Hey ya'll. As some of you read, I am having my trans rebuilt by Tick. I purchased the tick ls7 clutch kit, but as some have pointed out, that's a bit overkill for a stock car. So I'm looking at getting just a stock clutch replacement, and from what I've read LuK made/makes the stock oem clutches. I have found a few different ones.

From what I've gathered, LuK part number 04-173 is stock? It says it works for all the vette's as well as trans am's, camaros, etc. Is this the one I'm looking for?

I'm not sure what part number this one is, it doesn't say. But it's the most expensive one out of all of them and I'm pretty sure this is just someone selling the 04-173 at a more expensive price, but I could be wrong.

LuK part number 04-905 is the ls7 clutch and flywheel, etc. While, this will work, I'm told you need to get a new adjustable master cylinder on top of this, as well as needing to do the air gap when installing. If this is correct, please let me know.

If anyone has recently installed a LuK clutch, please let me know how you like it and which part number you purchased, as I think the stock ls6/z06 replacement is 04-173, while the ls7 is 04-905.

Next question would be, is the ls7 clutch worth it? I say worth it, but the 04-905 is cheaper than 04-173, so for a stock c5, what would ya'll purchase and why? Keep in mind, car has 148k, is my daily driver, and I'm installing a tick stage 1 trans at the same time. Thanks ya'll!

 

I started a thread on this a month ago check my post. Good company and I'm going with them when the time comes. Search my old thread

 

I saw your post and I agree. Good company. My question though is which kit is which kit is better for my situation. I just need a good clutch. Obvs if there's not a huge price difference I'm down to upgrade. So here's what I've narrowed it down to. The tick ls7 clutch package(I opted for aluminum flywheel) I purchased was $1,154.97. If you were to buy everything in that package separately, it comes to $1,554.41. Huge savings. Now, if I were to get the Z06 LuK 04-173 kit, with everything needed to do the clutch, it would be $724.45. If I were to get the LS7 LuK 04-905 kit, with everything needed to do the clutch, it would be $840.22. That's without aluminum flywheel. The tick package is a huge savings bundle. However, for people just running a stock corvette, I think the z06 package would be just fine. It's also $430.52 cheaper. So my question is, is the ls7 clutch upgrade really worth it? I feel like I'm not going to notice it on my car. I don't do burnouts, I don't drag race, I don't time lapse or auto cross, I just daily it. Yes, occasionally I'll put my foot down but I'm careful with it. I don't let it redline, I shift way early. (If it wasn't my daily, maybe I'd be more harsh on her). So what do y'all think?

 

IMO it's always better to have more than you need instead of sitting on the side of the road wishing you had gotten something a little better.

I use to run LUK clutches in all of my NASCAR Weekly Series Street Stock Cars that I ran here in the Northeast before buying my C5Z... Never ever had one fail. Great clutches!

Side question though for my own build/curiosity? How much can the LS7 clutch handle? Anyone know?

 

i just put in the 04-905. about $240 on amazon. no modifications needed. stock replacement hydraulics. works great. got about 270 miles one it. putting down about 450hp to the ground.

 

Brought back fond memories of shopping for parts for the old 911 on Pelican. LuK makes good stuff.

 

How was the air gap measurement? You didn't need the adjustable master?

 

that measurement is excessive and unnecessary. i've never done it. never had any problems with the 30+ clutches ive installed.

no. not adjustable.

 

The FSM calls out a measurement, but it is with the clutch pedal fully disengaged. So you have to have the car together, an assistant in the car to push the pedal and someone underneath to measure the gap. the FSM does no call out a dimension or tolerance, so I'm guessing it is to make sure the clutch disc will spin freely between FW and PP when the clutch is disengaged. I'm with HPS, never taken that measurement never needed to.

There should be no need to shim anything if all parts are OEM dimensions. there is a spring on the slave that holds the throwout bearing in light contact with the PP fingers. There is some takeup of this spring to compensate for disc wear. That way you never have any adjustments to make like you did in the old days, and no "freeplay" considerations.

The adjustable master cylinders are to match the volume of hydraulic fluid provided by the master from full mechanical travel of the pedal to the volume needed by the slave to produce full travel of the PP to engage and disengage. Undermatch and the clutch does not fully disengage, overmatch and the pedal gets really stiff near the floor because you are over compressing the PP and it takes more force.

Luckily, the OEM master matches the needed volume. The only time an adjustable master would be an advantage is if you put an aftermarket clutch in that responded differently than an OEM.

Here are some fotos of a C5 slave.

 

From searches I did before installing my LS7 clutch, the general consensus was between 550 and 600 RWHP. It depended also on whether you were tracking the car or just mostly street driven. The thought process was that if you were spinning street tires, and not hooking, there was less load on the clutch and it could take a few more ponies before having issues.

 

VERY interesting...

My plan for my car is just P&P LS6 heads, Fast 92 intake and Vindicator Cam... No power adders. It's mainly a street car that will see some 1/2 mile events and maybe a couple trips to the drag strip or road course/autocross (on street tires)... I may have to look into this as an option for a clutch to keep decent street drivability. I really can't see the car making more than 500rwhp if it even makes that much at all. Thanks for the info!

 

Hmm, so even though the LS7 clutch is meant for a much newer car, due to it being oem, I won't need to do the measurement? I understand if it's just a LS1/LS6/Z06 straight replacement clutch, that makes sense as it's the same clutch but new. However, if one were to install the LS7 clutch, would it matter?


HPS Master Tech, you said you just installed the 04-905. That is the LS7 clutch right? How do you like it? Did you have a stock clutch prior? Is it heavier as everyone says? Did you go with the aluminum flywheel or stick with steel? If I can just buy this kit, and not need anything else (I'll still replace pilot bearing, slave cylinder, maybe master cylinder if necessary, and install the remote bleeder), then I think I will return the LS7 clutch kit I purchased from Tick and just get this. Again, much much cheaper than that kit.

 

The friction area is larger on a LS7 and I think It has greater spring force to hold the disc against the flywheel, so unless the flywheel weight is reduced, it will be a bit heavier. Not sure about the assembled dimension, I've only put 3 ls7's in,one in my Caddy CTS-v and two in C6Z's Never measured anything B/C we always put back OEM (C6/LS7 slaves)slaves. I think they might be the same stack-up dimension, just not sure. I am pretty sure the splines are the same as the Tremec Tranny that has been in Corvettes for a while now.

Now in one of your posts you mentioned aluminum flywheel. That changes stuff. At that point you will need to be talking to the supplier about shims or not to get the slave at the right position WRT the clutch.

One thing I have never done is put a LS7/C6 slave in a C5, but the position and configuration of the hydraulic connections, both to the master and the bleeder are different, and you would have to do some bellhousing cutting. The later edition slaves may also have a different stack height. Last one I had in my hand was leaking so to the trash it went.

 

I am currently at just over 400 RWHP/ 385 RWTQ with a 224R@114LSA cam, RHS as cast heads at 11:1CR, LS6 manifold and XS-Power LT's through Ti Z06 exhausts. It is an LS7 clutch and steel fly wheel with new slave and throw-out bearings and a Tick adjustable master cylinder. The Tick master though gives it a very short engagement travel so it took some getting used to. But it is very driveable with what seems no more pressure than the stock clutch. It has performed without issue even when I engage the Nitrous on occasion which brings it to 543 RWHP/ 617 RWTQ. I have plans for a A&A supercharger but plan to keep it boosted to about 500-550 RWHP and think the LS7 should do OK. If I don't do the SC I may have the heads ported by Advanced Induction to see if I can bring the NA RWHP into the 440-450 range without the spray. Clutch should still be OK if I don't beat on it to often.

 

the 04-905 just looks like the ls7 clutch. i used everything it came with. it is made to be installed in a c5. yes stock clutch prior. just alittle heavier than stock. you can't notice a difference after a few days of driving. i didn't need to shim the slave.
on my ta i used to have i installed a real ls7 clutch and needed to shim the slave

 

the only measurement a do is the installed height. this would let you know if you need to shim your slave.
just some prospective. a credit card is about .030 thick.

 

Oh, ok cool. How do you measure the installed height? Do you actually go through and bolt the pressure plate to the flywheel with the clutch and everything? These pictures are the pics of the stock clutch compared to the new 04-905 clutch? Like I said before, I've never done a clutch on any car. So any advice is helpful. Hearing you say that you've installed the 04-905 without doing anything else is awesome. Makes me feel a lot better. Definitely going to return that clutch package then.

 

yep. bolt it together and sit it on something flat. don't need to worry about the thickness of whatever you set on the levers your just looking for the difference between the 2 clutch sets. yep. these are my pics. my stock clutch had 150k miles on it. it still worked good. i pulled the engine for a rebuilt so it was time to change it.

 

Ok, awesome. My clutch is right around your mileage as well, so I'm thinking the same thing since I'm replacing the torque tube and trans. So I should probably replace the clutch too. So the difference you measured doesn't matter at all? It's kinda hard to see where the decimal is and whether you're in inches or cm.


I apologize for all the questions, I just can't afford to have the car down for too long. You said you don't notice it being that much heavier? How is shifting? I'm still debating on whether or not I should get the aluminum flywheel. If you had to do it again, would you?


Again, thank you all for your patience.

 

Very interested in this thread. OP, your situation is like mine. Got my finger on the trigger for the 04 905 from Rock Auto, $225+ shipping. http://www.rockauto.com/en/catalog/c...lutch+kit,1993
Don't drag race much any more. Kooks LT, CAI, and a tune. 331/356 at the wheels. 210k+ miles so looking to rebuild the TT also.

WHAT'S A GOOD REASONABLY PRICED SLAVE??

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