Notices
Modified JK Tech Tech related bulletin board forum regarding subjects such as suspension, tires & wheels, steering, bumpers, skid plates, drive train, cages, on-board air and other useful modifications that will help improve the performance and protection of your Jeep JK Wrangler (Rubicon, Sahara, Unlimited and X) on the trail.

PLEASE DO NOT START SHOW & TELL TYPE THREADS IN THIS FORUM

Clutch Mod Question

Thread Tools
 
Old 07-30-2020, 04:41 AM
  #1  
JK Newbie
Thread Starter
 
rcharvey71's Avatar
 
Join Date: Jul 2020
Location: Slatington, PA
Posts: 1
Likes: 0
Received 0 Likes on 0 Posts
Default Clutch Mod Question

Hey,
Long time lurker, first time poster here. 2012 JK Rubicon 137K miles. 6 Speed manual. Zero Mods (yet). Mostly highway miles. Never off road. I’m moving to St Thomas USVI in the next few months. Clutch is original, no issues. St Thomas is a very mountainous island with very steep and not so great roads. Some roads are so steep/bad that 4x4 must be used for short periods (1/2 mile at most) on dry surfaces. Thinking it’s best I replace the clutch before I go just because I have the luck that it will fail as soon as I get there and be super expensive to fix on island. Thinking of a heavy duty clutch but have no idea where to start my research. Any advice would be greatly appreciated. This may not be a permanent move so a clutch that will also possibly work on US roads as well would be ideal. Thanks in advance

Last edited by rcharvey71; 07-30-2020 at 04:44 AM. Reason: Forgot info
Old 07-30-2020, 06:53 AM
  #2  
Super Moderator
FJOTM Winner
 
karls10jk's Avatar
 
Join Date: Dec 2010
Location: Knoxville
Posts: 5,642
Received 483 Likes on 440 Posts
Default

There's nothing wrong with a factory clutch. LuK makes good clutches as well (OEM provider for some). Sachs makes your factory clutch, so that likely wouldn't fall into "heavy duty" but works. I'm using a Spec stage 1 (or 1+), and it's not bad. It grabs faster/ harder than the factory one did. It doesn't like a ton of activation though (stop and go traffic) but does great off-road. It just gets super touchy in heavy traffic. I think I'm at 100k on this clutch after putting 120k on the factory clutch. Both have been off-road, seen traffic, pulled trailers heavier than they should have, and run larger tires.
Old 07-30-2020, 06:56 AM
  #3  
JK Junkie
FJOTM Winner
 
Mr.T's Avatar
 
Join Date: Nov 2011
Location: Over the hill
Posts: 2,160
Received 202 Likes on 184 Posts
Default

By coincidence, my next clutch is on the Fedex truck for delivery today. Trying a centerforce II this time, and my plan is to remove the centrifugal weights to lessen the pedal pressure at higher RPM's. Also going with their heavier flywheel because I'm mostly in steep hills, and will be towing as well. This flywheel has a sealed ball bearing rather than the usual roller type pilot bearing which I think will be better, less likely to have grease contaminate the clutch. This obviously isn't a recommendation yet, but what I would recommend is replacing the clutch fork, trans input shaft tube (that the release bearing slides on) and pivot ball along with the clutch + release bearing. The flywheel can be block sanded if it just has normal wear, rather than replaced.
Old 07-30-2020, 07:02 PM
  #4  
Super Moderator
 
Sixty4x4's Avatar
 
Join Date: Dec 2018
Location: Calgary, AB, Canada
Posts: 2,562
Received 470 Likes on 422 Posts
Default

Removing the centrifugal weights can let the clutch slip a little at the higher rpm where the torque builds higher. They are designed to grab more at those higher rpms
Old 07-30-2020, 08:11 PM
  #5  
JK Junkie
FJOTM Winner
 
Mr.T's Avatar
 
Join Date: Nov 2011
Location: Over the hill
Posts: 2,160
Received 202 Likes on 184 Posts
Lightbulb

Originally Posted by Sixty4x4
Removing the centrifugal weights can let the clutch slip a little at the higher rpm where the torque builds higher. They are designed to grab more at those higher rpms
I emailed Centerforce a while ago and the weights contribute to about 10% of the rated torque capacity. This CF2 clutch is rated at 458 lbs-ft, so 458 x .9 = 412 lbs-ft without centrifugal weights. The engine puts out 240 lbs-ft @ 4000 rpm. 412 / 240 = 1.7 , which sounds like a decent safety factor. No plans for forced induction, so it looks good to me. Hate to do it, but my left leg has seen better days.
Old 07-31-2020, 12:11 AM
  #6  
JK Jedi Master
FJOTM Winner

 
Mark Doiron's Avatar
 
Join Date: Mar 2007
Location: Midwest City, OK
Posts: 14,785
Received 361 Likes on 269 Posts
Default

Honestly, the real failure point is the throwout bearing. 268,000 miles on my '07 and never had the clutch itself fail. But have had a couple TOBs that needed replacing, so just did the clutch at the same time. Been running the Centerforce Dual-friction clutch for the past 170,000 miles and do like it. It has a lighter pedal than the OEM clutch. Which works well now that I drive both the JK and a JT, which also has a similarly lighter pedal than the OEM JK clutch. Now, if I could only burn into my brain that reverse gear is on opposite sides of the shift pattern for each of those!

Anyway, back on your question: Yeah, I'd rebuild the clutch in your situation. But wouldn't worry about heavy duty parts. Probably should also replace the rear main seal and maybe even the front seal on the transmission.
Old 07-31-2020, 06:16 AM
  #7  
JK Jedi
FJOTM Winner
 
TheDirtman's Avatar
 
Join Date: Oct 2010
Location: Southwest Reno, NV
Posts: 6,222
Received 363 Likes on 289 Posts
Default

I put the center force on when my first clutch went out. It did not last any longer than the factory one. I also made the mistake of putting on the heavy fly wheel. On my next clutch it will be coming off. The extra weight was not worth the performance gain. Price is also stupid on the center force. Currently running a LuK.
Old 07-31-2020, 05:07 PM
  #8  
JK Junkie
FJOTM Winner
 
Mr.T's Avatar
 
Join Date: Nov 2011
Location: Over the hill
Posts: 2,160
Received 202 Likes on 184 Posts
Default

Originally Posted by TheDirtman
I put the center force on when my first clutch went out. It did not last any longer than the factory one. I also made the mistake of putting on the heavy fly wheel. On my next clutch it will be coming off. The extra weight was not worth the performance gain. Price is also stupid on the center force. Currently running a LuK.
Get what you're saying about the heavy flywheel. Your Jeep has a lot more rotating mass than mine in other places, and it all adds up. I'm in a mood to experiment a bit...


Last edited by Mr.T; 07-31-2020 at 05:11 PM.



Quick Reply: Clutch Mod Question



All times are GMT -8. The time now is 02:59 AM.