JL 3.6 Manual Transmission Clutch.... Please ELI5

[Toycrusher]

Half doors might be second favorite thing in the world. Forgot what the first was...

Affirmative, I am on the OEM KO2's.

Confirming what Maverick had to say.

Gearing multiplies the force of the engine. 3.45s were an absolutely ridiculous decision by Jeep. I imagine 4.88s are perfect with stock size tires. I'm on 37s and planning to go 5.13 or 5.33 to get a similar effective ratio to what you are enjoying right now.

The Centerforce high-mass flywheel has a big advantage over the stock featherweight flywheel when it comes to getting your Jeep moving. In the simplest terms, it takes more fuel for your engine to start spinning, but that extra energy put in is retained within the flywheel. when you let out the clutch abruptly, that energy is transferred to the wheels getting you moving without requiring you to add fuel through additional throttle or to waste energy through excessive clutch slippage.

Why didn't Jeep use a heavy flywheel to start?

Because Govt mandated start/stop system, and a heavy flywheel wastes fuel when using start/stop...

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[Maverick909]

If the nose is pointed down at all I tend to start in 2nd. Works like a charm. I will be curious to see what you think about the 4.88's once in. If you don't mind me asking, all-in, how much is the swap going to cost you?

I was able to get the master install kit from Yukon for $875. Install cost as of right now is $1200 but that included installing the Dynatrac Rebuildable HD ball joints, alignment, and installing the gear kit. Cant wait to drop it off Monday. I am super excited to see how it drives after the re-gear

 

[Maverick909]

If the nose is pointed down at all I tend to start in 2nd. Works like a charm. I will be curious to see what you think about the 4.88's once in. If you don't mind me asking, all-in, how much is the swap going to cost you?

I was able to get the master install kit from Yukon for under a grand shipped

Confirming what Maverick had to say.

Gearing multiplies the force of the engine. 3.45s were an absolutely ridiculous decision by Jeep. I imagine 4.88s are perfect with stock size tires. I'm on 37s and planning to go 5.13 or 5.33 to get a similar effective ratio to what you are enjoying right now.

The Centerforce high-mass flywheel has a big advantage over the stock featherweight flywheel when it comes to getting your Jeep moving. In the simplest terms, it takes more fuel for your engine to start spinning, but that extra energy put in is retained within the flywheel. when you let out the clutch abruptly, that energy is transferred to the wheels getting you moving without requiring you to add fuel through additional throttle or to waste energy through excessive clutch slippage.

Why didn't Jeep use a heavy flywheel to start?

Because Govt mandated start/stop system, and a heavy flywheel wastes fuel when using start/stop...

Great explenation of the flywheel size. I hadnt even thought about the start stop system having an effect on the sizing. i havent used the start stop but a handful of times since buying my jeep.

 

[Rubi6mt]

I have the factory 4.88's on the stock wheels and tires and I am curious about your statement here. I am trying to learn as much as I can about driving a manual well.

You said that you can "bring up the clutch h with no gas and idle it along at 3-5mph in stop and go, something the stocker would not do."

If I get into 1st, no gas, just clutch like you said, It doesn't take but a momentary release and it idles on flat ground at 2mph. It starts laboring below that (uphill below 2). Is this normal? Is it because I have the 4.88's that mine idles slower and has not had a problem using just clutch to get it moving into 1st?

Listen, I am no offroad/Jeep guru and I ordered the 4.88's because I liked the idea of going slow on trail and it has preformed beautifully for that. Now I want to understand everything that entails.

You can essentially bring up the gas pedal at idle in any manual equipped vehicle to get it going on a flat surface, its more a matter of how much clutch slip you are willing to tolerate. What makes the it so easy now in my setup is the heavier flywheel of the CFII clutch kit providing much greater inertia. It literally feels like I have an extra 50lbs/ft of torque at idle. In stop and go I essentially just use the clutch pedal and brakes, no gas. My build is not the lightest either with full AEV setup including 10k winch.

Of all the mods I have done, i think the CFII clutch kit is my favorite for drivability.

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