Bucking after new clutch install

[Spuds]

I am going to have both a stock fork and a verus fork next to each other in the near future. I can try to get some sort of comparison...

[soundman98]

Originally Posted by Spuds

I am going to have both a stock fork and a verus fork next to each other in the near future. I can try to get some sort of comparison...

it's entirely possible that jeepmor got a bad fork. bad production runs do happen.

what i find most odd is that it seems only a single performance place seems to see problems regularly with these forks, and the rest of the aftermarket performance world seems entirely scrubbed of the details of it.

with all the interaction and testing verus regularly does, it's hard for me to believe that they're intentionally malicious with this. i mean, business is as business does, but verus has always come across as above the board to me.

something keeps screaming to me that there's a lot more to the story somewhere here, i'm just not sure which side there's more to the story.

[NoHaveMSG]

Originally Posted by soundman98

it's entirely possible that jeepmor got a bad fork. bad production runs do happen.

what i find most odd is that it seems only a single performance place seems to see problems regularly with these forks, and the rest of the aftermarket performance world seems entirely scrubbed of the details of it.

with all the interaction and testing verus regularly does, it's hard for me to believe that they're intentionally malicious with this. i mean, business is as business does, but verus has always come across as above the board to me.

something keeps screaming to me that there's a lot more to the story somewhere here, i'm just not sure which side there's more to the story.

Yeah, it's not outside of the realm of possibility it didn't get a full power ka-chunk. It is just odd and it would be nice to know a few more details and have them all in one coherent thread instead of several.

I realized I responded to the other thread because I clicked the new post tab

Which shop? What has Verus had to say?

[Ultramaroon]

My offer to inspect it still stands.

[RedReplicant]

Yeah, I am curious since I have them in both of my BRZs. They're clearly from different production runs based on stocking at time of purchase too.

[NoHaveMSG]

Originally Posted by Ultramaroon

My offer to inspect it still stands.

Hell, I'll send my fork up to you to compare as well to see if they are built different.

[jeepmor]

Originally Posted by NoHaveMSG

Like this ? This is a used fork I picked up.

My pivot pocket is worn more than that and has a small button in the center as the pivot has a hole drilled in the top like the one at the link.
https://gbpperformance.ca/en/clutch-...ubaru-brz.html

You guys are going all out trying to figure this out. Well done. Could you share a pick of the fork section. The clip retainer holes on mine are not the same distance from the fork end.

I'm starting to half wonder if my old pivot pin was reused on the first clutch change and is the actual root cause. If it's worn too much, it would foul up tolerances, but one would expect to be too loose this way, not too tight engaging the clutch slightly, which was what was happening. This one still puzzles.

[NoHaveMSG]

Originally Posted by jeepmor

My pivot pocket is worn more than that and has a small button in the center as the pivot has a hole drilled in the top like the one at the link.
https://gbpperformance.ca/en/clutch-...ubaru-brz.html

You guys are going all out trying to figure this out. Well done. Could you share a pick of the fork section. The clip retainer holes on mine are not the same distance from the fork end.

I'm starting to half wonder if my old pivot pin was reused on the first clutch change and is the actual root cause. If it's worn too much, it would foul up tolerances, but one would expect to be too loose this way, not too tight engaging the clutch slightly, which was what was happening. This one still puzzles.

I will post a pic in a little bit, mine isn't even either on the clip retainer holes. I do have the Verus pivot as well.

Edit:Pic now attached. The little retainer hole is centered on each pocket.

[jeepmor]

Mine is the same for those pockets, just couldn't figure out why. Probably just how it clips into the TOB.

Thinking of mine in regards to tolerances and my clutch never fully disengaging.

1. My Southbend 2, an Exedy product tip to tail, may have it's clutch fingers out further than EOM.

2. I don't think they changed the clutch pivot on first clutch change, but one would figure this wear as an engagement issue of being too loose, not too tight. It was replaced when I had it gone back into recently.

3. Brand new OEM flywheel, leads me back to clutch pack thickness being too thin, not thick, moving the fingers out. Replacement flywheel had wear, I don't recall in any hatching/machine marks left.

4. Clutch thickness. This puck style clutch is new to me, but it seemed thinner than OEM to me at the time, which would put the fingers out more respective of TOB position all things being equal.

5. I still don't fully understand why this happened, I just know going back to OEM addressed the issues I was encountering.

6. All said, per my Verus fork and my condition. It seems it would need a pocket deeper, not shallower.

7. I'd like a more adjustable clutch system. If I just had some mounting adjustment in and out of clutch slave cylinder, this would have been a simple fix. Adjustable rod length or bolting position of clutch slave cylinder is all it would take as long as nominal throw spec remains. This is fixed via the slave cylinder and linkages currently. It would only take a minute to adjust like my jeep example of the adjustable rod length on it's clutch fork. Same conditions though, no adjustment of throw, just fork hold off TOB.

Sometimes tolerances stack and fail. I studied the bejesus out of this in engineering roles in solar. Being my condition was too tight keeping clutch never fully disengaged, this part was too tight. Which means that's still too much material in the way and technically, I could have just dremel balled the slave cylinder pocket out and made it work, or slot the slave cylinder mounting to back it off.

[Ultramaroon]

Originally Posted by jeepmor

7. I'd like a more adjustable clutch system. If I just had some mounting adjustment in and out of clutch slave cylinder, this would have been a simple fix. Adjustable rod length or bolting position of clutch slave cylinder is all it would take as long as nominal throw spec remains.

These statements indicate a lack of understanding in how this clutch mechanism works. As unpleasant as it is for me to call attention to this, it's necessary so other folks don't get the wrong idea.

[jeepmor]

Originally Posted by Ultramaroon

These statements indicate a lack of understanding in how this clutch mechanism works. As unpleasant as it is for me to call attention to this, it's necessary so other folks don't get the wrong idea.

Why don't you just share the adjustments instead of being condescending? I understand how a hydraulic and linkage clutch work quite well, where is this adjustment you profess I don't know about? You taking a stand on pedal stroke adjustment when we need to be talking about fork engage adjustment? The only adjustment available, per your links, is this one.


https://gt86stuff.onrender.com/t3Por..._rm_index.html

[Ultramaroon]

Originally Posted by jeepmor

Why don't you just share the adjustments instead of being condescending? I understand how a hydraulic and linkage clutch work quite well, where is this adjustment you profess I don't know about? You taking a stand on pedal stroke adjustment when we need to be talking about fork engage adjustment? The only adjustment available, per your links, is this one.


https://gt86stuff.onrender.com/t3Por..._rm_index.html

This part is always the reason I hate having these conversations just as much IRL. Next time you have a chance, Reach behind your fork and squeeze all the hydraulic fluid out of the slave cylinder. That should clearly explain how the system automatically adjusts itself to clutch wear.

[jeepmor]

Originally Posted by Ultramaroon

This part is always the reason I hate having these conversations just as much IRL. Next time you have a chance, Reach behind your fork and squeeze all the hydraulic fluid out of the slave cylinder. That should clearly explain how the system automatically adjusts itself to clutch wear.

You should lead with this next time. Don't worry about being so sensitive and just get to it and share your knowledge.

What you describe is a proper length spring in the slave cylinder behind the hydraulic push cup that sets adequate hold off of TOB bearing while simultaneously keeping the system tight enough so nothing drops out of the push pocket on the fork assembly. My jeep uses an external spring to keep the push pin and fork together to address this on the bellcrank assembly. My adjustable length push rod sets the TOB hold off gap. The spring keeps it all from falling off by holding it tightly together.

This is out of sight in the slave cylinder doing the same thing to keep the slave cylinder charged and the assembly adequately tight so the rod doesn't fall out of the clutch fork pocket. Same result, different means. But this is fixed, without adjustment. The "self adjustment" you profess is just that spring in the slave cylinder. I like the adjustable rod length better, it would have taken just a couple minutes to properly gap it with an adjustable length pushrod for this issue, but instead, it cost me over a grand to go back in and put a 28 dollar OEM fork back in it. Bright side, new oil seal while they were in there. Downside, in this case, is the Verus fork. If it was the clutch, I'd still have the same problem regarding the TOB hold off and clutch semi-engaged, and I don't.

[Ultramaroon]

Originally Posted by jeepmor

...

This isn't your jeep. There's no gap. The TOB stays in contact with the fingers. Don't argue. Go look and learn. Think about how this system manages to to do this without need for adjustment as the clutch wears.