Onefast V

iTrader: (3)

So I had the ls9 clutch installed a while ago and had some engagement issues where it was very difficult to get into gear when running. Reverse was by far the worst . J have put almost 1200 miles on the new setup. I have put in a new slave, master, tranny mount, new atf fluid (syncromesh), bled many times with a power bleeder. So I came to the conclusion it must need to be shimmed. Well I pulled out the tranny.measured the distance from the transmission surface to the top of the fully compressed slave with the throwout bearing. The measurement was. 1.58in. I then measured from the bellhousing surface to the pressure plate fingers. The measurement was. 1.68 in. So normally they recommend .175-.225 of spacing. So I'm at a loss for the issue as it obviously doesn't need the slave to be shimmed. Help please!

heavymetals

iTrader: (3)

I am just getting ready to install mine.

Hope I don't have this problem.

Dmax/04V

You guys doing this with the katech clutch/flywheel kit? I'm running the katech ls9x kit and no spacers where needed, but it took a little while to break in.

wcryan

iTrader: (2)

^ how long is a while?

took about 4-500 for the LS7

Dmax/04V

To be honest I don't remember exactly, I drove from AZ to FL the day after I did it. I just remember it being smoother after a while.....then my slave cracked a week later. New slave and smooth as butter.

cam3439

If I remember correctly, N/A was 2-300 miles and boosted was 500 miles for break-in.

FuzzyLog1c

iTrader: (4)

Tick says the gap should be between 1/16" and 1/8". It sounds like you're fine in terms of separation, as you said.

I'm beginning to wonder if this is a symptom of the CS transmission mount you added. Before the install, your OEM motor and transmission mounts were sagging by roughly the same amount. By refreshing the tranny mount and leaving the motor mounts the same, you probably threw everything out of alignment.

Try parking the car on a steep incline and decline and trying to shift into reverse. Good mounts should support the engine under these conditions. Bad mounts should allow the weight of the motor to shift slightly, either exacerbating or improving the situation. Just a theory right now.

Onefast V

iTrader: (3)

I have brand new UMI motors mounts that went in before the clutch. The transmission mount did not get installed until several hundred miles after the clutch as well as i thought it might help the problem. When I pulled out the OEM transmission mount it looked brand new and in great condition. I'm really at a loss unless it is something mechanical in the clutch mechanism that perhaps has too much slop.. BTW I confirmed the tick performance shims do in fact fit fine on our cars.

This is the LS9X kit from Katech

Dmax/04V

One Fast V how are your shifter bushings? I had reverse and 1st gear issues until I swapped those out even after a new clutch, shifter, and trans/motor mounts.

Onefast V

iTrader: (3)

I have a UUC shifter with the UUC bushings. For the most part all of the bushing looked to be in good condition. I am also in the process (as part of this tear down) of adding the PVC bushings and brass cup isolator bushing from Cadzillas thread.

Dmax/04V

How many miles on the trans? Hopefully the problem is in the linkage, not internal to the trans.

FuzzyLog1c

iTrader: (4)

When the transmission doesn't want to shift, does pumping the pedal multiple times help?

Onefast V

iTrader: (3)

110K on the transmission, which shifted great before the LS9 clutch was installed.

It does not make any difference. The transmission will shift into gear, it just requires significantly more force. When the car is in gear with the clutch pedal fully depressed and on a very level surface, the car will slowly roll forward.

heavymetals

iTrader: (3)

That ain't right.

Maybe the clutch disc got bent on the install?

Dmax/04V

Did You preheat the flywheel before mounting it? Aluminum flywheel has to be heated.

garrettg

iTrader: (1)

Are you using the original/new cts-v slave or a new ls9 slave? 110k on the stock slave might be time for replacement if its not extending far enough to separate both discs from the flywheel.

FuzzyLog1c

iTrader: (4)

It sounds like you have exactly the same problem that I have (clutch not fully disengaging). I have the Tick shim kit and hope to install it this weekend, weather permitting. I'll try to remember to let you know what happens with it. I plan on getting as close to 1/8" spacing as possible.

Onefast V

iTrader: (3)

I thought i had the exact same problem until i measured that distance and was at .10 inches. So i think they are different root causes with similar symptoms.

replaced with a brand new slave at the time of the clutch install so about 1k mikes on it. no fluid or wet spots indicating its leaking.

I didn't originally install it, I had a mechanic install it who done good work for me before so I'm trying to troubleshoot his install. I've never heard of anyone preheated their flywheel before installation.

Another possibility. I believe the disc directly behind the pressure plate is fixed in position, perhaps the one behind it is bent? Are we talking a very obvious bend? something i can visually see?

Onefast V

iTrader: (3)

I plan on measuring the total throw of the slave cylinder. And I believe on the bell housing side i would measure the pressure plate fingers into the the clutch disc to make sure there is sufficient throw in the slave itself

heavymetals

iTrader: (3)

I think you have to measure the total throw with it loaded.

As for a bent disc, from what I read, it can happen and it doesn't take much for a cockeyed spline to do it.

Forcing the mating being the biggest cause.

You may double check the flywheel thickness.