Originally Posted by Zexell

I manage an O'Reillys and when I went to order a replacement it said "Not Authorized to by from vendor directly". That was 2 weeks ago.

Originally Posted by DarkCharisma

Side note, it appears the brass t-56 cup doesn't actually fit. I had to grind it down quite a bit to make it slide in.

Originally Posted by FuzzyLog1c

Common knowledge. If you look at any of the DIY threads, we've all had to do it.

Originally Posted by Fweasel

The isolator cup has nothing to do with the clutch install itself. It's an upgrade part that can be installed during a clutch install while the trans is out of the car. It helps eliminate slop in the shifter assembly. The outer flange of the cup needs to be ground down slightly to clear the shift selector assembly before dropping into place inside of the trans.

Originally Posted by FuzzyLog1c

Dead wrong.

Between the Cadillac CTS-V FAQ (a feature that most other usergroups would die for), the LS1Tech and Cadillac Forums are bristling with an embarrassing riches of guides covering almost all aspects of modifying this car. The best part is that most of the users who wrote these guides are still around--some of them may have moved on to a second generation CTS-V, but it's easy to find them and get help.



The only misleading information that you'll find is in the back-and-forth arguments about whether the clutch needs a shim or not. There is no debate about anything else.



That's not the cheapest solution. You still have to buy a 26-spline tool, pilot bearing, and slave cylinder, and after that you're stuck with a heavier flywheel and you're playing Russian Roulette with the variable build quality on the GM pressure plate (sometimes the springs arrive broken, or the automatic adjustment mechanism is jammed). The Stage 1 F1 kit is the cheapest option, although you should really pony up another $100 and get the F1 Racing MF kit with the powdercoated pressure plate. That's the best value you'll find on a LS7 clutch kit. As a bonus, it's good for another 100 ft-lbs of torque (578 ft-lbs, as opposed to 475 ft-lbs), and F1 sells replacement MF discs for about $100.



As previously stated (and this part nobody can blame you on), the only misleading information is in the back-and-forth debates that raged about whether the LS7 clutch needed a shim to work with the CTS-V or not. If you followed the trail of discussion to the bitter end (a feat in and of itself), you would've gotten the right answer: replace your LS2 slave with a PowerTorque CS2529 slave for your LS7 clutch and torque the pressure plates to 48 (my recommendation) or 52 (manual's recommendation) ft-lbs. No shim required.

You would have also been directed to the resource that would have gotten you at least 3/4 of the way to the correct solution, by teaching you how to do the clutch measurements yourself.

The missing piece of information that settled the shim debate was what I contributed back in early 2011 (after installing and reinstalling my LS7 clutch 6-7 times): the discovery that the pressure plate torque specs were vehicle specific, not clutch specific. This is something that most LSx specific shops and tuners were unaware of at the time.

If you followed the CTS-V FAQ, you were told that the stock LS2 pressure plate torque spec was 52 ft-lbs. If you read the LS7-powered Z06 Corvette guides, you torqued the pressure plate to 74 ft-lbs. GTO guides were all over the place, since they borrowed parts from everywhere. As a result, CTS-V owners that torqued their pressure plates to 52 ft-lbs couldn't understand why CTS-V owners who torqued their pressure plates to something else (e.g. 74 ft-lbs) were complaining about partial disengagement of their clutches and talking about shimming their slaves.

Nobody realized that the actual problem was torque--it would take someone with a tendency to massively over-torque everything (I had broken over 15 piece of 3/8" drive and 3 pieces of 1/2" drive, not including two socket wrenches, overtorquing bolts before having this epiphany and learning the value of the torque wrench) to discover the answer.

Since torquing pressure plate bolts beyond 45 ft-lbs causes the fingers on the pressure plate to gradually retract, additional torque can be specified to increase the spacing between the fingers of an installed pressure plate and front face of the slave's throw-out bearing. Slight differences between the spacing in various cars resulted in various torque specifications, and in the case of the CTS-V, spawned a debate that lasted for years.



You're right. That's interesting--it wasn't like this in years prior. I did a quick check: LS3 and LSA slaves are easy to find, but they're not the same size as the LS7 slave, so future LS7 installations may require what the experts do by default: measure and adjust to compensate--either via additional torque (if spacing is lacking) or by shimming (if spacing is too great).



Be very careful with that statement. There are several LS7 slaves that have different throw out bearing lengths and diameters. Unless you confirmed that the GM part number for both vehicles is the same, I wouldn't have said that.



That was a big mistake, for which you'll be kicking yourself later. If you actually drive the car, you need to be bleeding your clutch fluid at least once or twice per year (more often if you're aggressive, or participate in track events).



There was "something out there" that could have guided you a lot, if you did your research. Don't blame the community--blame yourself.

Originally Posted by FuzzyLog1c

Short version:

• Use a torque wrench on all the clutch and flywheel bolts, otherwise you'll have vibrations and disengagement problems. I'm deadly serious about this--no torque wrench, don't attempt this job.
• I don't have the precise A-to-B distance on the LS7 clutch in the CTS-V T-56 to give you. I have numbers that I used to believe in, but my tools sucked back then. Sorry.
• Having used a number of different slave brands, I highly recommend Tilton adjustable slave cylinders over McLeod and OEM-type bearings. The LS7 slave was intended for the Corvette bellhousing and isn't perfect for the V1. Most people choke on the cost of a Tilton slave, but what you'll really choke on is the time and money that having a poorly adjusted slave will cost you.
• One factor I failed to account for in my earlier A-B calculations was the "squish" (compression) of the stackup of components that comprise a hydraulic slave when it's supplying hundreds of pounds of force. The throwout bearing on the slave in particular compresses a lot under load--try throwing your unit under the meager force of a bench vise and you'll see. Ultimately, you should adjust your slave to be a little closer to the clutch than the unloaded A-to-B measurements make it seem to be.
• People worry about pilot bearings way too much. They rarely fail. Any OEM one will work--check it out on RockAuto. Replacing the pilot bearing under the car is almost impossible to do "the right way" with a slide hammer. There isn't enough room to develop the force, and you'll kill your ears. People warn about grease packing, but it's the only method I've found that works. Maybe, if you have the engine out of the car, a slide hammer will extract the bearing, but if I couldn't do it under the car at a mere 10-15k miles (before serious corrosion could set in), I doubt you'll have success either.
• If you're doing this under the car, it's a party trying to get the transmission back in. Before trying, spray dry graphite lube on the T-56 input shaft splines--night and day difference on the friction. Also don't forget to have the transmission in gear, which enables you to spin the propeller shaft with your back hand to align the splines as you try to slam the transmission into place. Once the splines are in place, you shouldn't need tools to push it in, but it doesn't hurt to have a dead blow mallet on hand.
• If you use the threads on the bellhousing to pull the transmission in, eventually you will fatigue the threads and the bellhousing will need to be replaced. Getting an SFI-rated steel bellhousing (e.g. Quicktime) before that happens is a good idea if you have unlimited budget. If you've never done this before, but it sounds interesting, get yourself a set of longer bolts to reach further--it'll help.
• Whatever you do, make sure you get a (1) remote bleeder line, (2) speed bleeder or equivalent check valve for the remote line, (3) new shifter bushings if you've never replaced them, (4) a short shifter, and (5) new transmission oil if you've never replaced it.
• This is only a tip for those without a lift: get this motorcycle jack to raise and lower the transmission. Take the top pieces off so you're left with a slippery platform (which enables you to take the weight off the end while you're working on getting the splines engaged), and remove the handle extension so it's as short as possible.
• When you're retightening the bolts on the transmission, a little pro tip is to use a hydraulic jack and a flat piece of wood to gently (GENTLY) tilt the engine so that the transmission tilts a little further down. This really makes a difference when you're trying to get at those top bolts with 4' of socket extension hanging off your torque wrench. Oh, and get a Zebralight or equivalent high quality headlamp.
• The only thing I don't really have a tip for is getting the transmission and the engine separated. Despite worries about overtravel on the slave, I always found it necessary to hit the clutch pedal a few times (really hard) to get initial separation, and then stick a huge flat blade screwdriver (or a short flat prybar) into the gap to help separate the transmission from the bellhousing. Maybe there's a wider flat prybar that'll fit in there.
• Budget 3-5 days for your first attempt. Theoretically you can do the job with one person in one day, but your first time with the transmission is going to be a massive learning experience not unlike your first attempt at removing subframe bushings. Go in assuming it'll take your car out of commission for 5x as long as you think it should and you'll spend 3x as much money on stuff including tools as you think you will.

Originally Posted by FuzzyLog1c

Short version:

• Use a torque wrench on all the clutch and flywheel bolts, otherwise you'll have vibrations and disengagement problems. I'm deadly serious about this--no torque wrench, don't attempt this job.
• I don't have the precise A-to-B distance on the LS7 clutch in the CTS-V T-56 to give you. I have numbers that I used to believe in, but my tools sucked back then. Sorry.
• Having used a number of different slave brands, I highly recommend Tilton adjustable slave cylinders over McLeod and OEM-type bearings. The LS7 slave was intended for the Corvette bellhousing and isn't perfect for the V1. Most people choke on the cost of a Tilton slave, but what you'll really choke on is the time and money that having a poorly adjusted slave will cost you.
• One factor I failed to account for in my earlier A-B calculations was the "squish" (compression) of the stackup of components that comprise a hydraulic slave when it's supplying hundreds of pounds of force. The throwout bearing on the slave in particular compresses a lot under load--try throwing your unit under the meager force of a bench vise and you'll see. Ultimately, you should adjust your slave to be a little closer to the clutch than the unloaded A-to-B measurements make it seem to be.
• People worry about pilot bearings way too much. They rarely fail. Any OEM one will work--check it out on RockAuto. Replacing the pilot bearing under the car is almost impossible to do "the right way" with a slide hammer. There isn't enough room to develop the force, and you'll kill your ears. People warn about grease packing, but it's the only method I've found that works. Maybe, if you have the engine out of the car, a slide hammer will extract the bearing, but if I couldn't do it under the car at a mere 10-15k miles (before serious corrosion could set in), I doubt you'll have success either.
• If you're doing this under the car, it's a party trying to get the transmission back in. Before trying, spray dry graphite lube on the T-56 input shaft splines--night and day difference on the friction. Also don't forget to have the transmission in gear, which enables you to spin the propeller shaft with your back hand to align the splines as you try to slam the transmission into place. Once the splines are in place, you shouldn't need tools to push it in, but it doesn't hurt to have a dead blow mallet on hand.
• If you use the threads on the bellhousing to pull the transmission in, eventually you will fatigue the threads and the bellhousing will need to be replaced. Getting an SFI-rated steel bellhousing (e.g. Quicktime) before that happens is a good idea if you have unlimited budget. If you've never done this before, but it sounds interesting, get yourself a set of longer bolts to reach further--it'll help.
• Whatever you do, make sure you get a (1) remote bleeder line, (2) speed bleeder or equivalent check valve for the remote line, (3) new shifter bushings if you've never replaced them, (4) a short shifter, and (5) new transmission oil if you've never replaced it.
• This is only a tip for those without a lift: get this motorcycle jack to raise and lower the transmission. Take the top pieces off so you're left with a slippery platform (which enables you to take the weight off the end while you're working on getting the splines engaged), and remove the handle extension so it's as short as possible.
• When you're retightening the bolts on the transmission, a little pro tip is to use a hydraulic jack and a flat piece of wood to gently (GENTLY) tilt the engine so that the transmission tilts a little further down. This really makes a difference when you're trying to get at those top bolts with 4' of socket extension hanging off your torque wrench. Oh, and get a Zebralight or equivalent high quality headlamp.
• The only thing I don't really have a tip for is getting the transmission and the engine separated. Despite worries about overtravel on the slave, I always found it necessary to hit the clutch pedal a few times (really hard) to get initial separation, and then stick a huge flat blade screwdriver (or a short flat prybar) into the gap to help separate the transmission from the bellhousing. Maybe there's a wider flat prybar that'll fit in there.
• Budget 3-5 days for your first attempt. Theoretically you can do the job with one person in one day, but your first time with the transmission is going to be a massive learning experience not unlike your first attempt at removing subframe bushings. Go in assuming it'll take your car out of commission for 5x as long as you think it should and you'll spend 3x as much money on stuff including tools as you think you will.