Kevlar Clutch........What's your view?

Well,here's the deal.I have been looking for a good performance clutch that will handle the stress that off-roading/rock krawling does to a clutch set and the heat build up that is generated by constant slippage in the rocks and the like.I have been looking at Spec clutches and the dual friction one from Centerforce.The Spec one is a Kevlar faced clutch disc designed for heat loading.Further searching lead me to ZOOM Clutches,which also makes a performance clutch.I noticed that the company is 3 exits from my current work place here in Charlotte,NC.I contacted them directly on the phone to see if they sold publicly,they do not, I spoke with a product engineer there and was told they are producing a clutch kit for jeeps,get this,it will consist of a CRYOGENIC proccesed flywheel,CRYOGENIC performance pressure plate,and a pure 100 % Kevlar disc,wait it gets better-well for me anyways-Uppon further conversation with him,Chris,he mentioned that he may be able to give one away for testing,that was yesterday.I went there today to visit the facility and after talking with the operations manager he came out and looked at my XJ and is giving me a kit to test for them!!!! SAAAAWWWEEETTTTT!!! They have designed it specifically for jeep applications that see high slippage and heat build up,hence the CRYO proccess.I think this is really excellent of them to come up with such a product for us hardcore,diehard manual trans jeepers.Of course I will need to provide them with technical data and testing results as there goal is to mantain a steetable,high abuse clutch kit.Sounds like they are on to some new inovative ideas.What do you guys/gals think of this kind of clutch set up? any questions or comments on what I really need to do to help with the testing procees?The kits are not even on there site yet,actually when i went there they were packaging these units,pretty impressive high quality stuff.

From what I have seen with the 'hardcore' manual trans guys, the stock clutch seems to be more than sufficiant.

I helped a guy swap out his original factory ax15 clutch here a couple weeks ago, he had 254,000 miles on it, and wheels like a mofo.

The cryogenic process is done to normalise the castings that make up the outer friction surfaces, and to relieve (or eliminate) any internal stresses that will be produced with heat - so that's a good thing.

Kevlar/aramid fibres are something I've only worked with in cordage, but their heat resistance should help with clutches greatly. I doubt the "self-abrasion" seen in aramid ropes will be a problem - since there's no relative movement between fibres in a clutch as there would be in a rope running through a deceleration system (like on a rappelling rig.)

I've been considering having an aramid clutch wound by a local shop here (who also does them - Robin Yates at Superior Friction, North 10th Street, San Jose,) but I haven't gotten that far ahead yet.

I would appreciate a copy of the report you submit to the outfit after your test & evaluation - for my own interest, if nothing else. I think the aramid clutch will do quite well - especially in situations that are likely to heat up the clutch (that we often find ourselves in - climbing, crawling, towing, ...)

Stock. I thought about a 'racing' type one, but with good gearing slipping/burning of the clutch isn't a problem.

Absolutely 5-90 I will be doing that,I do believe my photos and test results are going to be posted on there website,www.zoomclutch.com as well ,but I will let you know how this unit is holding up.There goal is a streetable unit that can take heavy abuse.My XJ see's Daily Driver and it goes to the Uwharrie Forest here in NC and now it will be going to go through testing at Tellico here on the East coast.Believe me I will be slipping the hell out of this unit and try to abuse the hell out of it,especially at Tellico,There is of course a small breakin milage needed for a Kevlar unit,under 400 miles.Cool,very cool.Gotta love real world testing,it makes positive results, and somebody that desides to by something or not just cause "some one else" says so........:twak: or not.

Sounds good.

I've rarely allowed clutches to go over 100K - I'll replace them at that point just as preventative maintenance (they're usually better than half-good still, but it makes me feel better.)

Do be sure to follow whatever break-in procedure they give you for it - I've not got any direct experience with aramid clutches, but reports from the field show that proper break-in is potentially more important for aramid clutches than for standard jobs.

Once it's properly broken in, tho, it should be perfectly streetable as well as handling heat from off-road and towing handily.

Yes, you're going to get your share of naysayers - but I've been wanting to evaluate one for some time now (if I didn't end up running it in a DD, it would be more a matter of preference than anything else - but I think myself a "spirited" driver, and I've had no trouble putting 100Kmiles on a clutch. I don't know how much farther I'd go, since I cut them off ~100Kmiles anyhow.)

So, RSSorM, I'd really like to hear about your experience with aramid-fibre clutches.

If you think a stock clutch lasts long ,check here-------http://www.zoomclutch.com/hp_series.html

5-90 I was told how the breakin procces is going to lay out...quite easy really,I was told that for @ 300 miles or so it will have a tendency to slip and all you have to do is just let off of the throttle thats it,of course that will be normal street driving no off roading,the kavlar needs to go through heat application and then coolling not like a new set of gears that need to cool of completly,just let off the gas when it does,I talked to them for about and hour or so,and they had a peson with a dodge dually diesel that tows a huge horse trailer that had a clutch installed and could not let off when he was towing so he kept slipping it by load not by actually using the clutch pedal.so that is basically it.The operations manager told me most of there returns under warrany had been glazed over simply by not letting it break in properly,they do alot of HP stuff like you know stangs and chevy stuff.I am going to go that route just let off the throttle when/IF it starts to slip,they could not stress how important it is to really do this breakin period.

Hey Free is Free:thumbup: Are they doing the install for you too? I have to agree with what people are saying about the stock clutch. Pulled mine at 167,000 (due to internal slave) & still had about 50% left on the disk. I opted for a Luk Gold which has been nice, but not really tested by me yet.

Good luck with the testing

Rob

Where in Charlotte is this place located at? I am interested in getting a new clutch to handle the power of my 4.6L stroker and still spin some 35s. So far the factory clutch has been fine and has lasted 20k miles or so behind a built 4.0L motor and another 20 behind the stroker but the last time I went out drag racing it started to not be so happy and slipped on my last run against my suitemate's honda prelude. Still beat him, but the little bit of slippage has me concerned And if a 275hp 4.6L stroker on 35s drag racing isnt hard on a clutch, I dont know what is

AARON

Ok here is some photos of the actual clutch-flywheel-pressure plate I was supplied with.
New Flywheel

New Pressure Plate

New Kevlar Disc

The install was just like a standard clutch/flywheel install no issue,fit was perfect.What the kit cosists of is a 100% Kevlar disc,New Cryongenic proceesed flywheel,New Cryongenic proceesed pressure plate,New Clutch release bearing,New needle bearing pilot bushing,install tool.I finished the install on Sunday the 17th.When I first engaged -or disenged to be "corect"-the clutch it was VERY smooth,actually easier pedal pressure than the LUK I had in there-well as you know when a new clutch is installed it WILL have an easier pedal at first because they are designed that way and as the clutch wears in the pedal effort will increase slitghtly to maintain even clutch disc holding ability.I eased on the throttle at around 2500 rpm's while on the hiway @ 70 mph,the clutch did start to slip for around 100-200 rpm's for about 1 second as thats when i let off the gas.I tried this at 25 miles of driving so I did not try it again as I did not want to glaze it over.I then drove the rest of the way home-60 miles total-with out trying to accelerate quickly again-normal driving.On Monday I drove to work as usual - normal easy acceleration,well for now,I was around the 100 mile mark on the hiway at 2500 rpm but in 4th gear at 55 mph and tried to throttle up,started slipping same as before so I let off the gas and drove normal-fine at this point.I drove for the next 2 days normal not trying to hit the throttl eheavy ,all is fine no slippage nor did I try.On Wednesday I visited the ZOOM shop and talked with the product and had him drive my jeep to see how it went.He noticed it was very smooth engagement as well no chatter or harsh engagement at all,I had the same results allways smooth and no quick engagement or loss of peadl hight or effort.He told me that what I was doing was fine in fact he sais that when I start out slip it more than I usually do to help burnish the disc in.He at that point hit the throttle and it slipped only about 50-100 rpm's all is good,as I told him when and what I do with it.On thursday I was on the way home on a side road not the hiway in 4th gear at 55 mph,2500 rpm's and hit the gas no slippage was present.I increaed the throttle for some quick acceleration ,slipped for about 50 rpm's not much anymore,this was around the 400 mile mark.Today I tried some heavy acceleration almost full throttle on the hiway at 75 mph,2600 rpm's in 5th gear no slippage,500 mile mark.I am going to try it again today at lunch when the jeep is cold and see if it slips,and try it when it is hot to see if it has any thing to to with temp.It however seems to have done the slippage at first when it was hot or thats when i tried it.I believe it is prety much broken in I am not going to try to wheel it and use it i nthe rocks until about the 700 mile mark just to be safe.I was told that the way it gets glazed over is from constant hi rpm slippage and not letting off the gas,and what i had done to it was actually and excellent breakin procedure.Slipping it on take off and now and then with slight slippage for a second or 2 .I will add that I am really liking the way it acts and engages and drives.I have some more photos at photo bucket and I will provide some results latter today.so for now here are the photos and please i you have any requests for what you woud like me to try with it and how I'm game.................
http://s187.photobucket.com/albums/x302/markaboo929/

Re: Kevlar Clutch........I have upgated my original post

sorry though it was a new thread.

Got any pics from the actual install?

yup I have them on my photobucket page ,but here ya go.I only took photos of it on the back of the motor,not as the trans is going in,that's strandard replacement.
Flywheel in place

Clutch disc in place

Pressure plate and assembly on

Trans in place with TNT Long Arm crossmember

My JEEP

One of the main issues I wanted to avoid was heat build up-and the cryogenic freeze process deals with that,You can see in this photo of my old clutch disc heat was present on the hub section.I do not ride my clutch or slip it hardly,so when I wanted to replace it I was looking for a kevlar type-I just happened to be graced with a test unit that was cryo frozen to boot!!
Old Disc-stock luk
this one has 75,000 miles on it

How much more would the retail cost be on one of these kevlar kits than a standard clutch kit?

For comparison, I can get an OEM clutch kit with disc, pressure plate, throwout bearing, and a new slave cylinder for $200 or less.

Also, in the picture above...aside from some bluing, what's wrong with that disc? The surface looks like it has plenty of life left. IMO, if you're getting enough heat buildup to the point where temperature becomes that big of an issue, you either need to learn how to drive stick better or re-evaluate the way your rig is set up. If you're worried about having to slip the disc frequently off-road or in the rocks, then your gearing sucks. If you have to slip the clutch off the line to get the truck moving without bogging or stalling when driving in traffic, then your gearing sucks too.

Just for reference, I replaced my stock clutch at 120k miles because I was replacing the transmission at the time, and the friction surface was just starting to show some wear (I wasn't the original owner either). I also did a quick resurface on the flywheel. I replaced the clutch again at 175k because I was doing a massive drivetrain swap with an NV4500 and doubler box, and I kept those pieces as spares because there wasn't anything really wrong with them. Each time I've just used regular OEM replacement parts and I've had no problems. The clutch never slips itself on the highway even during break-in and once I got my gearing straightened out I didn't burn it at all on the trail either.

In a case where there have been significant motor upgrades done, then yeah, I can see a need for something like this. But if I can get 100k+ miles out of a $180 OEM clutch kit and have no complaints with it, then I'm definitely not going to want to pay much more than that for a benefit I'll never see.

http://www.apparelsearch.com/Definitions/Fiber/kevlar_fiber_definition.htm
here ya go
http://www.virtualsciencefair.org/2004/clar4c0/public_html/en/properties.htmlhttp://composite.about.com/gi/dynamic/offsite.htm?site=http://www.dupont.com/afs/kapplications.htm

did that last post make sense to anyone? Cuz it just seemed to ramble on and go nowhere to me..

can you relate stress and heat to what offroading does? then it makes sence.....to me anyways...........thats why I am me and not you:spin3: