Clutch Engagement Issue
Clutch Engagement Issue After searching ls1tech and google i cant seem to find an answer to my specific problem. I recently installed a new flywheel and oem clutch kit. When i press the pedal to the floor to start the car i hear a grinding noise, and any other time the pedal is pressed i hear this noise. The pp bolts were torqued to 22 ft/lbs. A little background on my car: It was originally a 3.4 t5 and has been swapped to lt1 t56. The car is a 94 and the engine and transmission were both also out of a 94. Any help or suggestions on how to fix this would be awesome!
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Joined: Oct 2008
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From: Rochester, NY
This grinding noise happens when the car is running right? Doesn't matter if the tranny is in gear or neutral?
If that's the case, than it's probably a bad throwout or pilot bearing. You might have to pull the tranny to get a good enough look to make a diagnosis.
While the engine is turning and the clutch is engaged, the throwout bearing is spinning with the pressure plate but its not under any load. Also, since the friction disk is spinning at the same rate as the pressure plate, that means the pilot bearing isn't even spinning at all.
On the other hand, as long as the engine is on and turning and you push the clutch pedal to disengage it, it makes both bearings really work. The throwout bearing is under load from the clutchfork pushing on it, and the disks are spinning at different rates which means the pilot bearing will be spinning.
This is why when bearings start to go bad, they only make noise when the clutch pedal is pushed, most of the time.
If that's the case, than it's probably a bad throwout or pilot bearing. You might have to pull the tranny to get a good enough look to make a diagnosis.
While the engine is turning and the clutch is engaged, the throwout bearing is spinning with the pressure plate but its not under any load. Also, since the friction disk is spinning at the same rate as the pressure plate, that means the pilot bearing isn't even spinning at all.
On the other hand, as long as the engine is on and turning and you push the clutch pedal to disengage it, it makes both bearings really work. The throwout bearing is under load from the clutchfork pushing on it, and the disks are spinning at different rates which means the pilot bearing will be spinning.
This is why when bearings start to go bad, they only make noise when the clutch pedal is pushed, most of the time.
Yes, the grinding noise happens while the car is running and in neutral. I have not tested it in gear as this is a completely rebuilt engine from bottom to top and its not quite ready to go out on the road (no tags, or exhaust). I also installed a new throwout and pilot bearing, I do have one of each extra laying around. i figured i would eventually end up pulling the trans to see whats going on in there. Will definitely check those two things first after its out.
Ok, after pulling the transmission and looking for the problem with the grinding it wasn't the throwout bearing or the pilot, but instead the clutch fork itself was making contact with the pressure plate when the pedal was pressed to the floor. So, after clearancing the fork a little, and replacing a cracked freeze plug behind the flywheel, reinstalling flywheel clutch and all the slave cylinder decided to fall apart. Replaced it and the master cylinder bled the system, and now the car will not go into any gear other than 1st or 2nd while its running. if the car is off, it will slide into any gear. while its running its like there is no pressure that i got before to slide over to reverse but it wont even grind if you try and put it in, the gate is completely closed. Any help from anyone is much appreciated.
Edit: The trans would go through all gears before smoothly, with no issues at it just had that pesky tapping and grinding from the fork to the outside of the pressure plate.
Edit: The trans would go through all gears before smoothly, with no issues at it just had that pesky tapping and grinding from the fork to the outside of the pressure plate.
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Registered User
Joined: May 2012
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From: Oklahoma
I have a 97 T-56 formula and i had the SAME problem. Push in the clutch and about halfway engaged it would grind the motor to a stop. turns the little bracket that goes over the clutch fork was bent too far out by myself and there fore letting it bounce around in between the P-plate and tranny. I also tried to drive the car as long as possible like this and ruined the transmission. 1595 to have it rebuilt runs good!
Pulled it all back out today, found nothing wrong or out of place. Put it all back together, started it up and now it goes into all gears while running. reverse is a little stiff to get into still, but it was fine before any clutch parts were swapped/replaced. Took the car for a test drive for the first time in 2 years... extremely long swap/build... front end floats a little with alignment off quite a bit, the speedometer is way off but the rpms appear to be right on, and it doesnt seem to want to go into 3rd gear. It went on the ride back to the house but i had to shove pretty hard at about 3800rpm?
Recap: Any suggestions for reverse being a little stiff, speedometer being way off, and 3rd gear not engaging like it should.
I know the speedometer thing isnt really a clutch issue, but any help or suggestions with it would be awesome. Thanks again in advance guys
Recap: Any suggestions for reverse being a little stiff, speedometer being way off, and 3rd gear not engaging like it should.
I know the speedometer thing isnt really a clutch issue, but any help or suggestions with it would be awesome. Thanks again in advance guys
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Joined: Apr 2008
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So, after clearancing the fork a little, and replacing a cracked freeze plug behind the flywheel, reinstalling flywheel clutch and all the slave cylinder decided to fall apart. Replaced it and the master cylinder bled the system, and now the car will not go into any gear other than 1st or 2nd while its running. if the car is off, it will slide into any gear. while its running its like there is no pressure that i got before to slide over to reverse but it wont even grind if you try and put it in, the gate is completely closed. Any help from anyone is much appreciated.
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2. you replaced the slave....and still hard to get in gear....you need to continue to bleed the system. these hydraulics come sealed so are not meant to bleed and often is difficult to completely bleed once they have been opened (replace slave). a mighty vac seems to work.
3. if after bleeding reverse is still hard confirm reverse lock out solonoid is wired/working
4. also you do need to have the plastic cup on end of slave piston. new the slave comes "straped" and when you use the clutch 1st time it breaks strap leaving cup on piston.
5. when putting fork back on TO bearing do it with tranny about 1/4"-1/2" out as it slides on easier then push tranny the rest of the way in.
hope this helps
Like said, you should never have to clearance the fork. That would just be an indirect way of dealing with a another issue all together, which is never recommended...
I feel like you might not have the PP completely bolted up to the flywheel. There should be no space between the PP and the flywheel when correctly bolted up. I see people making this mistake (as I have) because they tighten the bolts until they say 22ft lbs and think that it is good when it is not, because it is not completely bolted together. This would cause all types of issues, like for instance a grinding throw out bearing, hard to get into gears, vibrations while driving... This could very well be the reason for your hydraulics acting all funky too..
Just throwing that out there. I may be wrong. Just something to consider. But I would definitely not drive it until you get to the bottom of this and fix it..
I feel like you might not have the PP completely bolted up to the flywheel. There should be no space between the PP and the flywheel when correctly bolted up. I see people making this mistake (as I have) because they tighten the bolts until they say 22ft lbs and think that it is good when it is not, because it is not completely bolted together. This would cause all types of issues, like for instance a grinding throw out bearing, hard to get into gears, vibrations while driving... This could very well be the reason for your hydraulics acting all funky too..
Just throwing that out there. I may be wrong. Just something to consider. But I would definitely not drive it until you get to the bottom of this and fix it..
I clearanced the fork just for good measure while checking out some other things while changing the slave cylinder. Most likely I only took out an 1/8" probably less. The first thing I looked for on the fork was for it to be bent or mis-shaped, but nada. I worked on bleeding the system after both hydraulic assemblies were replaced for about an hour, and had no more air bubbles coming to the resevoir of any kind. The Plastic cup is still on the end of the slave, i made sure to hold onto it. Lastly, the fork went in about those same situations as you suggested, Thanks ******! I also made sure that the pressure plate was making all the contact it could at 22lbs with the flywheel, there was no space between it and the flywheel (FormulaJoe). Any other suggestions guys? I really appreciate all the help and input
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Joined: Oct 2008
Posts: 492
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From: Rochester, NY
Where in the pedal throw is the clutch starting to engage? About halfway up? Or is it engaging right off the floor? If the clutch is engaging around where it should, than your problem with 3rd and reverse are tranny related. If your clutch is engaging way early, than you've probably still got a problem with your hydraulics.
Wouldn't bother with a Mity Vac, LT1 clutches are pretty easy to bleed as long as you have someone with you to watch the reservoir while you compress and release the slave cylinder repeatedly.
Wouldn't bother with a Mity Vac, LT1 clutches are pretty easy to bleed as long as you have someone with you to watch the reservoir while you compress and release the slave cylinder repeatedly.
I actually haven't checked where the clutch is starting to engage. I'll be sure to check that tomorrow as the car is still over at the shop. I'm not really sure what to think since I didn't have problems going into gear until after the slave cylinder went bad. No, I didn't even consider a Mity Vac, it seemed the best method was to pump the slave by hand while having someone else watch for air in the reservoir.
If it helps trouble shoot any of the problems, the trans is completely stock to my knowledge, the clutch is a stock replacement. The engine has had mild work done to it its been decked, mild head work, cc502, matched valve train with 1.6 rockers, stock replacement pistons, stock crank, new flywheel and clutch as stated earlier... everything in the engine is either brand new, been to the machine shop, or both.
If
If it helps trouble shoot any of the problems, the trans is completely stock to my knowledge, the clutch is a stock replacement. The engine has had mild work done to it its been decked, mild head work, cc502, matched valve train with 1.6 rockers, stock replacement pistons, stock crank, new flywheel and clutch as stated earlier... everything in the engine is either brand new, been to the machine shop, or both.
If
The clutch is engaging right off the floor... I am a little skeptical about it being a trans issue with this problem not existing until after the slave and master install. Any other help or suggestions guys?
TECH Regular
Joined: Oct 2008
Posts: 492
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From: Rochester, NY
Sounds like you've still got some air in the system.
When you pump the slave cylinder, make sure you tip the rod end downward and the opposite end with the high pressure line upward so any bubbles can move upwards more freely.
Not much advice, but its all I can think of now. The master and slave are brand new, so they can be ruled out. The stock fork, which is practically indestructable, is obviously not bent and is tightened down to the transmission properly. Not a whole lot of variables left.
When you pump the slave cylinder, make sure you tip the rod end downward and the opposite end with the high pressure line upward so any bubbles can move upwards more freely.
Not much advice, but its all I can think of now. The master and slave are brand new, so they can be ruled out. The stock fork, which is practically indestructable, is obviously not bent and is tightened down to the transmission properly. Not a whole lot of variables left.
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Joined: Oct 2008
Posts: 492
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From: Rochester, NY
What kind of clutch are you running? Is it an OEM style clutch?
Sometimes the beefier aftermarket clutches need an adjustable MC in order to be disengaged all the way, stock hydraulics won't always cut it.
Sometimes the beefier aftermarket clutches need an adjustable MC in order to be disengaged all the way, stock hydraulics won't always cut it.
I know i'm running out of ideas myself. I've come to terms with the syncros for 3rd possibly going bad, but reverse was working great. Would a little bit of air in the system allow all gears to engage smoothly except 3rd and reverse? I don't know a whole lot at all about this style trans. It is an oem clutch, I wish i would've upgraded to something else though. I haven't driven the car since Sunday when I took it out for a test ride, but it went into all gears except 3rd... i could shift through the gate into 3rd but when i would try to let pressure of the clutch pedal it would kick it out of that gear.