FuzzyLog1c

iTrader: (4)

Incorrect. However, after looking at Corvette bellhousing lengths further, it looks like the C6 (05-09) bellhousing is actually 6.440", which is significantly longer than the 5.786" C5 (97-04) bellhousing. Obviously, both of those are longer than the front-engine GM LS engine to T-56 bellhousing, which measures 5.500".

ls1247

iTrader: (2)

You keep hinting that there should be a difference between the clutch assembly we need and the LS7 clutch assembly many of us have been using due to different bell housing depths.

In your mind, is this true or false?

InfrareV

The CTS-V bellhousing is longer than the F-Body hellhousing, I believe this is to allow for the factory dual mass flywheel. I believe it's the same 5.786" you've quoted as a C5 bellhousing.

I was unaware the C6 bellhousing was even longer yet, perhaps the C6 torque tube protrudes into the bellhousing? Otherwise we would all have a 3/4" gap between the LS7 clutch and the LS7 slave?

ls1247

iTrader: (2)

I guess Fuzzylogic won't continue this conversation because I'm 3rd gen V1 owner trash so I talked with Lee at McLeod about this and he suggest running the 6405507 with a factory ls7 slave as a twin disc replacement for V1. He further stated that there would be no need to concern ourselves with measuring or shimming the slave as they've done their homework and their clutches work as they should right out of the box.

This is the same clutch configuration they offer for all other rear wheel drive LS engine applications including the Z06. It isn't hard to verify if you check the application chart here...

https://www.mcleodracing.com/index.p...h_visibility=1

or by checking out any other 6 bolt LS application you can think of which all would use the 6405507 or the 6405507HD heavy duty version of it if you need a clutch that can withstand a 1000hp.

Throughout the search of their website, you will find no reference to slave cylinder differences either so no matter what kind of rear drive LS vehicle you have, you can buy a clutch off their website and they show no concern with what type of slave you're running.

Do I know much about clutches? No, I valued Lee's time enough not to tie him up for an hour asking him a bunch of questions about his trade like I'll assume others in the thread have done. But I do know how, in all my 3rd gen V1 owner trashiness, to read an application chart and look for notations that would affect my ability to use their products...

With out the benefit of more clarity, this seems to be the conclusion....

raven154

iTrader: (14)

The C6 and the V share the same bell housing depth. I thought this was settled a long time ago when Katech challenged me on the same subject and come to find out I was right. Imagine that.

ls1247

iTrader: (2)

Are these numbers published anywhere or did you measure the 2 transmissions yourself? If they're published, I couldn't find them.

FuzzyLog1c

iTrader: (4)

I'd be very surprised if Lee said that. That said, I've never seen as much confusion as there is regarding LS7 slave length--to this day, I'm still not 100% certain why some 3rd-party suppliers advertise their slaves as LS7 compatible when their length is not correct and not the same as OEM.

If you're still unclear on bellhousing length, go compare the length of SFI-approved steel bellhousings for front-engined Gen III/Gen IV cars, C5 Corvettes, and C6 Corvettes. You'll find they're the lengths I identified earlier.

ls1247

iTrader: (2)

That's what the man said and he didn't seem confused about it all as I confirmed it twice.

So either Lee's wrong, Raven154 is wrong, I'm wrong or your wrong. I'm not seeing any direct evidence from anyone and I've been looking...I wouldn't trust aftermarket SFI bellhousing numbers as GM gospel although they do support what you say.

raven154

iTrader: (14)

I measured mine back when I did the LS7 Exedy twin disk install but I don't recall the numbers. Based on the fact that my car has an entire clutch system out of a C6 currently installed with no issues whatsoever (Exedy twin WITHOUT an adjustable cover and a C6 slave) I came to the assumption that the V bell housing and the C6 bell housing was the of the same dimension. KATECH TOLD ME IT WASN'T! I kept telling them they where wrong and they insisted I was wrong. Finally somebody took them a first gen V and now they are selling first gen V LS9 twin disk clutch kits.

They came back and said that the engineering data they had was wrong and that the bell housings where in fact of the same dimensions. So all this bullshit about the LS7 only working because it has an adjustable cover is just that, bullshit. Myself as well as a few others have installed the GT04SD Exedy with the C6 slave with absolutely no issues and Katech sells the LS9 twin that bolts in a First gen V with stock or LS9 slave.

All of this would absolutely only be possible if they bell housings where in fact the same dimensions.

Guess my Cadillac forums thread got deleted or something. Nothing comes anymore when you click the link but here is the thread advertising the NEW release of the Katech LS9 twin for the V lol

https://ls1tech.com/forums/cadillac-...kit-cts-v.html

wes8398

iTrader: (2)

It's amazing that this whole debate is still going on. There must be hundreds of LS7 clutch kits in V1's by now. Don't you think that over that period of time, there'd be numerous complaints of failures by now if what FuzzyLog!c has to say about shimming/gap was accurate?

I can say this... I've DD'd my V for 2 years and somewhere around 20,000 kilometers with my setup (see post 88) which includes approximately 0.089" of (accidental: see post 99) "preload" without any catastrophic issue. This includes a couple auto-x's here and there through the summer, some severe winter driving, and a lot of basic grocery-getting, city driving. No spun pilot bearing, no "blown out" slave, no blocked gears, etc.

The only complaint I have is that it doesn't shift any better than it did with the OEM dual mass clutch. A lot of the vibrations are gone (which was probably the main reason I wanted to dump the dual mass), but it's still a very notchy, clunky shifting car. Which is why I bought Philistine's MC over a year ago. With all this controversy being in its infancy at the time, I decided to leave it on my workbench until things all got sorted out. There it sits... still...

ls1247

iTrader: (2)

This is why I'll continue to push the conversation forward. My V1 is a huge leap forward to the cars I grew up with except in this regard. Super t-10s and M-22s shifted better than my t-56 and it doesn't inspire much confidence when it comes to banging gears.

While I was hoping someone would come up with published GM bellhousing depth numbers, this works for me. Thanks for posting this!

This is fuzzy logic.

raven154

iTrader: (14)

I'm fairly certain Katech should be able to provide those numbers.

isis

iTrader: (1)

I like this thread. Thanks for pushing it forward. So much noise on the subject anymore.

2007V

iTrader: (2)

I'm installing a trans right now and going through this stuff, transzilla and rst clutch. The whole setup is changed so I have some measurements. The transzilla has a different front plate which moves the slave forward from OEM.

Not sure if this was posted earlier as I just skimmed the thread.

OEM bellhousing is 5.85" deep
OEM slave is 3.2" mounting face to bearing face extended
LS7 slave is 4.1" mounting face to bearing face extended
Both slaves compress 0.80"

A LS7 slave will not work with a transzilla (TR6060) from RSG for future reference.

ls1247

iTrader: (2)

Let's us know what you're using and how the new transmission shifts please. I've looked at this as an option so this would be good information.

Thanks!

2007V

iTrader: (2)

Mine should be going tonight and I'll let you know. I'm changing the master cylinder as well.

RJ has the same setup and he can shift fast as hell so I have high hopes!

vroom_vroom

iTrader: (5)

so is it just me or is this the most sound of the clutch swaps?

ls1247

iTrader: (2)

My ls7 still works and as much as I drive on the highway, I don't see me replacing it anytime soon.

We hear a lot of "this will be awesome" around here so it's hard to say about the McLeod package.

It's rated for 800hp so if you need a stout clutch package, it might be the way to go. It sounds good and the guys have a good reputation but the McLeod setup, by the time you buy the slave seperately, will cost twice what an LS7 setup does. Not many of us need that.

Anybody tried the McLeod clutch referenced above??

vroom_vroom

iTrader: (5)

true, you will pay. what ended up being the "final" word on the ls7 setup. some shim some dont? or bad flywheels? have re read this thread and seem to be just as confused.

ls1247

iTrader: (2)

I get the feeling the ls7 clutch is about as good as it gets for the money as a stock replacement clutch for the V1.

But I can't tell you it's perfect because of other issues in the car that could be identified with having the "not so perfect" clutch. My V1 could shift better as compared to other cars I've owned but there are a host of other factors, besides the clutch, that I know are affecting it. Others will say it shifts great and if I'd never owned better, I'd probably say the same thing.

First, is my laziness to keep fooling with the PMC. I don't beat on the car much, I drive it fast but I'm not clutch dumping and gear banging in it. My work is either feast or famine and right now its feast so I'm not spending what little time I have off underneath the dash trying to get that last 5% out of the clutch setup. It'll get me to work, no problem for now...but the rest is all on me and not a reflection on the PMC.

https://ls1tech.com/forums/cadillac-...-cylinder.html

Next we have the remote shifter. I've had several different shifters in the car and they all yield pretty much the same result...decent shift quality at best. Yes, I've done the bushings and even welded tabs to the shifter base and bolted it solidly to the transmission so it couldn't move at all but it didn't really help. The linkage has too many moving parts in my opinion and I think Cadillac thought the same thing if you look at the V2 tr-6060.

The next part of the equation is the transmission. Is the t56 the best shifting alternative out there? Probably not...Cadillac made a host of improvements when they upgraded the V2 to a tr6060 and I tried to outline them in the post below...

https://ls1tech.com/forums/cadillac-...0-into-v1.html

My ls7 clutch gets me around fine but none of it's great in my opinion.

Edit...I didn't have to shim mine and it seems nobody else needed them either even thought they tried them.