How stiff should pressure plate be?
#1
On The Tree
Thread Starter
How stiff should pressure plate be?
I've been having trouble with shifting my Camaro since I got it. Was hoping it was air in the line since the clutch has recently been replaced. Tried bleeding it out to no avail. I took it tea good local shop and ended up pulling the trans. He found that the pressure plate fingers are too stiff and the slave cylinder can't push on it hard enough to disengage the clutch. Everything is new and you can stand on the pressure plate and it won't budge the fingers. Will be replacing everything with a new clutch, pressure plate, flywheel, and slave cylinder. I don't know much about T56 trans and I'm just wondering how stiff the pressure plate should be? The guy at shop says it look like an aftermarket set that was in there and the stock stuff won't work it.
#3
FormerVendor
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This is probably the silliest post I've seen in a while...
You could stand on a stock clutch and not depress the diaphragm spring, the bearing load is around 400 lbs.
It sounds as if your mechanic is just plain uneducated in the workings of a clutch. You're using hydraulic pressure, it very much can depress the diaphragm spring of a clutch.
That said, did your mechanic measure the clearances on the setup to see if it needs a shim? What master is in it? If stock, is it in good shape? If an adjustable unit has it been adjusted correctly? Are you sure you've got all the air out of the system?
Give us some more info and we'll be more than happy to help...
You could stand on a stock clutch and not depress the diaphragm spring, the bearing load is around 400 lbs.
It sounds as if your mechanic is just plain uneducated in the workings of a clutch. You're using hydraulic pressure, it very much can depress the diaphragm spring of a clutch.
That said, did your mechanic measure the clearances on the setup to see if it needs a shim? What master is in it? If stock, is it in good shape? If an adjustable unit has it been adjusted correctly? Are you sure you've got all the air out of the system?
Give us some more info and we'll be more than happy to help...
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I've been having trouble with shifting my Camaro since I got it. Was hoping it was air in the line since the clutch has recently been replaced. Tried bleeding it out to no avail. I took it tea good local shop and ended up pulling the trans. He found that the pressure plate fingers are too stiff and the slave cylinder can't push on it hard enough to disengage the clutch. Everything is new and you can stand on the pressure plate and it won't budge the fingers. Will be replacing everything with a new clutch, pressure plate, flywheel, and slave cylinder. I don't know much about T56 trans and I'm just wondering how stiff the pressure plate should be? The guy at shop says it look like an aftermarket set that was in there and the stock stuff won't work it.
Hydraulics give you a mechanical advantage so that you can press on the pedal with, say, 40 pounds of pressure, and exert 500 pounds of pressure on the clutch at the slave. Same way your brakes work.
Is it possible that an aftermarket clutch was used and the stock hydraulics are not up to the task? Yes, 1000 times, yes. The stock hydraulics in a 4th gen are terrible - barely adequate for the stock clutch, and that's debatable. It's quite likely your clutch was replaced, because the hydraulics were failing, and the symptoms were misinterpreted.
It's also equally likely that the clutch needed to be shimmed when installed and wasn't, resulting in a gap between the slave and plate, which acts very much like you've got a ton of air in the line.
I agree with "black". Most likely, you need a new / upgraded master cylinder - even if you put a stock clutch back in the car. Since you are replacing everything else anyway, the master is cheap by comparison. Also, like "Black", I suggest a beefier aftermarket master like tick, ram, mccleod. I replaced my stock master with two stock masters before finally springing for the tick, and it was worth every penny.
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I just did a search for your username, and you have posted a few times for clutch-related stuff. I re-read all your threads, and I'm now becoming very convinced that the new clutch was installed without a shim and that is the root issue. One of your posts, you noted how light the pedal feels, which can mean air in line or a shim is needed. I just didn't make the connection before.
Also, given the age of the vehicle, the clutch master is likely in need of replacement.
Typically, when you get into a whole range of stuff on an F-body clutch, it ends up being a firesale - everything must go. The best way to fix it permanently is to replace the clutch and hydraulics in one fell swoop. Take measurements to make sure you don't need a shim. Since your clutch is basically new, you might be able to just measure everything and install a shim, improved master cylinder, and life is good.
Lastly, while the transmission is out of the car, FOR THE LOVE OF GOD, don't put the transmission back in without first installing the tick remote bleeder on the slave. It's $75 do be able to easily bleed the clutch from the driver's seat by yourself for the rest of your life!!!!!
Also, given the age of the vehicle, the clutch master is likely in need of replacement.
Typically, when you get into a whole range of stuff on an F-body clutch, it ends up being a firesale - everything must go. The best way to fix it permanently is to replace the clutch and hydraulics in one fell swoop. Take measurements to make sure you don't need a shim. Since your clutch is basically new, you might be able to just measure everything and install a shim, improved master cylinder, and life is good.
Lastly, while the transmission is out of the car, FOR THE LOVE OF GOD, don't put the transmission back in without first installing the tick remote bleeder on the slave. It's $75 do be able to easily bleed the clutch from the driver's seat by yourself for the rest of your life!!!!!