Problem
For a while now I have had to raise the rpms so I wouldn't get the forward lurch of my driveline pushing my 32 inch tires on a 3rz/4.30 elocker gearing. Even with an upgraded pressure plate that had plenty of grabbing force, there simple wasn't enough inertia in the driveline to smoothy shift and keep the larger tires rolling. I could continue to raise the rpms while shifting but that is hard on the clutch mechanism.

Quality
So I went ahead and bit the bullet on a the $350 35 lb flywheel from LCE. The machining quality (only required a .5 gram balance) was top notch over the casted aftermarket flywheel I had on previously. Even the starter teeth were machined better and reduce the extra noise I experienced on ignition from behind the firewall.

Driving Experience
Shifting is a lot more pleasurable compared to looking for the narrow powerband range I had to keep to before. I haven't noticed any significant slowing (5speed may account for that) and can still reach peak rpm fast enough for my uses. So if you are afraid of it dogging down your engine, don't be. I have to still see if there is any MPG difference but with gas around $3, I'm not worried about it. While I was replacing it I also got the Aisin/Seco 1200lb Clutch kit from Marlin Crawler. I would agree that the SECO disk seems to handle the shock load better than my aisin disk. Overall the combo has lead to a much better driving experience.

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Hi Wikano,

I own a similar model 4runner with 3rz and 5spd. I love this 'little' rig.
I installed and LCE high torque flywheel about 2 years ago for the same reasons you stated. I also installed a Marlin Crawler clutch disk at the same time. On the trail (only, never on street) the clutch would occasionaly slip when under stress. Like starting from stop on an obstacle or steep hill. So, I bought a LCE Pro Clutch disk about a year ago and installed it, and no more clutch slipping. The pedal feel (to me) is a little stiffer (harder), but not unbearable. I hope you have good luck with your MC clutch disk, I just wanted to share my experience, in case at some point it may be helpful. Also, to say I agree with your comments on the high torque flywheel.

BTW, I'm on 35's, which are obviously harder to get rolling.

3RZ's are awesome!

Durwin

Hey guys, this is interesting info. I was always wary of heavier flywheels but hearing your feedback makes me want to think about it again. I've also got the 3RZ with a 4.56's and 32's.

Sounds like a heavier flywheel could help with smoothing out the off-the-line start and shifting.

Jordan, I was hesitant at first too, but I am happy with the slight performance improvement it afforded.
First, there are several hills on the roads near me that I would usually have to downshift near the top to keep my speed up, since installing the LCE flywheel, I no longer have to downshift.
Second, on the trail, I am able to lug the engine down to 600-700 rpm and not stall it. This is handy at times.

It made my 4runner more 'fun' to drive....if that makes sense.

Good luck

Durwin

One of the first things I noticed was that the MC clutch did not feel like my previous 1200lb clutch. I wouldn't have been surprised if someone said they accidentally replaced it with the stock 900lb clutch. While I haven't pushed it too hard yet to test that claim, the pedal feel was very light even though the clutch line is bled out. I wish I had the foresight to see if the model numbers matched up with my previous heavy duty clutch (which still worked great).

*************HOLD UP. WAIT A MINUTE***************

I have my old 1200lb clutch (Aisin CTX-107) and the Marlin Crawler Pressure plate box with a .... dun dun dunnnnnnnnnnn CTX-106 pressure plate. They sold me the 900 lb clutch when I ordered the 1200 lb clutch. Perhaps it's a mistake but I hope they haven't been doing this for a while. I have had 3 clutches: CTX-106 amazon 2015, CTX-107 "1200lb" Ebay 2017, and the Marlin Crawler CTX-106 with Seco disc in 2020. My first replacement clutch, I had the same problems you did with steep inclines, though I thought the clutch pad may have been contaminated. The 1200lb clutch was a dream and did a great job holding up. Looks like I'll have to put my old 1200 lb clutch on the next time I drop the transmission.

I guess I'll have to give Marlin a call...

If you guys have flywheels around do you mind sending me some basic measurements? OD, ID of the main step, thickness, etc? I want to do some math to determine how much more HP it takes to simply spin the flywheel from 1000-3000rpm.

Not being a driveline engineer I had to make some assumptions and if anyone wants to check my work be my guest...

Assuming 10" OD, 5" ID of thick part of the flywheel. Question is how much HP does it take to rev a flywheel from 1000rpm to 3000rpm in a certain amount of time.

Stock 24# flywheel: 31HP for 3s, 9.5HP for 10s
Heavy 35# flywheel: 46HP for 3s, 13.7HP for 10s

So the power it takes to rev it scales linearly with the weight of the flywheel. I kind of thought that's how it would work out but wanted to do the math to confirm.

In looking at your picture of the two clutch discs, the one on the left has more disc area available for grabbing the flywheel, if that makes a difference, which it should.
There are 16 "cuts" in it vs. 25 in the other, plus one on the right has the odd circular cut in it reducing surface area even more.

In the very rare chance JZiggy that you are still looking for one. I have one I’m looking to sell. I was given it and it doesn’t fit my engine.

Sure, tell me more. Looks like we can't PM since you're a new member.