Clutch Drag
05-01-2014, 03:42 PM
#1
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Clutch Drag My clutch has been dragging for the past few months, and I've been babying it as much as possible. Pressing it all the way down doesn't fully disengage.
Pressing it all the way down and throwing it into first from a dead stop, the car surges forward a bit. Reving to 6k, and the car moves forward, while holding the clutch down.
This issue has existed for a while, but has become more prevalent and causing misshifts now. I'm going with a different clutch\flywheel combo, and I'm trying to see what I should go with.
I'd like to hear opinions on clutch setup, prices, and any ways you guys have figured out to deal with clutch drag in general. I was thinking LS7 setup, but I'm hearing this exists with the LS7 as well, so if I can SOLVE without replacing... that helps.
[edit]
Replaced with full SPEC clutch setup, as well as Wilwood master cylinder. Solved issue
Pressing it all the way down and throwing it into first from a dead stop, the car surges forward a bit. Reving to 6k, and the car moves forward, while holding the clutch down.
This issue has existed for a while, but has become more prevalent and causing misshifts now. I'm going with a different clutch\flywheel combo, and I'm trying to see what I should go with.
I'd like to hear opinions on clutch setup, prices, and any ways you guys have figured out to deal with clutch drag in general. I was thinking LS7 setup, but I'm hearing this exists with the LS7 as well, so if I can SOLVE without replacing... that helps.
[edit]
Replaced with full SPEC clutch setup, as well as Wilwood master cylinder. Solved issue
Last edited by odthetruth; 09-10-2015 at 03:57 PM.
05-01-2014, 04:21 PM
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Assuming you bled the crap out of it and know for sure there are no air pockets in the hydraulics...
Personally I went with the Monster setup a couple years ago and haven't had any drag issues whatsoever. However, I would say to avoid going with the stage 3 or any puck style clutch if you DD the car. Way too much chatter and abruptness for my liking. I think it contributed to me breaking more rear end components but that's part driver mod.
The LS7 setup seemed like a sweet deal. I didn't know people were having issues with it.
Personally I went with the Monster setup a couple years ago and haven't had any drag issues whatsoever. However, I would say to avoid going with the stage 3 or any puck style clutch if you DD the car. Way too much chatter and abruptness for my liking. I think it contributed to me breaking more rear end components but that's part driver mod.
The LS7 setup seemed like a sweet deal. I didn't know people were having issues with it.
05-01-2014, 05:38 PM
#5
There is a bit of controversy surrounding this topic but as of today, I haven't heard of anyone having problems with genuine OEM GM factory LS7 clutch kits and thats about all we do know. If anyone has had shimming or dragging issues with a complete OEM setup, please let us know. Thanks
05-01-2014, 05:46 PM
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It's been said multiple times no matter what your installing you should take the time and take measurements to verify if a shim is needed.
Master Cylinder could be potential if it's a stock clutch. Sounds odd it's on the stock clutch and you have dragging whrn nobody else does.
Master Cylinder could be potential if it's a stock clutch. Sounds odd it's on the stock clutch and you have dragging whrn nobody else does.
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05-02-2014, 12:18 PM
#9
OP - What's your plan here; to upgrade or to repair? If you go the route of upgrading to an LS7 setup, you'll LOVE the new feel of the car. The car feels SO much lighter with an LS7 installed. I went with the eBay vendor Gripforce and got the whole package, OEM LUK pressure plate and disk with "F1 Racing" (been rebranded as "FX racing" now) ~20 Lb flywheel and the car felt like a whole new beast with that installed. I had some pretty significant vibrations and some rattling from my bell housing before this, and that's all completely gone now. The car goes through the revs smooth as butter now.
Something to note though - Read this thread (well, skip the last few pages) regarding the install of any LS7 clutch/slave setup. There are also tonnes of other threads with a lot of useful info regarding tips, tricks, and suggestions for the install. Pressure plate bolt torquing (to 48 ft lb) is VERY important to the success of the install as well. Lots of guys learned this the hard way.
Yup. The LS7 slave may also need a shim installed with it. Or you can use an ls2/ls6 slave with a Katech spacer, but those slaves are a lot more money to buy and the swap is done using LS7 slaves much more often (so you'll get more support around these places if you have issues).
If/when you get serious about this mod, just search "LS7 clutch" in the cts-v section of this forum, or Google search "CTSV LS7 clutch" and you'll get LOTS of info about the intricacies of the job. There are even a couple threads that do a good job of summarizing all the tips and tricks you'll want to be aware of.
Something to note though - Read this thread (well, skip the last few pages) regarding the install of any LS7 clutch/slave setup. There are also tonnes of other threads with a lot of useful info regarding tips, tricks, and suggestions for the install. Pressure plate bolt torquing (to 48 ft lb) is VERY important to the success of the install as well. Lots of guys learned this the hard way.
Yup. The LS7 slave may also need a shim installed with it. Or you can use an ls2/ls6 slave with a Katech spacer, but those slaves are a lot more money to buy and the swap is done using LS7 slaves much more often (so you'll get more support around these places if you have issues).
If/when you get serious about this mod, just search "LS7 clutch" in the cts-v section of this forum, or Google search "CTSV LS7 clutch" and you'll get LOTS of info about the intricacies of the job. There are even a couple threads that do a good job of summarizing all the tips and tricks you'll want to be aware of.
05-02-2014, 01:52 PM
#10
Its kind of hard to advise someone to swap out their stock clutch without knowing whats causing his dragging problem. He may spend the close to $1K all said and done only to find out his new LS7 is dragging because his stock MC is worn out... need to pinpoint the problem first, then take a course of action. maybe the pressure plate is failing and causing the drag. its hard to say and without pulling the transmission which is gonna be a tough egg to swallow if only for inspection purposes lol... if it were mine, id probably swap the MC first..
05-02-2014, 02:09 PM
#11
Doesn't sound like a clutch issue at all. It's either your master cylinder or your slave cylinder. If it was your clutch, all would be like normal except when you release the clutch to drive, it will not want to grab. Especially in the higher rpms you'll notice the rpms having a harder time dropping while upshifting
05-02-2014, 02:32 PM
#12
The checklist in the Service Manual for Clutch Drag is as follows:
Definition: The clutch does not disengage completely to allow smooth shift operations. It may cause gear clashing while the vehicle is not moving, at idle and shifting out of neutral, or hard shifting in and out of gears while driving vehicle.
1. Pedal blocked from full travel.
2. Too much travel between pedal and clutch master cylinder or worn pedal bushings.
3. Clutch pedal mounting loose.
4. Linkage at pedal worn or damaged.
5. Clutch master cylinder is seized or binding.
6. Air in clutch hydraulic system.
7. Clutch actuator (slave) cylinder seized or binding.
8. Clutch master cylinder leaking internally.
9. Damaged clutch assembly components. This includes damaged clutch disc, hub, splines, bent clutch disc, bent drive straps, broken or warped pressure plate.
10. Excessive side loading on the release bearing.
11. Faulty pilot bearing.
12. Transmission input shaft splines are worn or damaged.
13. Tight or contaminated clutch disc splines.
14. Flywheel housing, engine block to clutch housing, or transmission front case excessively misaligned.
15. Grease or oil contamination on the clutch disc facing.
16. Loose, broken, or faulty motor mounts.
Definition: The clutch does not disengage completely to allow smooth shift operations. It may cause gear clashing while the vehicle is not moving, at idle and shifting out of neutral, or hard shifting in and out of gears while driving vehicle.
1. Pedal blocked from full travel.
2. Too much travel between pedal and clutch master cylinder or worn pedal bushings.
3. Clutch pedal mounting loose.
4. Linkage at pedal worn or damaged.
5. Clutch master cylinder is seized or binding.
6. Air in clutch hydraulic system.
7. Clutch actuator (slave) cylinder seized or binding.
8. Clutch master cylinder leaking internally.
9. Damaged clutch assembly components. This includes damaged clutch disc, hub, splines, bent clutch disc, bent drive straps, broken or warped pressure plate.
10. Excessive side loading on the release bearing.
11. Faulty pilot bearing.
12. Transmission input shaft splines are worn or damaged.
13. Tight or contaminated clutch disc splines.
14. Flywheel housing, engine block to clutch housing, or transmission front case excessively misaligned.
15. Grease or oil contamination on the clutch disc facing.
16. Loose, broken, or faulty motor mounts.
05-02-2014, 04:39 PM
#14
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Is there a specific way I can test the master to ensure that could be the issue, or at least be part of the issue before I throw a 100 part at the car?
05-02-2014, 04:59 PM
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Doesn't sound like a clutch issue at all. It's either your master cylinder or your slave cylinder. If it was your clutch, all would be like normal except when you release the clutch to drive, it will not want to grab. Especially in the higher rpms you'll notice the rpms having a harder time dropping while upshifting
When I'm pressing it down, it seems once its at the floor, it just doesn't disengage. I was assuming this could be pressure plate still being moved or dragging. I'm glad to see another alternative, being that the MC could be going. I'd like a solid way to truly test if the MC is causing at least SOME of the issue, so I can get at it.
I'm familiar with the depressing clutch and seeing if fluid rises trick... i'd like something a bit more solid for proof.
MC should be an easier job than dropping the trans again.
05-02-2014, 05:36 PM
#18
If the master cylinder is defective it will not hold the clutch pedal reserve with repeated operation. The pedal reserve is the distance between the clutch pedal position when fully depressed and the clutch pedal position when the clutch causes the car to move when in gear. The test is usually done by blocking the wheels, placing the car in gear with the engine running and then repeatedly moving the clutch pedal from fully depressed to the point of vehicle movement. If the master cylinder is defective the amount of pedal reserve will gradually decrease to zero.
05-02-2014, 06:51 PM
#19
If the master cylinder is defective it will not hold the clutch pedal reserve with repeated operation. The pedal reserve is the distance between the clutch pedal position when fully depressed and the clutch pedal position when the clutch causes the car to move when in gear. The test is usually done by blocking the wheels, placing the car in gear with the engine running and then repeatedly moving the clutch pedal from fully depressed to the point of vehicle movement. If the master cylinder is defective the amount of pedal reserve will gradually decrease to zero.
