jdbaugh1

iTrader: (1)

Alright so I am still having trouble getting the car in gear for high RPM shifts though the clutch feels normal as far as it's release point and disengagement. I supposed it's still possible it is dragging somewhat. As an experiment, while sitting still, I revved up the car in neutral then pushed in the clutch and tried to put it in gear quickly. When I did this the car would inch forward as the synchros hit before allowing me to slip into gear. As I have never tested my transmission in this fashion I am thinking that indicates that the clutch is dragging somewhat though I honestly don't know if the mass of the clutch plus whatever is spinning in the transmission when in neutral is enough to cause this by itself after a 5-6k rpm rev in neutral.

I suppose the only thing I can really try is to bleed my clutch again. I don't know what vacuum bleeder I would need or where I could get one that will work with my car so I am thinking about rigging up my AC vacuum pump though I have no idea how much vacuum typical bleeders actually pull. Anyone have any idea? I don't want to overdo it and collapse my brake fluid reservoir or something silly like that.

Also, when using a vacuum bleeder what is the procedure? Do you just hook it up to the reservoir and let it chooch?

jdbaugh1

iTrader: (1)

https://www.jackstransmissions.com/p...kills-synchros

Found this article though it is not about Cobalts in particular it seems to agree that my clutch is dragging. If anyone could give me anymore information on vacuum bleeding the clutch I would appreciate it.

ECaulk

iTrader: (6)

Get mitivac, get a rubber stopper that fits in the brake resivour, pull -20inHg on the system, wait 10-15mins, release vacuum, pump clutch slowly a few times, and repeat.

jdbaugh1

iTrader: (1)

Hey thanks. If I can pull that much vacuum I think I can fabricobble a rubber stopper up and us my AC system vacuum pump.

Henry3959

Sounds like a bad pressure plate design. They are designed to apply more pressure with rpm's. If it wasn't changed then that may be ruled out. If you keep trying to shift it like this you will destroy the synchronizers.

jdbaugh1

iTrader: (1)

It was changed. It is the plate that came with the clutch. O7blackG5 should be using the exact same setup and he revs high RPM as well. That is why I went with this setup because I thought it was proven with his setup which is similar. Wonder if he is, in fact, using this same pressure plate. If he is then I would say it isn't the design but maybe faulty? Is that a thing? I still have my old one but man if I can avoid it I really don't want to drop the transmission again. Hopefully bleeding the clutch more will do the trick.

Henry3959

Put it in first gear on level ground and see if it tries to creep forward at idle with the clutch in. Then rev it with the clutch in and see if it tries to creep forward while in first.

jdbaugh1

iTrader: (1)

I'm fairly confident it will. But will that tell me if it isn't fully disengaging because of TOB travel or just a shitty pressure plate? It could still be either I would think.

jdbaugh1

iTrader: (1)

I have no intention of trying to keep shifting with this condition and am fully aware of potential to damage the synchros. I am obviously trying to correct this issue.

Henry3959

If it doesnt drag at idle i would say it is bled and it is the pressure plate

jdbaugh1

iTrader: (1)

Don't really know what to do if this is the case. Aren't aftermarket pressure plates designed for use with specific clutches? As in they apply different clamping force? I can't just throw on my previous pressure plate can I?

jdbaugh1

iTrader: (1)

So when revving the car with the clutch pushed in but with the transmission in 1st gear the car will start to pull forward at about 7k RPM accompanied by the smell of burning clutch. So I guess I am going to try like hell to bleed the system and then I can either drop the trans again right away or finish out the autocross season by shifting from 1st to second at low RPM as after I shift into second it stays there for the duration of the run.

jdbaugh1

iTrader: (1)

07blackg5 has an identical transmission/clutch/pressure plate setup and he also revs to 8K with no issues so if the problem is my pressure plate it isn't necessarily because of the design though I may have got a lemon.

cluelessk

Aren't these things infamous for being difficult to bleed?

Henry3959

In a net build system where there is no adjustments that can be made to increase or decrease travel, the pressure plate and clutch thickness have to be closely matched. I am sure that is watched anyway with the available aftermarket parts.

Henry3959

That isn't the result you wanted to see... That sounds like the pressure plate is flexing where it shouldn't be. Again... If it doesn't do it at idle, and there are no travel adjustments to be made, the hydraulic side appears to be bled.

jdbaugh1

iTrader: (1)

I'm about tired of getting shitty parts right out of the box that I paid good money for. Let's hope that isn't the case. Because I honestly don't know what I would do. Get another pressure plate from ClutchMasters and see if a new one will work, waste another $600 on a new clutch/pressure plate, or throw in my old clutch and risk it slipping and being back at square one.

Henry3959

Here's the diagnostics if you want to look at what they recommend.

jdbaugh1

iTrader: (1)

I'm still hoping I have a bit of air in there that is preventing correct TOB engagement. This is backed up by the last time I tried to bleed the clutch again the problem improved vastly, almost to the point where I thought it was gone completely. If there was a little air in there still it could be enough to cause this issue.

I have the day off tomorrow and I am going to mess around with rigging up a vacuum pump and see what that does.

T-Man

iTrader: (3)

You sir, need one of these

https://www.motiveproducts.com

jdbaugh1

iTrader: (1)

Which one? Will one of the cheaper units do the trick?

ECaulk

iTrader: (6)

Have used that to bleed the clutch? I've used mine to do the brakes but not for a clutch.

jd you want to get the chevy one, it's worth it and you can make more frequent brake fluid changes for the auto-x you do

T-Man

iTrader: (3)

Yep, as you know, it's a common reservoir. I bleed my clutch every oil change. Cheap insurance that I've carried over from my LSx days.

T-Man

iTrader: (3)

You need the GM unit with a 3 tab reservoir cap.

Edit -

This one
https://www.motiveproducts.com/colle...c-bleeder-kits

ECaulk

iTrader: (6)

I'm going to have to do this next oil change. Or next time I get under the hood.