Clutch Not Disengaging
Created by: Rosebud
Orig. Posting Date | User Name | Edit Date |
Jul 31, 2020 06:48AM | Dan Moffet | |
Jul 31, 2020 05:43AM | onetim | |
Jul 30, 2020 09:34PM | Rosebud | |
Jul 30, 2020 03:31AM | Dan Moffet | |
Jul 29, 2020 08:35PM | Rosebud | |
Jul 26, 2020 07:00PM | croc7 | Edited: Jul 26, 2020 07:04PM |
Jul 26, 2020 05:07PM | Rosebud | |
Jul 26, 2020 05:02PM | Rosebud | |
Jul 26, 2020 04:49PM | tsumini | |
Jul 24, 2020 08:34PM | croc7 | |
Jul 22, 2020 10:03PM | Spank | |
Jul 22, 2020 05:21PM | Rosebud | |
Jul 22, 2020 07:56AM | Rosebud | Edited: Jul 22, 2020 07:58AM |
Jul 22, 2020 04:27AM | Dan Moffet | |
Jul 21, 2020 03:41PM | 1963SV2 | |
Jul 21, 2020 01:49PM | Spank | |
Jul 21, 2020 12:03PM | Rosebud | Edited: Jul 23, 2020 07:11AM |
Jul 21, 2020 08:30AM | Spank | |
Jul 20, 2020 07:22PM | Rosebud | |
Jul 16, 2020 01:49PM | tsumini |
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Rosebud: I'm glad you got it sorted. It has been about 47 years since I did a Mini engine swap but I was thinking of the dogbone steady, which would have been undone for me. Then I thought about aftermarket steadies you may have, as well as the transmission front steady on my current Mini. Then I remembered my first Mini with an 850 or later an 1100, managed to snap a stock downpipe right at the elbow beside the diff, (boy, was that LOUD!) and it occurred to me that if the engine could put that much stress into a pipe, then jacking an engine for wok removal would do something similar.
.
"Hang on a minute lads....I've got a great idea."
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In my case removing the mount and lowering the wok end helped with the lower wok bolts.
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Quote:
Originally Posted by Dan Moffet
Have you tried disconnecting engine steadies and exhaust pipe? Lifting the engine for the work may have tweaked them.
Once I realigned and re-clamped the exhaust pipe, I re-connected the lower engine steady and began tightening it until the motor mount hole lined up. Thanks again.
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Have you tried disconnecting engine steadies and exhaust pipe? Lifting the engine for the work may have tweaked them.
.
"Hang on a minute lads....I've got a great idea."
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I installed the TO bearing, got the wok buttoned up, adjusted the clutch… blah, blah, blah. Here's my problem. When it came time to lower the left side of the motor onto the subframe and fasten the motor mounts, I discovered that the bolt holes on the mounts are a full inch away from the corresponding holes in the subframe. I expected they'd be misaligned a bit and thought I could massage them into place with a drift. I pulled and pushed on the floor jack trying to get them to line up, but couldn't budge the motor one bit.
Is this common? What's the solution, a big pry bar and try to muscle it into place? Of course, I would loosen the motor mounts on the right side, but still, the motor needs to move a lot. Aside from partially removing the engine and dropping it back into place, does anyone have another solution?
Is this common? What's the solution, a big pry bar and try to muscle it into place? Of course, I would loosen the motor mounts on the right side, but still, the motor needs to move a lot. Aside from partially removing the engine and dropping it back into place, does anyone have another solution?
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Not my personal experience. Got my info from a very informed gentleman from Australia on another forum when I was searching for a quality T/O bearing. Good luck, hope it works out for you.
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Quote:
Originally Posted by tsumini
Internet should have examples and info on failure modes race spalling, cage failure, misalignment etc.
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Quote:
Originally Posted by croc7
Not a good choice for a t/o bearing, sourced out of Korea, I think. A better choice is GRB201 or GRB0238HD.
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"Does anyone have a theory as to why my bearing failed at 20K miles? "
Close examination of the bearing may give some clues. Expert lab would be expensive (they could tell) but probably not worth it. I've examined quite a few bearing failures in previous life. Internet should have examples and info on failure modes race spalling, cage failure, misalignment etc.
Close examination of the bearing may give some clues. Expert lab would be expensive (they could tell) but probably not worth it. I've examined quite a few bearing failures in previous life. Internet should have examples and info on failure modes race spalling, cage failure, misalignment etc.
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Not a good choice for a t/o bearing, sourced out of Korea, I think. A better choice is GRB201 or GRB0238HD.
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You're just looking for / listening for an obvious "Thunk" or signs of movement. it's only a few thou normally, and if you get to the point were you can perceive it or hear it move rather positively, then THAT's when you've got a problem. No discernible movement, No problem.
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Quote:
Originally Posted by Spank
with that much damage, I would strongly advise you to see if you can discern any meaningfully end float in your crank. You can do this by pushing inward and pulling outward on your flywheel. With the starter removed, you should be able to do it by pushing ourward from starter hole and then pushing back inward from the removed wok cover side.
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Quote:
Originally Posted by Dan Moffet
This one?
Chichak on clutch
"Clutch pedals have a total movement of 4", which translates to a total slave cylinder thrust of 5/8". At a ratio of 5.33:1, this amounts to 0.117" of movement at the business end of the actuating arm, 0.069" of which is taken up by the adjustable stop, leaving only about 0.050" of useful thrust bearing movement. As will be shown later, anything less than 0.045" of clutch displacement will result in friction plate drag and difficulty in engaging gears. Thus, there is little room for wear in the system."
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Quote:
Originally Posted by 1963SV2
Somewhere on this site (I presume its still there) is Marcel Chichek's excellent article on setting up the clutch (make sure that diaphragm spring is "flat" when the clutch is bolted together) complete with graphs showing the relationship between clutch plate loading and displacement of the spring from its fully loaded position...
Cheers, Ian
Cheers, Ian
This one?
Chichak on clutch
.
"Hang on a minute lads....I've got a great idea."
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Somewhere on this site (I presume its still there) is Marcel Chichek's excellent article on setting up the clutch (make sure that diaphragm spring is "flat" when the clutch is bolted together) complete with graphs showing the relationship between clutch plate loading and displacement of the spring from its fully loaded position...
Cheers, Ian
Cheers, Ian
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That clutch diaphragm "pop over center" I'm speaking of is only set up at the time the backing plate is bolted to the flywheel straps with the diaphragm spring. The 3 horns or fingers of the backing plate and their length when the whole thing is sandwiched together with the clutch disc is what determines the preload of the clutch and whether or not you can come close to achieving that "pop over" point.
Bill Gilcrease of Mincomp clued me in to this and it's overall importance when he did my first clutch for me back in my first year or so of mini ownership.
Bill Gilcrease of Mincomp clued me in to this and it's overall importance when he did my first clutch for me back in my first year or so of mini ownership.
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Quote:
Originally Posted by Spank
When sitting at traffic lights with a foot on the clutch, one is simply forcing the flywheel and backing plate to remain open so the friction disc can free spin, and the throwout bearing is taking the full load of the diaphragm spring while trying to keep it open. A good practice to prevent throwout bearing wear is to put the transmission in neutral at stop lights and keep ones off the clutch pedal.
Having a poorly set up clutch diaphragm spring will magnify the side loading stresses. a clutch diaphram spring is (for lack of a better term) like a belleville washer and gets stiffer and stiffer as it is compressed until the point where it "pops" over-center and gets weaker.
Putting in a stronger spring that needed, like an orange, grey, or double-grey, makes it that much more force.
When sitting at traffic lights with a foot on the clutch, one is simply forcing the flywheel and backing plate to remain open so the friction disc can free spin, and the throwout bearing is taking the full load of the diaphragm spring while trying to keep it open. A good practice to prevent throwout bearing wear is to put the transmission in neutral at stop lights and keep ones off the clutch pedal.
Having a poorly set up clutch diaphragm spring will magnify the side loading stresses. a clutch diaphram spring is (for lack of a better term) like a belleville washer and gets stiffer and stiffer as it is compressed until the point where it "pops" over-center and gets weaker.
Putting in a stronger spring that needed, like an orange, grey, or double-grey, makes it that much more force.
I am by nature, very sympathetic to the mechanics of my car. In between shifts or when idling more than 3-5 seconds, my left foot is off the clutch and on the dead peddle. As a matter of fact, the photo of my dead peddle was taken the day I installed it. 10K miles later it's smooth and well-worn. And of course, I always start the engine in neutral with my foot off the clutch.
As soon as I discovered my throwout bearing had exploded, I called my engine builder (Seven Mini). Mike K said he was surprised that the throwout bearing lasted as long as did, given that I have an orange diaphragm. He said he always brings a bunch of bearing to the racetrack to feed his orange/gray diaphragm. Your experience with the orange diaphragm (and now mine) makes me think that when it's time to replace the clutch, I may opt for the blue, particularly since you said you've never had a slippage problem. I've got 90 HP, but I'm very gentle on the clutch; the left foot is (almost) always on the dead peddle before I nail the throttle. So, next time, blue it is. Thanks, everyone for your help.
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with that much damage, I would strongly advise you to see if you can discern any meaningfully end float in your crank. You can do this by pushing inward and pulling outward on your flywheel. With the starter removed, you should be able to do it by pushing ourward from starter hole and then pushing back inward from the removed wok cover side.
As for why that happened? Sometimes bearings just fail and are faulty.
Things I would consider that happened is that the owner was riding the clutch pedal while at stop lights and while idling, or the clutch was not fully releasing for some other reason causing the throwout bearing to spin constantly.
As has been said, that little gap in the clutch arm stop bolt is to ensure there is freeplay between the bearing and the diaphragm spring washer. The spring on the top of the clutch arm that attaches to the teardrop washer on the slave cylinder is to make sure that gap at the arm is pulled closed which ensures the gap between the bearing and the diaphragm spring is open. if you lose that top external coil spring on the slave, the gap inside the wok will bounce open and closed and that throwout bearing will spin.
When sitting at traffic lights with a foot on the clutch, one is simply forcing the flywheel and backing plate to remain open so the friction disc can free spin, and the throwout bearing is taking the full load of the diaphragm spring while trying to keep it open. A good practice to prevent throwout bearing wear is to put the transmission in neutral at stop lights and keep ones off the clutch pedal. Any time the car must be idled, it is not a terrible idea to leave the gear selector in neutral and foot off the clutch: The bearings at play while this is happening are all bathed in oil, which helps to keep them cooler than, say, a throwout bearing spinning at 1K rpm with over 100lbs of lateral force applied to it.
Having a poorly set up clutch diaphragm spring will magnify the side loading stresses. a clutch diaphram spring is (for lack of a better term) like a belleville washer and gets stiffer and stiffer as it is compressed until the point where it "pops" over-center and gets weaker. Ideally, the clutch is set up so that, when the clutch pedal is fully depressed, the diaphragm spring pops over center and is very light on the throwout bearing (and crank thrust washers). If the clutch spring never pops over center, the forces remain at peak while ones foot is on the clutch pedal. Putting in a stronger spring that needed, like an orange, grey, or double-grey, makes it that much more force.
I have raced (or had others race) my 90-something hp 1275 in endurance races, where there are at least 3 shifts every 3minutes and for 24 hours at a time, and I went away from an orange clutch diaphram spring after just 1 event and have used the blue spring exclusively for several hundred hours on the same clutch/flywheel setup and never, ever EVER had a problem with a slipping clutch, all the while using a tran-X clutch style lsd. I'm NOT saying those performance springs don't have their place, but their place is definitely NOT on a road car and arguable not on many race cars.
Not putting ANY blame on you Rosebud. I'm simply going through possible causes and things people who will read this later should consider. Like I said in the beginning... sometimes bearings just fail.
As for why that happened? Sometimes bearings just fail and are faulty.
Things I would consider that happened is that the owner was riding the clutch pedal while at stop lights and while idling, or the clutch was not fully releasing for some other reason causing the throwout bearing to spin constantly.
As has been said, that little gap in the clutch arm stop bolt is to ensure there is freeplay between the bearing and the diaphragm spring washer. The spring on the top of the clutch arm that attaches to the teardrop washer on the slave cylinder is to make sure that gap at the arm is pulled closed which ensures the gap between the bearing and the diaphragm spring is open. if you lose that top external coil spring on the slave, the gap inside the wok will bounce open and closed and that throwout bearing will spin.
When sitting at traffic lights with a foot on the clutch, one is simply forcing the flywheel and backing plate to remain open so the friction disc can free spin, and the throwout bearing is taking the full load of the diaphragm spring while trying to keep it open. A good practice to prevent throwout bearing wear is to put the transmission in neutral at stop lights and keep ones off the clutch pedal. Any time the car must be idled, it is not a terrible idea to leave the gear selector in neutral and foot off the clutch: The bearings at play while this is happening are all bathed in oil, which helps to keep them cooler than, say, a throwout bearing spinning at 1K rpm with over 100lbs of lateral force applied to it.
Having a poorly set up clutch diaphragm spring will magnify the side loading stresses. a clutch diaphram spring is (for lack of a better term) like a belleville washer and gets stiffer and stiffer as it is compressed until the point where it "pops" over-center and gets weaker. Ideally, the clutch is set up so that, when the clutch pedal is fully depressed, the diaphragm spring pops over center and is very light on the throwout bearing (and crank thrust washers). If the clutch spring never pops over center, the forces remain at peak while ones foot is on the clutch pedal. Putting in a stronger spring that needed, like an orange, grey, or double-grey, makes it that much more force.
I have raced (or had others race) my 90-something hp 1275 in endurance races, where there are at least 3 shifts every 3minutes and for 24 hours at a time, and I went away from an orange clutch diaphram spring after just 1 event and have used the blue spring exclusively for several hundred hours on the same clutch/flywheel setup and never, ever EVER had a problem with a slipping clutch, all the while using a tran-X clutch style lsd. I'm NOT saying those performance springs don't have their place, but their place is definitely NOT on a road car and arguable not on many race cars.
Not putting ANY blame on you Rosebud. I'm simply going through possible causes and things people who will read this later should consider. Like I said in the beginning... sometimes bearings just fail.
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Quote:
Originally Posted by 1963SV2
Originally Posted by 1963SV2
My bet is that it has something to do with the release bearing... Your symptoms are consistent with a collapsed bearing (BTDT as well ) ....or maybe damage to the release bearing seat that sits in the middle the diaphragm.
Quote:
Originally Posted by Spank
Those allen key bolts that it looks like you have are going to make your life pretty miserable when it comes to trying to remove the wok cover while the engine is in the car.
Quote:
Originally Posted by CooperTune
I saw where the new style throw out bearing had worn deeply into the diaphragm thrust plate.
Originally Posted by jedduh01
Wrench for the bottom Clutch Wok bolts. Reaches around the Subframe for the bottom 2= Priceless…
Quote:
Originally Posted by Spank
Those allen key bolts that it looks like you have are going to make your life pretty miserable when it comes to trying to remove the wok cover while the engine is in the car.
Quote:
Originally Posted by CooperTune
I saw where the new style throw out bearing had worn deeply into the diaphragm thrust plate.
Originally Posted by jedduh01
Wrench for the bottom Clutch Wok bolts. Reaches around the Subframe for the bottom 2= Priceless…
Besides a new throw-out bearing, can anyone think of anything else I might need? CooperTune mentioned a deeply worn diaphragm thrust plate. Here's a shot of (I think) my thrust plate. It has some wear marks, but there's no ridges or scoring. Does it look OK? Can anyone recommend the "heavy-duty" type bearing? [link]
Does anyone have a theory as to why my bearing failed at 20K miles?
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Quote:
Originally Posted by Rosebud
Quote:
Originally Posted by Minimike1
with all this talking, you could have removed the clutch cover by now and seen inside to diagnose what's happening. Get to it brother.