itsdaveonline

Hey got a 2006 CTS-V with 57k. It's had a clutch replaced once with a LS7 clutch. This was done only a few thousand miles ago, and it should have a brand new slave.

The clutch does not slip and it seems like it has plenty of grip.

But my issue is that the clutch feels a bit heavier than it should IMO... It also is a bit difficult to shift into gears. As if it's not fully disengaging or something. The shifter feels really stiff and feels like i have to really pull or push on it pretty good to get into gear. it doesn't glide into gear like it should. It get's better as the car is driven.

Based on this info, where should i start looking? The caddy has a remote bleeder, and we did some bleeding, but it didn't have any changes.

Any way to check if the master is bad? How much would a stealership charge for changing out a master?

ryridesmotox

Just get Philistine's master. I have an LS9 twin disc, katech flywheel, stock (replacement) slave. I'm not running any shims. I have a remote bleeder as well. In all honesty, if I did it again, I would bench bleed the slave out of the car to make sure and get ALL the air out. The design of the gm slaves allows for some air to be trapped in there... Which is no bueno since our clutch master's have more than enough problem as it is.

ls1247

iTrader: (2)

Thats it, throw parts at it.

Sounds like a slave shimming issue to me. Do a search for "slave shim" for more info.

ryridesmotox

Dude, I worry about your sanity. The clutch master issue in the V1 is pretty well documented. The LS7 doesn't require as much slave travel as an LS9. He has a brand new, or low mileage, slave with the recent clutch install. Unless the place that installed it, shimmed it we all know it will drag and block gears. Unless he is doing it himself, a shop will charge quite a bit of money to drop a trans and install the slave shim. Whereas he can do the master cylinder upgrade and do it himself for probably less. Its not a terribly hard install.

ls1247

iTrader: (2)

Its nice to know you care.

OP, do what you want but installing the PMC won't fix your problem in my opinion.

Good luck

Becker

iTrader: (4)

What is the shifter situation? I'm sure it is not the answer but its worth looking st it to ensure its not overly tightened at the pivot.

Does the clutch get better if you double pump it? Are you blocked out of any gears at times? Any noises while shifting?

These are some of the tell tales of master issues.

isis

iTrader: (1)

Shimming a dragging ls7 clutch that's already using the ls7 slave is a band-aid. The PMC is the actual solution.

itsdaveonline

Thanks for the comments guys.

I did talk with the previous owner not long ago (car is new to me). From what i remember him saying, is he did the clutch and he did use a shim / spacer, but took it out later for whatever reason. So i shouldn't have one in right now.

The transmission is always pretty quiet, and i don't believe it's a shifter issue. It doesn't totally block me out of gears, but it can be very difficult or excessively hard to get into 1st or R on cold starts. It's also worth noting the clutch feels a bit heavier than normal and it engages fairly low to the floor. But not right off the floor...

@ryridesmotox im on the same page here, yes a shim may be chaper and could do the trick. But i dont want to drop the trans. Id rather give the PMC a shot if you guys think my symptoms are that of a messed up master.

Fweasel

iTrader: (6)

I would start simple with fresh fluid, bleeding, and visual inspection of the visible hydraulic parts. Checking the shifter pivot for binding is also an easy checklist item as is assessing the condition of the shifter assembly and the collection of mashed potato bushings there in.

itsdaveonline

I've done a bleed with fresh fluid, and it didn't change anything. But i haven't checked the shifter in detail or looked at the bushings. Does the linkage or bushing normally go bad? Im less than 60k on the car.

My gut tells me the linkage and bushings are good. There is no slop in the shifter. It feels like somethings up with the hydraulics and the transmission is not allowing me to get into the gear. It doesn't feel like my shifter is binding up.

Any guides or advice on how to check the shifter anyhow?

ryridesmotox

What shifter do you have? It it stock, modified stock, or aftermarket. Your statement of zero slop, to me, means that there is something aftermarket in there. I have a Hurst shifter and polyurethane bushings. It takes a hammer to get into gears for 2 of the 3 people that have tried my car. I must be used to it... But to me its easy. I'd check the fluid, but assuming a proper install was done, it should have been bled at the very least, if not completely flushed. When I did my install I cleaned the whole system as best as I could. It was literally green with goo and nasty **** in there. When you bled it, was it clear?

itsdaveonline

From what i understand there is some sort of aftermarket shifter in there. Im not sure which one. It was like that when i bought the car a month ago from the previous owner - he told me about it but i forget the details.

I wouldn't be surprised if mine has polyurethane bushings too. It does require a bit more effort to shift into gears, but you can really feel the shifting pretty good, you know when it's in gear. Add the fact that im sure something is messed with the master and that's why im not liking the gearbox.

When we bled evreything the fluid was pretty dark, but i didn't notice any debree come out. I do have headers which aren't wrapped so i suppose the fluid could have boiled over a while back. But my new fluid and bleed didn't change anything. It was exactly the same.

ryridesmotox

Clutch fluid is just the same DOT3 **** that they put in the brakes. If its dark, its contaminated and needs a complete flush. Go to Napa and get a quart of dot4 or 5. Take the clutch master cylinder reservoir off and clean that out really good. Then bleed it til runs perfectly clear. If its coming out clear and no air at all, and you are still having problems, then look seriously at the master cylinder.

ls1247

iTrader: (2)

Wonder of the previous owner actually measured this or if he was just throwing shims at it to see how it worked? In other words, was he having the same problem you're having?

itsdaveonline

I'm not sure - he seemed fairly mechanically inclined. I mean he put in SS brake lines and they look fine. He also put in creative steel motor and tranny mounts + headers. Also got coilovers...Evreything seems to be holding up.

I'm sure he was having the same issues, but the master is the only thing that hasn't been touched yet. I'm guessing if it's flaking out, it will cause shifting issues with or without a shim.

The good thing is that the caddy is definetly still driveable, but i want to get this corrected because the gearbox feel SUCKS. The rest of the ride is awesome.

itsdaveonline

I've done this already, but with dot3. We bled it completely thru untill the fluid was perfectly clear.

Can we use dot 4 or 5 in the V? If so what's the advantage?

ls1247

iTrader: (2)

Even though he didn't really come right out and say it, Philistine pretty much told us in the other thread that the PMC won't compensate for a slave that isn't shimmed right. But the PO already tried shimming the slave and it didn't fix it so your next step it the PMC if the shifter checks out.

Even if it doesn't fix it, the PMC is a good investment.

Good Luck

ryridesmotox

The dot3 is fine. I wouldn't rebleed it just to put in dot4 or 5 in the hopes of it correcting the issue. Because it probably won't.

Advantage to a dot4, 5, or 6 is a higher boiling point. I used motul RBF600 in my clutch and brakes.

Disadvantage is you have to, or rather should, bleed yearly, and flush at least every other year. The accepted rule is, the higher the dot number, the more susceptible the brake fluid is to moisture. Therefore it requires more maintenance to keep in the operational range. As the fluid picks up moisture (water), the boiling point get lower and the fluid gets cloudy and nasty.

itsdaveonline

Good to know. I may put in dot 4 when i install the "pmc". Hopefully that fixes my issues. I just ordered it. I'll make sure to give it a real good bleed then.

Otherwise it looks like the transmission has to be dropped. And i don't want to do that anytime soon. The car sits way to low, id probably just let a mechanic do it. At least he'll have a lift

itsdaveonline

Oh also forgot to mention during bleeding the clutch pedal stays stuck to the floor and does not return after the bleeder valve was shut. I know the pedal is pretty stiff so i think the spring got flattened out or maybe was removed.

Also - I am familiar with bleeding and we would open the bleeder to push fluid out. Then close the valve and let my leg off the clutch. Only it wouldn't return. I'd have to pull it up. The pedal effort going down was normal / stiff too. Just no return...

Id assume that is a definite issue with the master?