Well I installed a ls7 clutch, ram aluminum flwheel, arp pressure plate and flywheel bolts, and ls7 slave a few months back. Break-in went smooth, except I could not go into reverse with the car running. It would lock me out of gear above 4500 rpms(no grind, just wouldn't slide into gear), and failed rev test.

I pulled the trans to measure and ended up with measurement A- 2 7/16 or 2.4375 and measurement B- 2 5/16 or 2.3125. I installed a (.113) shim from Tick, now everything is perfect. Shifting into reverse is as smooth as any other gear, and can shift at 6500. Maybe it was the aluminum flywheel that made me have to shim but I recommend checking measurements anyway since it only takes a few seconds. Hope no one else has this problem.

 

The reason you couldn't go into reverse was clutch drag as you have discovered. Good thing you found it or the clutch/pressure plate would likely die a quick death.

 

It must be because of the ram flywheel? I never had any issues with my LS7 flywheel.

 

Seems interesting, I have an ls7 with ram flywheel and it is very smooth

 

So it sounds like I should order a shim kit just in case? I dont want to measure then the car be down while I wait for shipping. I am torn between the RAM ls7 vs stock, I daily drive mine but would love to feel 19lb instead of 28lb (i think thats correct).

Any other inputs? sorry to thread jack.-kinda

 

Also can you clarify the clutch draggin statement? I am thinking that the slave does not have enough throw to compress the fingers during these said "mis shifts" and that adding a shim would move the slave surface towards the fingers to in turn compress the fingers more.

Are you saying the clutch is dragging only when he shifts or all the time?

 

It's odd that the bottom end of the clearance, 0.125", would drag. So your clearance is now 0.012? I don't doubt it fixed it but your initial calculation was already at the low end of what Tick recommends. Or did I calculate it incorrectly?

 

I actually helped do the original install on this clutch. We didn't measure just because this is a pretty common mod and not too many people seem to have an issue running the LS7 stuff.

The clutch was dragging all the time. You could push the clutch and rev it and the car would creep forward and you could smell the clutch. Also, the car wouldn't go into reverse with the motor running unless the car was already rolling a little. And trust me, this thing is bled. We bled and bled and bled trying to get this thing to work and it just never would stop dragging. After the shim, the car is doing great.

The shims come in a package of three with varrying sizes. I would pick one up and then send it back if you end up not needing it.

 

You have your math right Brian. Not sure what up with this particular clutch but it just didn't want to work at .125".

 

Great to know. Thx. Raven how is the characteristics of the clutch as far as drive ability. ? I am still torn between the two

 

It drives like stock minus all the weight lol revs rise and fall faster. Car just feels lighter under acceleration because of less rotating mass. Other than that, I would say its not much different.

 

All factors being: ram flywheel not within standard spec... Slave not within standard spec...air in the lines...master cylinder not moving enough volume... A bundle of wires jammed in the bell housing mating seam on each side...haha. Not likely.

 

Yeah I knew I was within spec of Tick but I knew I was obviously having a problem. The slave was brand new from a local stealership because Oreilly's had stopped selling their replacement(which is now stocked again for future reference). Also, figured it couldn't be the master because the car was fine before the swap.

 

Brian pointed me over to this thread because I just had an LS7 clutch and slave installed last week and I'm experiencing issues with getting into reverse and other shifts being difficult at times too. Was hoping/thinking it was just a matter of breaking it in (I'm less only about 60 miles into it), bleeding it a million times (I've put 2+ quarts through it via 6 or 7 separate bleeds thus far), and just getting used to a new feel..... buuuuut, apparently that may not be the case. Mine's not dragging so bad that the car will creep forward with the pedal depressed in forward gears, but now that I think of it I do think it was doing that the other day when I was backing it into a parking spot.

The "kit" that I got was http://www.ebay.com/itm/FX-STAGE-1-CLUTCH-KIT-SLAVE-FLYWHEEL-CORVETTE-C6-6-0L-LS2-6-2L-LS3-Z06-7-0L-LS7-/400687835050?pt=Motors_Car_Truck_Parts_Accessories&vxp=mtr&hash=item5d4adb27aa#ht_3461wt_1153 which is basically a painted LUK pressure plate and OEM-like clutch disk and lightweight chromoly flywheel.

After over a year of researching and reading EVERY thread I could on this mod, I thought I had it all figured out enough to be a smooth install with little-to-no issues afterward. I'm very frustrated to find out that the "final word" on the battle of having to shim the slave or not is not what I had thought after all the research and consultations with other members. The determining factor for needing to shim or not was supposed to be whether you over-torqued the pressure plate bolts or not. Now while I didn't turn the bolts myself, my mechanic was absolutely sure to torque the PP bolts to 48 ft lb...the setting that was supposed to have been tried and true NOT to cause issues like I'm having.

Looks like lucky me is going to have to bring it back into the shop and have them basically re-do the better part of the install... Ugh. I'm just praying that this issue hasn't done any damage to the clutch disk in terms of glazing it or otherwise foiling my break-in efforts.

 

I thought I remember a big thread about ARP pressure plate bolts being a tad to long so even when torqued, they were bottoming out in the holes and not actually holding the pressure plate down correctly. ??

 

You remember correctly (although they apparently work fine with the Scoggin Dickey and other kits)... but I didn't use ARP bolts. I just had the shop reuse the OEM bolts, and if they needed to replace any of them I made sure they didn't try to use ARP's.

 

Sorry to hear about your luck Wes. I used the kit from sdparts with the pressure plate torqued to 48 ft. lbs.

I felt the same way after bleeding about as much as you have, and even swapped in another brand new pressure plate and disk with the same result.

All I can recommend is check measurements since you don't have an oem flywheel.

 

I thought OEM bolts were torque to yield/ one time use? Or am I thinking of the "loctite" they have on them from factory?

Regardless, I've always replaced them when changing a clutch out.

 

That would be news to me. I'm pretty confident my mechanic would have recognized TTY bolts and had them replaced before reinstalling too...

Thanks. So you didn't use the Katech spacer from Tick, right? That thing is huge compared to the shims they sell (that say they aren't for use on ctsv)...

 

The Katech spacer is for a single mass LS6 clutch with the stock slave. The shims they sells are the correct ones and I don't know why they would say its not for the V. These cars share the same transmission and slave style so the shims will work. If you call and talk to Tick, they will tell you they have shimmed several LS7 clutched V's.