turbotuner20v

I'm having an issue where my RXT clutch appears to be preloaded and is damaging my throw out bearings
(http://forums.corvetteforum.com/c6-f...5-preload.html)

I'm trying to sort it out with McLeod, but we're both a little confused about why it's preloaded.

They gave me the following measurements:
Extension of crankshaft past engine block/bell housing flange - 0.330"
Flywheel thickness - 0.880"
Clutch assembly thickness - 2.100"
Bell housing flange to flange - 6.440"

So .330 + .880 + 2.100 = 3.31" . This is how far the clutch assembly pokes out into the bell housing.

So if I take 6.440 - 3.31 = 3.13" , this would be my 'bellhousing flange to pressure plate fingers' measurement.

If I take that 3.13" and subtract my 3.25" compressed slave cylinder height from the previous thread, this means that I'd have -.120" of preload, which is almost twice as bad as what I have now (-.0625").

They think my slave cylinder is too long and want to know how many cars (specifically 2009s) are running stock slaves with RXT/RST clutches. I can't see how the slave cylinder is the problem (or how they got their measurements, since they seem so far off), so I need help getting the following info.

Could you please list the following information:

model year: 2009
engine block: LY6
crank: stock
bell housing: stock
torque tube: stock
clutch: RXT
flywheel: aluminum
slave cylinder: stock

carlrx7

What are the measurements supposed to be?

turbotuner20v

.125 - .220 of gap between bearing face and pp fingers

These are the only measurements they have:
Extension of crankshaft past engine block/bell housing flange - 0.330"
Flywheel thickness - 0.880"
Clutch assembly thickness - 2.100"
Bell housing flange to flange - 6.440"

but I doubt their accuracy

realcanuk

I have an A6 and am far from an expert on this topic but maybe something like this is needed?

http://forums.corvetteforum.com/c5-z...it-3-pack.html

turbotuner20v

A shim would just increase the preload. There are aftermarket slave cylinders available, but tons of people run this clutch with all stock parts with no issue. I don't want to spend the money on more parts since I think it's a problem on mcleods side.

realcanuk

That makes sense. I didn't think it out well. I have a few friends using this clutch. I had read your original thread and because I am nosey and like to learn as much as I can I asked my guy about this when I saw him yesterday. He has done a few of them on Z06's and C6's. He says he measures and hasn't had an issue, but he also mentioned, after a bad experience with the aluminum flywheel on a Camaro, he has only used steel ones on vettes. Maybe something with the flywheel thickness ?

nareg

I use the stock slave cylinder with the RXT and no issues.. How long have you had it? Have you always had a problem with it?

turbotuner20v

That could be... something in the stack up seems off.

It's frustrating that even using their on file measurements of stack height, it still seems like it would be preloaded...

turbotuner20v

I've had it ~2,000 miles. In those 2k miles, I've gone through 2 slave cylinders in ~1k miles each, so I believe it's always been an issue... I just took measurements this last time it was apart though.

Do you mind providing some of these details?

model year:
engine block:
crank:
bell housing:
torque tube:
clutch:
flywheel:
slave cylinder:

realcanuk

I can imagine it frustrating. Hopefully you will have thing figured out before, but in case not....
My guy is putting an RXT (steel flywheel) in my buddies Z06 but it wont be for another 10 days because he is out of town. When it is apart I can measure anything you need. I will check with you then if you still need the info.
I have another buddy who just did one this week, and he used the aluminum flywheel, but his is back together now so too late to measure.

turbotuner20v

That would be great, please keep me posted. I'd like to know the 'A' and 'B' measurements for sure, plus a few other misc.

I have everything back together and will be driving it till this latest slave cyilnder fails, so all of this is just to prepare for when I need to put in the final solution this winter.

realcanuk

Will do. I just phoned my friend who was currently doing it in case it was still apart. He is back together, says it feels great and chatters, just a tiny bit. I guess time will tell if all is perfect on that one.

turbotuner20v

The flywheel may be the key... perhaps a case of 'oops, put the wrong one in the box'?

560536 CHEVROLET 1997-2010 LS-X ; 0-Bal, Stl H/S, 168T R/G, .200" Thicker,Patt:5,13 $773.00

560535 CHEVROLET 1997-2010 LS-X ; 0-Bal, Stl H/S, 168T R/G, .400" Thicker, Patt: 5,13 $813.00

560530 CHEVROLET 1997-2010 LS-X ; 0-Bal, Stl H/S, 168T R/G. Patt: 5,13

I ordered 560530 (regular aluminum flywheel)

Perhaps I actually got 560536 (.200" thicker) or 560535 (.400" thicker)

camirocz

Just put my rxt clutch with aluminum flywheel and luke slave cylinder in today. Pedal feels really light.Used .05 synthetic fluid .I get a little rattling from the aluminum flywheel at idle,but that s normal.I just noticed that Jody told you i just completed the install today.

turbotuner20v

No other McLeod users?

BigV

I have McLeod RXT installed on my C6 Z06 with no issues.

realcanuk

Now that you show they sell thicker flywheels, it wouldn't surprise me if that is the issue. Camirocz told me that his RXT came directly from Mcleod, in the wrong box.

turbotuner20v

Stock slave cylinder?

Any of those extra details would be great

White_Lightning

RXT, Stock Slave, Dry sump LSX block. 5-6k miles on it.. seems to be doing fine so far..
I will be pulling it out in a month or 2 to drop in the Spec super twin. I will let you know the condition of the clutch when it comes out.

turbotuner20v

thanks


Any others?


It seems the preload has gotten worse over time... I am already having issues from putting it back together as-is. Slave seems to be chirping like it did before it failed last time, and also the clutch seems to be slipping.

Really hoping that McLeod will send me a new assembly to replace this one since something was off with it.