the fact that the reservoir liquid levels do not change, I simply stated that the levels weren't changing, therefor indicating that there was no weird issue where the liquid was being forced back up upon depression of the clutch pedal.

However, the clutch was replaced by myself, and the squeak was there before, AND after the replacement. The squeak itself is primarily produced from the location of the clutch fork.

Unfortunately the concern lies mostly with the fact that I can no longer disengage the clutch to get the car in gear, and less with the fact that the clutch fork is squeaking. Unless of course you believe they are correlated.

The squeaking in the video sounds like my clutch fork squeaking (I can only hear it when my car is in the garage or up against a wall). I understand that can be fixed by greasing it up.

As for your major problem, I'll still put my money on a bad master cylinder (in light of all the bleeding you have done along with replacing the slave cylinder).


humfrz

I'm not frustrated at all. I'm just being direct. Humfrz was flipping me shit about being cranky.

Sounds like the crickets. Does it make the noise immediately upon startup, or only after it has been running for a while. That's an excellent recording. I can hear your DI system operating. That lends some weight to the cricket observation. I hear zero issues with TOB or fork creak.

Now, on to the clutch disengagement issue. Where does the clutch pedal come to rest in relation to the brake pedal right now? Unless it is already significantly higher than the brake, humor me.

Loosen the cruise defeat switch and back it way out. Then adjust the pedal up high. Does your clutch now disengage?

1. The noise occurs immediately upon startup, and regardless of the engines temperatures the sound does not change.
2. The squeaking can be stopped by resting my hand upon the top of the clutch fork, or engaging the clutch pedal (thus pushing the clutch fork forward).
3. The clutch pedal is raised all of the way, meaning I have utilized the U clip at the end of the master plunger to raise the pedal, and have backed out the defeat switch all of the way.

On the note of pedal adjustments, for a while the solution you provided to disengage the clutch DID work (this was something I had tried on my own before asking), however the problem seems to have escalated beyond the point where the pedal can be raised to disengage the clutch.

Do you believe this problem could lie with the Clutch Master Cylinder?

Thank you for your patience with me.

:D


humfrz

Bah! No patience required! Thanks for being an excellent communicator.

The threaded u-clip is called a 'clevis' Then there's the clevis pin, and the whole thing is called a clevis joint.

...whoops-NVM this one. I gotcha on the second read... So, going back under the hood... With the engine running, if you manually pull the top of the fork forward to back the TOB away from the pressure plate fingers, does it stop squeaking?...

When you push away on the fork, does it feel like the TOB is making solid accurate contact with the pressure plate fingers? Do you feel any wobble while it's in contact?


I'm not yet ready to make a call on the master cylinder. If it was leaking, there are only two places the fluid could go; back into the reservoir, or into your carpet. Neither seem to be the case.

Sorry about the wait! I actually had the vehicle towed today to a shop that is going to take everything apart and look at it.

In the meantime I have my speculation and, while I had the vehicle I did mess around a bit with the fork and hydraulics. When tugging the fork back towards the slave, it did feel solid, and just as well pushing it forward seemed to create a solid contact between the TOB and pressure plate fingers.

I am unsure as to what exactly a solid feeling would appear to be, however there is no wiggle room left and right once the fork is moved forwards or back.

In other news, I removed the entirety of the clutch hydraulics, and took it to the shop for them to diagnose. However, they concluded that the system was fine and intact. I suppose we will have to await the removal of the transmission, and likely the inevitable thinning of my wallet. :cry:

I always like simple first.
You have been looking at the fork, did it move the same distance before and after each bleeding? If no then there is a problem with the hydraulics. If yes then a problem with the mechanical part ie. fork bearing or pressure plate.
I have had times when slaves will not expel all the air and had to be filled on the bench. Very unusual for a clutch system to suck air in after bleeding as it is under pressure from the pedal on the return stroke.
Many strange thing have happened to forks, bearings and pressure plates. Turns , shifts, and broken springs among them.


Beyond that you maybe "lucky" enough to have more than one problem at a time.

I'm having the SAME issue after swapping out my TOB & clutch.
Did you ever find out what the problem was?

So did anyone get an answer to what the issue was? I’m having very similar issues after changing my clutch, flywheel, and throw out bearing as well.

I have an ACT clutch and they use the stock Subaru throw out bearings.


If you look into it the Subaru TOB are known to be very squealy, almost sounds like metal against metal. It annoyed me but after about 2 months of driving it the sound quieted down a lot.


Does the sound go away when you press the clutch in, if so its your TOB and you should just deal with it. People are known to get very long lifespans on these TOB even though they squeal.

Non-throwout bearing related intermittent metallic grinding
 

I have issues similiar to the op, atleast in regards to noises. Im very curious as well if this was ever resolved.
My car has 35000, 2015 bought second hand (my 2013 was killed by a silverado unfortunatly).

All the info I can think of: early days: metallic metal on metal noise, more common on cold starts, but sometimes all the time. Light pressure on clutch pedal stopped the noise of the time. Could also be heard when driving light throttle on decel (off throttle engine braking). Suspected tob, replaced it and entire clutch, all oem parts (everything seemed fine tbh, including bearing). Came back quickly. Very itermittent. When clutch fork is forced AWAY by hand from pp (compressed against slave), sound gets worse. Most of the time.

Today: car has developed starter issues. It occasionally had a crappy engagement/mesh type sound early on, but has gotten worse, when it happens. Also intermittent. Sometumes starter only spins and only catched occasionally. Again, this is itermittent. Sometimes zero drama. Seriously... i replaced the starter with a clean low mileage starter. Teeth on mine badly worn, almost machined off a few mm deep on pinion (will post a pic soon). New starter installed, twrrible grinding metallic noise all the time. Took off and reinstalled original. Teeth on new starter chipped.

More observations: when car makes metallic noise, starter works fine, pushing back and forth on clutch fork at the slave changes intensity. When starter is acting up, metallic noise is rare, hard to replicate is clutch fork, and when car is revved, i get a rattle from that area. Rattle is only present when starter is acting up. Its a heat shield type rattle.

All work done by me (since purchase), all with factory parts, all torqued to oem specs. Will post videos and pics.

I believe trans was replaced at some point as it had a 2016 build date on it

I think these issues are connected. So far im totally drawing a blank, but im thinking warped flywheel maybe? Clutch is very smooth, no engagement issues, chatter, tob feels great. I did have flywheel resurfaced..

Ideas? Its driving me insane!

Hey all, sorry for the long delay. Early last year I ended up taking the car to a transmission shop after I was unable to even get it into 1st gear. When it got there they tore it down and found that the TOB had actually welded itself to the input shaft. In addition, the input shaft was worn down a significant amount. The owner of the shop actually called me in disbelief lol.

I ended up getting a new trans put into the car with an upgraded clutch as well as another new TOB; I haven't have any problems since. Actually went FI this year! All new problems :mad0260:

In regards to you mhansen, I am not sure what could be causing this issue for you. But it sounds like something to do with the flywheel? I would save yourself the hassle and go buy a new one - at least that is what I did when it all went to hell.

I think thats where im gonna start. My car still has the powertrain warranty and I have desperatly tryed to force a Toyota Dealer to fix it, but intermittent problems = money wasted on bs diagnostic fees. Plus 3/4 of those master techs shouldn't be allowed to torque lugnuts (no offense to the competent ones..)

Anyways I dunno how a flywheel could cause any of these issues but something in there isnt right.

So I thought I would conclude this in the unlikely case somebody else has suffered this problem.

It ended up being a loose ring gear on the factory flywheel. Honestly, until I looked into flywheel construction in general, I didnt even realize the ribg gear was a seperate piece, figured it was machined in. But makes sense, they are clearly hardened steel vs cast iron flywheel. Anyhoo, the ring gear was so loose it both moved in and out, contacting the starter pinion and the lower exposed bellhousing mount surface. It also began to spin on the flywheel! I installed a brand new 86 take off oem flywheel and she is finally as perfect as a 36000 mile can be.

So if you have grinding/contact noises and issues on a lower mileage frs/86/brz and have confirmed its not the clutch or tob, have wear on the starter pinion, and after some time develope starting issues, consider your flywheel ring gear!

Pictures showing pinion gear wear vs healthy starter and ring gear gap
 

https://drive.google.com/file/d/12ZF...w?usp=drivesdk

https://drive.google.com/file/d/12gn...w?usp=drivesdk