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View Full Version : Clutch 'sticking' after launch



vrmm
11-28-2014, 10:38 PM
After almost 2k miles on my stage 4 rr clutch install I tried a wet launch. While shifting into second (in neutral) it is almost like I put the brakes on. I'm not sure if it could be said that it just isn't fully disengaging. It's more like it's stuck to the flywheel or something of the sort... Idk

Comp 5456 28-30psi

It handles the power perfectly otherwise.

ricekikr
11-29-2014, 02:24 AM
Bleed.

vrmm
11-29-2014, 02:48 AM
I'll give it a shot. I've bled it probably 25 times on 3 separate occasions in the last 500 miles.

ricekikr
11-29-2014, 07:04 AM
If bled properly then works for a while, points to master/slave seal problem.

Does it still disengage (ie can you still shift gears)? If you cant and there's pressure on the clutch pedal, you could've welded the clutch.

vrmm
11-29-2014, 08:27 AM
I can't say that it was working before and now it's not since it's the first time I've tried launching. Without launching shifting works just fine. It's the same as it has been.

andyrew
11-29-2014, 08:42 AM
You try a vacuum bleeder?

vrmm
11-29-2014, 09:28 AM
No I haven't. I can see if I can borrow one. The fluid in it is pretty generic dot 4. Not sure if that can play a role in my issue.

ricekikr
11-29-2014, 04:11 PM
Could you elaborate more. List it step by step.

Bleed:
Launch (1st gear)
Shift to 2nd wont go in and car slows down dramatically?
But without launchin car shifts perfectly?

Other: tune etc.
Or after launching it will still shift to 2nd but slows down after shifting while still WOT?

walky_talky20
11-29-2014, 07:41 PM
^This. Be specific about what is happening.

From your description it sounds like you are getting heavy engine braking while the shifter is in the Neutral position. I don't think that's actually possible without a broken transmission, so please be more detailed in your explanation/order of events.

vrmm
11-30-2014, 12:41 AM
I've noticed since I installed the clutch that when engaging into second, low rpms seem 'heavy'. Once I get over 1200 or so it will act naturally. I don't know how to describe it very well.. kind of like a steady bog without shudder or hesitation. Perhaps that's just the effect of having a lwfw?

Anyways, the launch.. I don't hang rpms just rev and pop at 6k. It holds it extremely well/doesn't slip. I launched a few times today on dry asphalt and cement and I can say once the clutch is depressed, until I release it in second, my momentum/engine drops drastically. Like 3x more than just letting off the gas at any speed. I don't know what else to say about it. I can't really wrap my head around it.

vrmm
11-30-2014, 12:44 AM
Ohh and also if I didn't mention it in this thread shifting into second at high rpms is somewhat difficult. It takes a second to go in. I swapped slave cylinders and bled with no change to that. I've just been assuming my syncros are bad.ish

ricekikr
11-30-2014, 02:42 AM
I've noticed since I installed the clutch that when engaging into second, low rpms seem 'heavy'. Once I get over 1200 or so it will act naturally. I don't know how to describe it very well.. kind of like a steady bog without shudder or hesitation. Perhaps that's just the effect of having a lwfw?


Possibly tune/engine related. Need more info like afr/timing etc logs.



Ohh and also if I didn't mention it in this thread shifting into second at high rpms is somewhat difficult. It takes a second to go in. I swapped slave cylinders and bled with no change to that. I've just been assuming my syncros are bad.ish

At low rpm do you have any difficulty shifting (all gears)? Any grinding.

walky_talky20
11-30-2014, 09:54 AM
Ah, the engine revs are diving quickly. I would say the reason for this is two-fold:

1 - your clutch switch is working. You are getting immediate fuel cut when lifting the accelerator and depressing the clutch.
2 - Your flywheel is light. It will lose revs faster than a stock unit. What makes the revs come up faster also makes them come down faster.

A 3rd contributor could be thick oil. If you are running 20w50, the revs will dive quicker than if you run 0w20. You should probably not run either of those and stick with 5w40.

A possible workaround for you would be a "no lift shift" feature, which would have the engine find the revs for the next gear automagically (or at least keep them up in the vicinity of what you want). You could potentially retain the boost into the next gear as well.

andyrew
11-30-2014, 11:02 AM
Give us a video showing the boost guage and RPM while hard shifting.

Are you sure your not spinning in first and then grabbing 2nd to early? I know that its really hard to judge when to shift to second when your spinning the tires.. The Comp turbo doesnt spool up that fast and thus lag is GOING to happen when shifting like this. I know I have basically the same size turbo...

M-Hood
12-01-2014, 12:56 PM
I've noticed since I installed the clutch that when engaging into second, low rpms seem 'heavy'. Once I get over 1200 or so it will act naturally. I don't know how to describe it very well.. kind of like a steady bog without shudder or hesitation. Perhaps that's just the effect of having a lwfw?

Anyways, the launch.. I don't hang rpms just rev and pop at 6k. It holds it extremely well/doesn't slip. I launched a few times today on dry asphalt and cement and I can say once the clutch is depressed, until I release it in second, my momentum/engine drops drastically. Like 3x more than just letting off the gas at any speed. I don't know what else to say about it. I can't really wrap my head around it.


So kind of acting like as if you are going into a much higher gear, do you have full traction in 1st gear when you shift into 2nd gear?

vrmm
12-01-2014, 11:28 PM
I have 5-30 so nothing ludicrous. I could definitely see how no lift shift would help. I'm out of town, so it'll be a week or so before I can get a video. I'm not completely sure it will show the issue well, but I'll give it a shot.

When I shift into 2nd by the time it actually goes in gear I have traction.

It feels like it's in a lot higher gear when I have the under 1200rpm issue. During a launch it feels more like the brakes come on/it gets dragged down.

M-Hood
12-02-2014, 07:24 AM
I have 5-30 so nothing ludicrous. I could definitely see how no lift shift would help. I'm out of town, so it'll be a week or so before I can get a video. I'm not completely sure it will show the issue well, but I'll give it a shot.

When I shift into 2nd by the time it actually goes in gear I have traction.

It feels like it's in a lot higher gear when I have the under 1200rpm issue. During a launch it feels more like the brakes come on/it gets dragged down.

Could be that the brakes are coming on if the EDL is kicking on for some reason, which happens when 1 wheel is spinning more then any other while under 45 mph. Might need to check to see if you have a bad ABS. You can also unplug the ABS harness completely and see if the issue goes away.


During a launch, if you are spinning all 4 tires you pretty much have to ride it out or feather the throttle till you get full traction and then shift into 2nd gear. If you change gears while spinning all 4 tires the wheel speed will be too slow when you get traction in 2nd gear which will put you at a much lower rpm. So basically while spinning all 4 tires your actual speed is not matching your wheel speed, grab 2nd gear and the engine will have to bog down to match the actual speed of the car.

walky_talky20
12-02-2014, 03:49 PM
So just tap it off the limiter until it grabs then, yeah? lol

In for video...[drive]

M-Hood
12-02-2014, 04:31 PM
So just tap it off the limiter until it grabs then, yeah? lol

In for video...[drive]

I usually just back pedal the throttle 1 time and that usually ends up getting me traction once I am back on the throttle.

Just treat it like a FWD car that isn't getting traction. lol



If the tires are just spinning like crazy with the car going a whole 15-20 mph, grabbing 2nd gear at that point isn't going to get the car going again very quickly, 15-20mph in 2nd gear on a 1.8t 01A is 1800-2400 rpm. Talk about falling on its face.

vrmm
12-13-2014, 06:40 PM
There's 4k resolution. My phones camera looks like crap regardless...
Anyways.. You can tell it doesn't have much traction in first. I'm pretty sure Mike was right and I wasn't riding out first.
You can also tell how annoyingly long it takes to get into second. It's gotten quite a bit better since I put the clutch in, so hopefully it will keep getting better.


https://www.youtube.com/watch?v=F3Rpo71ThEs&list=UUKZfhsP0pMj6hipPgGNSGfw

I want a bigger turbo :p

vrmm
12-14-2014, 08:32 PM
A bit better video
I did notice something odd today. After I had my foot all the way off the clutch pedal it seemed to either drop down half way or it actually stayed half way disengaged. It didn't slip or anything. It was just odd.

http://youtu.be/OyPNsFGFl8o

andyrew
12-15-2014, 10:42 AM
Honestly looks like your delaying on putting the throttle back on until after you've completely let go of the clutch, also it seems like your taking your time shifting.

It looks like its driver error regarding your lag. Have you tried just letting off the gas just enough to shift? Your shifts look like there taking a second and a half, or at least thats what it looks like the time between when you let off the gas and put it back on..

Try throwing it in second the instant you touch the clutch, and touch the clutch the instant you step off the gas, then as stepping off the clutch (Not after) mash your gas again. Since your turbo does have some lag (especially more noticeable in first) your not going to burn your clutch as the engine starts building boost again.

This is obviously for WOT all out runs, for back country road whatever, a nice easy shift is fine for keeping a healthy clutch and trani.

Also this is a pretty decent sized turbo, you will notice SOME lag when shifting unless you have antilag or do no lift shifts.

andyrew
12-15-2014, 10:45 AM
https://www.youtube.com/watch?v=JglEI7LqLP8

Example of quick shifting. Granted this is an S4, but you can see how quick shifting should be.

vrmm
12-15-2014, 10:54 AM
It does take a small eternity to shift. It just does not like to go into second during a launch or just a normal pull. I've never had the issue in any other car or on this until I put my new clutch in. It's only second gear. I will try the magic you speak off and see if it helps any.

I do have a 4mm spacer in my slave rod. Engagement is almost at the very top. I do try to shift immediately after touching the clutch. It just really doesn't want to do it.

vrmm
12-15-2014, 10:59 AM
I don't think i could ever do what's in that video. I have to force it in even with the clutch in 100% even when I let my car slow down. It seems like he kinda rev matches it maybe with a little clutch?

andyrew
12-15-2014, 12:48 PM
Yes I believe the fastest way to shift if rev match.

You might want to check out your shift linkage to see if the bushings are worn.

The other option is that your 1-2 syncro is really worn and needs to be replaced. If you rev match 1-2 will it go in faster or do you physically have to just wait a second for it to slip in? Describe the shifting feeling.

Also have you ever changed your trani fluid?

M-Hood
12-15-2014, 12:50 PM
Honestly looks like your delaying on putting the throttle back on until after you've completely let go of the clutch, also it seems like your taking your time shifting.

It looks like its driver error regarding your lag. Have you tried just letting off the gas just enough to shift? Your shifts look like there taking a second and a half, or at least thats what it looks like the time between when you let off the gas and put it back on..

Try throwing it in second the instant you touch the clutch, and touch the clutch the instant you step off the gas, then as stepping off the clutch (Not after) mash your gas again. Since your turbo does have some lag (especially more noticeable in first) your not going to burn your clutch as the engine starts building boost again.

This is obviously for WOT all out runs, for back country road whatever, a nice easy shift is fine for keeping a healthy clutch and trani.

Also this is a pretty decent sized turbo, you will notice SOME lag when shifting unless you have antilag or do no lift shifts.

The trick to shifting fast is actually moving the shifter out of gear right as you push the pedal or just a split second before, don't need the clutch disengaged to take it out of gear.

vrmm
12-15-2014, 01:06 PM
Well... I've read clutch drag kills syncros and the whole issue with my pp bolts backing out led to about 1k+ of clutch drag. To the point I had to turn the car off to get into first in order to move again. I've been thinking that's the biggest issue. I'm not sure what shifter bushings you are specifically talking about given that I've never even looked into them, but there was quite a bit of play in all the linkage when I pulled my transmission. The rubber ball cup thing, 5 or so inches under that shift knob, is eaten apart really bad.