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Chris Dobbins

Chris Dobbins

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It has been a little while since I have updated this thread. Thanks for reminding me. I installed the "Centerforce II". Going on 20,000 miles now and it still runs as smooth as day one. Never experienced any chatter or loud noise. This 3.6 engine has a loud valve terrain under 2000rpm with any load, including just the jeep. If you are shifting at 2k then it is bogging the engine. Shift at 3 to 4k to keep your revs up. Pulling any trailers, you need to wind it up a little more to get going. I have 4:10 gears with stock 33s and still wish I had lower gearing in 2wd. Maybe the different material that's in your disc is causing the issue. As you said, our engines really don't produce that much torque. No need for a 450ftlb capable clutch.
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2019JLUR

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It has been a little while since I have updated this thread. Thanks for reminding me. I installed the "Centerforce II". Going on 20,000 miles now and it still runs as smooth as day one. Never experienced any chatter or loud noise. This 3.6 engine has a loud valve terrain under 2000rpm with any load, including just the jeep. If you are shifting at 2k then it is bogging the engine. Shift at 3 to 4k to keep your revs up. Pulling any trailers, you need to wind it up a little more to get going. I have 4:10 gears with stock 33s and still wish I had lower gearing in 2wd. Maybe the different material that's in your disc is causing the issue. As you said, our engines really don't produce that much torque. No need for a 450ftlb capable clutch.
Thanks Chris for the perspective. Totally agree I should have installed the CF II not the DF, I got some bad advise and should have done more research at the beginning. This is the first time I've had a manual Jeep and I guess its just a noisy drivetrain. I think I'm going to see if I can order the CF II friction disc and go from there. Thxs, DJ
 

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Sorry to bump an old thread and write a novel - not sure if its against the rules after 1 year (let me know if there is a new thread)? But wanted to add my experience for anyone still interested, its been a long road for me, I wish I knew then what I know now, hopefully this helps anyone still trying to figure out how to fix what the factory should have never let out the door - and IMO an ECM re-flash is NOT a fix to a mechanical deficiency! ... I upgraded my 19 JLUR to a Centerforce this past April (2021) - with the DF dual friction (KDF157077) and after 5k mi (40-50mi off road/4Lo) its been a love hate experience. @Chris Dobbins , did you get the CF I, II or DF? Compared to stock I love the heavier linear pedal feel and engagement and the heavier flywheel makes off-road starts on steep grades, etc so controllable in 4Lo. BUT for normal street driving... I'm getting chatter in 1st and reverse just as you reach full engagement, CF said to give it 500 miles to break in, but after 5k its no better (or worse). And it's noisy, especially fully engaged driving under load at between 1700-2000 rpm in 2nd or 3rd gear, not grindy, not slipping, not a vibration, not getting better/worse, but a low growl - again I realize that a little more noise is inherent to the singe disc design, centrifugal weights, etc... but I'm always thinking a bearing is about the seize - it's a noise you can't unhear and drives my OCD crazy (my wife doesn't hear it at all LOL). If I were to do it again (to deal with the chatter) I would have gone for the CF I or II , IMO the DF is too much clutch for the underpowered 3.6. I think the only diff between the II & DF is the friction material, so I may end up changing to the II friction disc at some point if they come back in stock . I also would consider a South Bend Clutch, Stage 2 - Daily: KJLW-HD-O. They approach the upgrade differently, they use the OEM flywheel and stock twin disc configuration, but upgrade the friction material on the discs and replace the undersized OEM separator plate (attached to the OEM pressure plate - not sure of exact name) with a custom billet replacement. This undersized OEM mid plate is what I understand is probably the weak link that overheats and breaks apart catastrophically and the reason for the original recall (can't confirm this is fact, but seems plausible) The SB retains the exact stock pedal feel (that's good or bad depending on your opinion of the stock config) with upgraded life, engagement characteristics and heat management. I'm not sure about the SB using the stock vs. heavier CF flywheel in real world conditions - I'd probably choose CF heavier all else equal. Rev hang is another issue - it was a problem when the Jeep was stock and it seems a little worse with the heavier flywheel - especially trying the rock yourself out of a mudhole and moderating the throttle as you get traction, feels like a runnaway train for a few terrifying seconds. (I always wonder if rev hang is an ECM programing thing baked into the software). I'm living with the DF and accept the noise and chatter as minor annoyances becasue the performance is ultimatly great 99% of the time - I may swap the DF friction disc for a CF II disc in the future if my OCD gets the best of me to see if I can possibly reduce the chatter. Hope this helps someone in my shoes a year ago.
I have the dual friction in my 2018. Somewhere around 25,000 miles on it. I relate and agree with much of what you have said. The heavier flywheel is worth it's weight in gold. Our gutless 3.6 now chugs like a diesel down low and you can almost let the clutch out and walk straight up a wall without touching the gas pedal.

There is definitely a rattle below 2500 rpm. It sounds like ping or knock, but my best guess is that it's simply engine harmonics (since it's really not designed to run at such a low rpm) vibrating the weights on the pressure plate.

You are also correct on rev hang, it's programmed into the ECM and the heavier flywheel makes it worse. Livernois has been hard at work on a tune for us manual owners and they've made a lot of progress in controlling the rev hang

It hasn't all been perfect, my Jeep has a motor/transmission misalignment issue (probably responsible for the publicized clutch failures) and it took CF a couple tries to build in slop to accommodate. I'm on a 3rd gen dual friction and it's been great. I highly recommend any of the CF clutches for the heavy flywheel and the drastic drivability improvements that result.
 

sanman357

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Have you tried the relearn procedure for the throttle. It cleared up most of my low rpm valvetrain noise and low speed surging. I am on the stock clutch. It definitely helped.
It has been a little while since I have updated this thread. Thanks for reminding me. I installed the "Centerforce II". Going on 20,000 miles now and it still runs as smooth as day one. Never experienced any chatter or loud noise. This 3.6 engine has a loud valve terrain under 2000rpm with any load, including just the jeep. If you are shifting at 2k then it is bogging the engine. Shift at 3 to 4k to keep your revs up. Pulling any trailers, you need to wind it up a little more to get going. I have 4:10 gears with stock 33s and still wish I had lower gearing in 2wd. Maybe the different material that's in your disc is causing the issue. As you said, our engines really don't produce that much torque. No need for a 450ftlb capable clutch.
 
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Chris Dobbins

Chris Dobbins

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I have not tried that. Will look into it. Frequent oil changes has helped with the valve noise but the low speed "under 7 mph" throttle response is horrendous. The E-throttle can't make up its mind if it wants to be open or closed. :) When in 4 low, this is a nonissue.
 

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GreySportySpice

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Sorry to bump an old thread and write a novel - not sure if its against the rules after 1 year (let me know if there is a new thread)? But wanted to add my experience for anyone still interested, its been a long road for me, I wish I knew then what I know now, hopefully this helps anyone still trying to figure out how to fix what the factory should have never let out the door - and IMO an ECM re-flash is NOT a fix to a mechanical deficiency! ... I upgraded my 19 JLUR to a Centerforce this past April (2021) - with the DF dual friction (KDF157077) and after 5k mi (40-50mi off road/4Lo) its been a love hate experience. @Chris Dobbins , did you get the CF I, II or DF? Compared to stock I love the heavier linear pedal feel and engagement and the heavier flywheel makes off-road starts on steep grades, etc so controllable in 4Lo. BUT for normal street driving... I'm getting chatter in 1st and reverse just as you reach full engagement, CF said to give it 500 miles to break in, but after 5k its no better (or worse). And it's noisy, especially fully engaged driving under load at between 1700-2000 rpm in 2nd or 3rd gear, not grindy, not slipping, not a vibration, not getting better/worse, but a low growl - again I realize that a little more noise is inherent to the singe disc design, centrifugal weights, etc... but I'm always thinking a bearing is about the seize - it's a noise you can't unhear and drives my OCD crazy (my wife doesn't hear it at all LOL). If I were to do it again (to deal with the chatter) I would have gone for the CF I or II , IMO the DF is too much clutch for the underpowered 3.6. I think the only diff between the II & DF is the friction material, so I may end up changing to the II friction disc at some point if they come back in stock . I also would consider a South Bend Clutch, Stage 2 - Daily: KJLW-HD-O. They approach the upgrade differently, they use the OEM flywheel and stock twin disc configuration, but upgrade the friction material on the discs and replace the undersized OEM separator plate (attached to the OEM pressure plate - not sure of exact name) with a custom billet replacement. This undersized OEM mid plate is what I understand is probably the weak link that overheats and breaks apart catastrophically and the reason for the original recall (can't confirm this is fact, but seems plausible) The SB retains the exact stock pedal feel (that's good or bad depending on your opinion of the stock config) with upgraded life, engagement characteristics and heat management. I'm not sure about the SB using the stock vs. heavier CF flywheel in real world conditions - I'd probably choose CF heavier all else equal. Rev hang is another issue - it was a problem when the Jeep was stock and it seems a little worse with the heavier flywheel - especially trying the rock yourself out of a mudhole and moderating the throttle as you get traction, feels like a runnaway train for a few terrifying seconds. (I always wonder if rev hang is an ECM programing thing baked into the software). I'm living with the DF and accept the noise and chatter as minor annoyances becasue the performance is ultimatly great 99% of the time - I may swap the DF friction disc for a CF II disc in the future if my OCD gets the best of me to see if I can possibly reduce the chatter. Hope this helps someone in my shoes a year ago.
I like your write up. If it makes you feel better rev hang IS programmed into the ECU. It is done for emissions as closing the throttle body quickly to drop RPM will lean out the engine and anything not stoichiometric produces more emissions. You could probably tune it out.
 

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My clutch engagement is fine...my issue is in the shifting. If I park it in 1st gear and let it sit and then start it up and try to shift out of first it takes effort, even if just moving to neutral. At times I'll hear a faint, low frequency hum as well. Less frequently, but not rare at all, it will stick trying to go into gear. Some of this may be the factory 'slop' Toy speaks of.

I need to find out what CF clutch I have (on 3rd one and they were shipped direct to installer). I understand there is a newer variant out. Mine was installed spring of 2020.
 

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My clutch engagement is fine...my issue is in the shifting. If I park it in 1st gear and let it sit and then start it up and try to shift out of first it takes effort, even if just moving to neutral. At times I'll hear a faint, low frequency hum as well. Less frequently, but not rare at all, it will stick trying to go into gear. Some of this may be the factory 'slop' Toy speaks of.

I need to find out what CF clutch I have (on 3rd one and they were shipped direct to installer). I understand there is a newer variant out. Mine was installed spring of 2020.
You may be able to alleviate much of this by purging the clutch hydraulics. What seems to be the only way to accomplish this is to remove the slave cylinder from the transmission, carefully push the plunger straight in all the way several times to force the fluid (and air) back up to the reservoir. Then carefully re-insert to the transmission. When hitting the clutch pedal the first time, if it's gets really hard, you probably missed the clutch fork. Don't press harder or you will blow the slave cylinder apart (i've done that twice ?‍♂). Go back, remove the slave cylinder and re-insert, try again.

Most likely the sticking will be resolved after purging the hydraulics
 

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When you are at a complete stop and cannot get into first gear you should shift into 4th gear and then it will let you shift into first.

You are welcome
 

Willing&Able

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When you are at a complete stop and cannot get into first gear you should shift into 4th gear and then it will let you shift into first.

You are welcome
Yeah, because that is functioning properly. For $1k clutch and more for install I don’t want to have a decoder ring to get into gear.
 

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vasil

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Yeah, because that is functioning properly. For $1k clutch and more for install I don’t want to have a decoder ring to get into gear.
I had my clutch for almost 1 year and it's been working perfectly.

244764734_4860682500649903_66318422661900256_n.jpg
 

Willing&Able

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I had my clutch for almost 1 year and it's been working perfectly.

Jeep Wrangler JL Centerforce Clutch Installed on JL Rubicon 244764734_4860682500649903_66318422661900256_n
Yes, after you had to have it trailered to CF (not just due to clutch to be fair), had noise/grind issues, had several versions installed, etc. Love you bro, but we both had a year of challenges with these clutches. I know yours is perfect now, mine - and others - are still not. Unfortunately I don't live close to CF so it is a huge pain anytime I need a fix...
 

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You can bleed the clutch hydraulics without pulling the slave cylinder.

- Back the jeep up on some ramps. Make sure the rear is high enough that the back of the slave cylinder is pointing uphill.
- Now push the clutch pedal in by hand and wedge something to keep in pressed down.
- Climb under and slowly open the bleed "screw". The bleeder is a plastic valve that can be turned by hand, no wrench required. Like I said, open it slowly, it is going to make a mess.
- Once it has finished spraying brake fluid all over, close the valve.
- Now pull the prop out that you used to hold down the pedal. The pedal is going to stay on the floor. Pull it back up slowly.
- Rinse and repeat until you are satisfied that the system is bled.

You cannot bleed the system using a Mityvac or pressure pot. Jeep brought the supply line to the slave cylinder in at the same spot as the bleeder valve. Really a dumb design. If you try either of these two methods, the fluid will just bypass the slave cylinder and go right out the bleeder.

Pete
 

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1st thing: Chris don’t apologize for reopening this thread as your post is extremely valuable.
I’m still on my original clutch (26k)and have been avoiding the dealership to not get that engine detune.
When my time comes I was all in on a Centerforce clutch but am now getting a little scared. I can tolerate a little noise but not vibration or worse having to jam the trans into gear.
These last posts have me thinking of maybe just going OEM when it’s time.
Oldguynewjeep posted another brand not to far back. (Southbend clutch) Does anyone have reviews for that brand?
 

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Again, there is no engine detune. It has exactly the same power, feel,, and performance as before the flash. It's just a safety feature that only kicks in under extreme conditions.

This has to be the most misunderstood recall I've seen, and I blame Jeep for not properly explaining it. But the engine has full power unless there is an excessive amount of slipping detected. Enough to cause an overheated clutch. Only abuse or a problem would cause it to go into what should have been described as a limp-home mode.

I have not yet seen one person on the forum experience it. Even I didn't experience it when teaching 3 of my kids to drive a stick. The only thing I experienced even then was heartburn.
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