I'll reach out to the mechanic tomorrow and see if he has any paperwork from the job. Unfortunately it wasn't a commercial mechanic and he did it "under the table" so there's not much of a record in means of receipts/ itemized invoices.

As far as trying to bed in the clutch, how exactly should I go about doing that? Hard slip the clutch at a higher RPM and then re-engage as soon as it drops and hold it for a while? Or should I just hard slip and give it some oomph a couple times?

I apologize for my lack of knowledge, being a (retired) mustang driver I'm used to my problems being solved with either a hammer or more throttle. :bonk:

i honestly don't know. the point of bedding brake pads is to heat them and the rotors up to a specific point to cause an even distribution of friction material across the entire rotor surface. a pulsating brake pedal indicates that the friction material is not spread evenly across the surface-- comment methods to correct are to either replace the rotors, or re-do the bedding procedure.

so i googled it...

this basically says everything we already know, but doesn't really help:
https://www.australianclutch.com.au/...lutch-shudder1

this video basically says to do everything you already did, but warns that slipping, or running the clutch hard without those soft stop and go miles will glaze it. so i'm hesitant to say that the clutch needs to be bedded like brake pads where you would intentionally slip it to build up heat...

https://www.youtube.com/watch?v=XMMhDMwtQd8

Sounds dumb, but have you checked tire pressure? With the cold weather, tires are flatter; more rolling resistance to get going. If you’re used to a certain throttle to roll and your tires are low, you will stutter.

Does it shudder with the traction control off?

I slipped my new clutch at above street speeds in those acceleration zones. It helped quite a bit, but it still happened once in a while. But I pretty much doubled the clamping power with my new clutch changing engagement torque beyond the system's design.

My issue came on with a new clutch as well, before my supercharger. What's happening is the bushings aren't tuned for higher sudden torque input, so they over deflect and wind up enough to kick back their energy. Stiffer bushings deflect less and don't kick back as hard. But you gain NVH as they transfer that stiffness into body more. Especially motor mounts

Great feeling to have them stiffer though, the hysteresis on and off power is twitchy again. Came with the most NVH for the dollar, but I do like how it drives quite a bit better now too.

I missed you were all stock in replacement, did you figure out your problem yet? To go from stock to mods and have issues is one thing, but stock to stock, you shouldn't have any change. I'm with Ultramaroon on that one. Catching up on most the reading, it does sound like the flywheel might be burned up a bit. Sounds like it may not have been changed. Thrashing would help seat in with the new disc better and maybe just wear its own groove in and be fine. My settled a bit after the thrashing as well.

On my rig, it's been a while now, but I can still induce the shudder. It's parking lot speeds where I have to feather the clutch a lot, the rear still starts shuddering. On my clutch job, I put in a new subi flywheel. My old one looked a little worn, but wasn't awful. My TOB failed, not my clutch. And I had a SC coming, so I bumped up the clutch strength to stage two and all new parts. Clutch is overkill at 350 ft-lbs, but feels the same weight as the stock clutch foot work wise. But it snaps closed much harder than the stock one, which is where I honestly think my issue came from.

After my experience with mods, and reading your same experience with stock components. I think you need(ed) more wear in time to reset the sliding patch of the new parts. I see the thrashing and slipping the clutch accelerate the burn in process. Especially if a used flywheel already worn into to another clutch pack. Those are smooth compared to new parts and will take a little longer to seat in.

My issue ended up being a Verus fork having sloppy tolerances. Took me 30k miles, but I had it opened back up by a performance shop and they shared that they have seen it several times with Verus forks.

That's a damn shame but it makes sense. Stock fork design isn't stellar but I've always argued that it's strong enough.

What problems could the "sloppy" tolerances cause? Just asking.

Make that 3rd now...

I feel dumb for walking right into it all. Forum-ers, please forgive me.

Sounds like that "performance" shop has a habit of installing clutches wrong, considering nobody else has had any issues.

My car was doing this recently and I installed the front and rear diff bushing inserts and it's doing it a lot less now. It was almost like it was struggling for traction, very strange. Installing bushings or stiff mounts at one end and not the other exacerbates this problem

Sounds like someone doesn't know how these clutches go together, there is no adjustment. The performance shop fixed it, not the installation shop. The performance shop stated they did not find anything incorrect about the installation, just the Verus fork. To which they added they had seen this be a problem with this component before. They claim high wear, but mine was an issue from day one of Verus fork installation.

You can adjust the pedal and thus throw out bearing travel pretty easily though.

Which shop? What has Verus had to say? PRE, AR?

That adjusts pedal position, not TOB engagement. I tried it when I encountered the issue. It doesn't change the throw, if it did, I didn't do it right. And I ran it through nearly it's entire range.

Surgeline was the latest shop. I won't share the original to save them the grief. A part fixed this issue, not an adjustment, so technically, not the first shop's issue, just mine providing them the part(s) that didn't jive. I asked for adjustment. Only the clutch pedal height is adjustable, the clutch TOB hold off of clutch fingers, is not adjustable. I did try, but it's only the linkage and pedal distance off the floor. It does not adjust the hydraulic clutch slave cylinder rod, which would move the fork and allow TOB spacing adjustment to hold it off when not engaged.

I did not contact Verus, I've had it in a while, not going to worry about it. I have no axe to grind with them, really just sharing my experience as I finally resolved this issue and the Verus fork was called out by Surgeline as the root cause of my clutch never fully disengaging. They also mentioned they have seen the same thing on other subarus with Verus forks. They didn't give much more detail than that. I'll still buy Verus parts, this is a one off and I can't even tell if it was truly the fork or a stack of tolerances off or what. Like I said, maybe in another thread, Surgeline did not find anything incorrect with the previous installation to attribute the issue to, just the fork with some wear on the fork, pivot and clutch slave rod. Pivot looked worn the most. But again, this issue was present immediately after installation of the new clutch and parts, it didn't become bad, it started that way.

If worn pivot was the case .. i guess, most won't see such case, simply because most might have chosen to replace both pivot & fork & TOB together (and many others have not worn excessively stock one yet) .. due them all being relatively cheap parts vs cost of work, so why not buy & install new ones preemptively during same transmission drop time.
But at same time i'd probably wouldn't spam forum with many posts of "don't get this part" either.

I thought I was buying something better, just didn't turn out.

I’m a little perplexed. Was the problem with the fork, or a worn pivot?

:iono:

Based on how the system works I would think both would have to be pretty messed up to cause an issue. I'm not ruling out misaligned disc either. Surgeline is a pretty well respected shop around here but that doesn't make them infallible. Offers were made to examine the fork, the other thread got a bit contentious, and it ended there.

I'd also wonder what verus has to say. If it was me, I'd want the part back for examination. Even if that meant reimbursement in full for a used part, I actually do this all the time at my job.