Bucking after new clutch install - Page 2 - Toyota GR86, 86, FR-S and Subaru BRZ Forum & Owners Community

NoHaveMSG · 12-05-2022, 12:25 PM

Quote:

Originally Posted by RedReplicant

That is an extremely weird source for something like this...

I was thinking the same.

Ultramaroon · 12-05-2022, 02:32 PM

Consider an imaginary plane intersecting the top and main pivots along the longitudinal axis. That plane must bisect the line drawn between the contact points on the tines of the fork.

Is it really the issue? I don't know, but I've considered it.

Spuds · 12-05-2022, 09:07 PM

I have a Verus fork I am about to put in...

soundman98 · 12-05-2022, 09:55 PM

Quote:

Originally Posted by Spuds

I have a Verus fork I am about to put in...

but how many verus forks have been sold, and this is the first related issue to surface here since they developed it in early 2014?

DarkPira7e · 12-05-2022, 10:19 PM

Quote:

Originally Posted by Spuds

I have a Verus fork I am about to put in...

I wouldn't hesitate. I didn't want to say anything, but this sounds more like a shop who makes mistakes is taking an easy scapegoat. I've heard ' oh yeah, we've seen failures after installing those" when it's really just bad installation practices.

I have one installed, many people have them. Go ahead and Google " Verus clutch fork issue" and watch as nothing pops up..

Sapphireho · 12-05-2022, 11:19 PM

I have a Verus fork and pivot and south bend stage 2. Works perfectly for about 4 years now.

Spuds · 12-05-2022, 11:22 PM

Quote:

Originally Posted by soundman98

but how many verus forks have been sold, and this is the first related issue to surface here since they developed it in early 2014?

Quote:

Originally Posted by DarkPira7e

I wouldn't hesitate. I didn't want to say anything, but this sounds more like a shop who makes mistakes is taking an easy scapegoat. I've heard ' oh yeah, we've seen failures after installing those" when it's really just bad installation practices.

I have one installed, many people have them. Go ahead and Google " Verus clutch fork issue" and watch as nothing pops up..

Was still planning on installing it lol. All valid points though. I've never heard of anyone else having issues either.

Ultramaroon · 12-06-2022, 12:21 AM

Quote:

Originally Posted by Spuds

Was still planning on installing it lol. All valid points though. I've never heard of anyone else having issues either.

I think it'd have to be pretty bad. I'm skeptical too. They switched to a forged design but I don't see any finish machining in the pics.

jeepmor · 12-06-2022, 01:20 AM

Quote:

Originally Posted by Wally86

What in the tolerance was sloppy?

Per the mechanic, the clutch wouldn't completely disengage which was my difficult shifting issue.

So the pivot points of contact were less than needed. This could be a pivot pocket too deep or the seesaw contact points not being far enough from the pivots in the parallel plane. This also hints to me my throwout bearing never took any time off.

Quote:

Originally Posted by RedReplicant

That is an extremely weird source for something like this...

I agree, it has baffled me, but it is now a night and day difference. I could put it in reverse on cold days and the drivetrain would shake because the clutch was not fully disengaged. Please tell me how this could be installed improperly, there is no room for adjustment on this assembly. And the shop that fixed it said they've seen several as they are a subi specific legit dyno speed shop. It was not the shop that installed it.

Quote:

Originally Posted by DarkPira7e

I wouldn't hesitate. I didn't want to say anything, but this sounds more like a shop who makes mistakes is taking an easy scapegoat. I've heard ' oh yeah, we've seen failures after installing those" when it's really just bad installation practices.

I have one installed, many people have them. Go ahead and Google " Verus clutch fork issue" and watch as nothing pops up..

I agree, but how could this part not be installed properly. Blame it all on a worn pivot or such. All other parts were brand spanking new. Wear marks on everything were normal, the fork didn't slip off the the TOB at all.

Bottom line, I replaced that part back to OEM and I'm good. You can defend Verus and doubt me all you want. The mechanic said the previous install was sound, and had seen these before. Call Surgeline yourself and ask them to elaborate.

churchx · 12-06-2022, 04:58 AM

Quote:

Originally Posted by jeepmor

Per the mechanic, the clutch wouldn't completely disengage which was my difficult shifting issue.

I wonder if pedal travel was checked/readjusted after changing out clutch fork.

Spuds · 12-06-2022, 08:21 AM

Quote:

Originally Posted by churchx

I wonder if pedal travel was checked/readjusted after changing out clutch fork.

This would be my guess. The aftermarket clutch might have some increased thickness somewhere as well. Also, the oem fork might be flexing a bit more than the forged one. An extra mm could make up the difference.

x808drifter · 12-06-2022, 09:52 AM

#4...

Wally86 · 12-06-2022, 10:36 AM

Quote:

Originally Posted by x808drifter

#4...

?

jeepmor · 12-06-2022, 07:08 PM

From post #4, one of mine.

"Feels like wheel hop on a leaf spring suspension. It is clutch chatter of some sort, just expected it to wear in by now and go away. The feeling from the driver's seat is that the tailshaft of the trans is moving, or the rear suspension connection to the unibody is bucking to and fro its range of motion.

It is a 350 ft-lb clutch."

I really thought it was just the beefier clutch causing the chattering due to the extra torque impulse exceeding the stock bushings design and the stock bushing were now too soft. Namely the rear diff bushings that connect the subframe to the back of the differential.

Also, I have no axe to grind with Verus, I was just told by the shop they've experienced this before with this particular part. They had no negative feedback on other Verus parts, just this one.

Knowing how this clutch goes together, there isn't any adjustment to the fork engagement. If like my old CJ7, I have an adjustable threaded section in my linkage to set the clutch fork hold off clearance so it isn't touching the TOB and spinning it while running. I have no adjustment on the throw distance of the jeep system either, the bellcrank (linkage) assembly controls that, and is fixed.

Subarus don't even have that, and the first shop tried to fix it when I complained about it. All I found on my own was that I can adjust the pedal height with adjustable linkage in the cab at the pedals, but this is not an adjustment of throw distance, or even the clearance setting to keep the fork off the TOB when in gear and clutch engaged, there isn't any adjustment on these like that. But it is nice to lower the pedal a bit so you don't have to lift your heel. If you do this, be careful, it does not take much adjustment to have the clutch engage while the pedal is barely off the floor.
I tried some of this setting both high and low to see if it would change the condition, it did not.

I share this only because I finally got this issue fixed and found the root cause and thought it relevant in this forum.

12-05-2022, 02:32 PM	#16
Ultramaroon 義理チョコ Join Date: Sep 2014 Drives: a 13 e8h frs Location: vantucky, wa Posts: 31,866 Thanks: 52,121 Thanked 36,516 Times in 18,918 Posts Mentioned: 1106 Post(s) Tagged: 9 Thread(s)	Consider an imaginary plane intersecting the top and main pivots along the longitudinal axis. That plane must bisect the line drawn between the contact points on the tines of the fork. Is it really the issue? I don't know, but I've considered it. __________________ service manuals

12-05-2022, 09:07 PM	#17
Spuds The Dictater Join Date: Apr 2017 Drives: '13 Red Scion FRS Location: MD, USA Posts: 9,428 Thanks: 26,111 Thanked 12,430 Times in 6,146 Posts Mentioned: 85 Post(s) Tagged: 0 Thread(s)	I have a Verus fork I am about to put in... __________________ If a picture is worth a thousand words, a model is worth ten thousand pictures. Also: "Build Thread"

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12-05-2022, 11:19 PM	#20
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12-06-2022, 09:52 AM	#26
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12-06-2022, 07:08 PM	#28
jeepmor Senior Member Join Date: Apr 2014 Drives: 84 CJ7, 08 Duramax, 2014 FRS Location: Oregon Posts: 478 Thanks: 338 Thanked 128 Times in 103 Posts Mentioned: 13 Post(s) Tagged: 0 Thread(s)	From post #4, one of mine. "Feels like wheel hop on a leaf spring suspension. It is clutch chatter of some sort, just expected it to wear in by now and go away. The feeling from the driver's seat is that the tailshaft of the trans is moving, or the rear suspension connection to the unibody is bucking to and fro its range of motion. It is a 350 ft-lb clutch." I really thought it was just the beefier clutch causing the chattering due to the extra torque impulse exceeding the stock bushings design and the stock bushing were now too soft. Namely the rear diff bushings that connect the subframe to the back of the differential. Also, I have no axe to grind with Verus, I was just told by the shop they've experienced this before with this particular part. They had no negative feedback on other Verus parts, just this one. Knowing how this clutch goes together, there isn't any adjustment to the fork engagement. If like my old CJ7, I have an adjustable threaded section in my linkage to set the clutch fork hold off clearance so it isn't touching the TOB and spinning it while running. I have no adjustment on the throw distance of the jeep system either, the bellcrank (linkage) assembly controls that, and is fixed. Subarus don't even have that, and the first shop tried to fix it when I complained about it. All I found on my own was that I can adjust the pedal height with adjustable linkage in the cab at the pedals, but this is not an adjustment of throw distance, or even the clearance setting to keep the fork off the TOB when in gear and clutch engaged, there isn't any adjustment on these like that. But it is nice to lower the pedal a bit so you don't have to lift your heel. If you do this, be careful, it does not take much adjustment to have the clutch engage while the pedal is barely off the floor. I tried some of this setting both high and low to see if it would change the condition, it did not. I share this only because I finally got this issue fixed and found the root cause and thought it relevant in this forum.

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