This is a short video of me chasing Alan Goodall in his Alfa 75 - at Sandown this morning.
http://www.youtube.com/watch?v=G9T-9asqTao
jim ~
What broke Jim? You went home early.....
Seriously fast Jim, nice work.
I broke the clutch again - well, sorta, because now that I have taken the gearbox out (again..) it appears likely that the problem was really caused by a fitting error on my part. I am going to cut a hole in the clutch bell housing so that I can see when the clutch forks are engaged with the release bearing.. the car has a pull clutch and you cannot see when the engagement ears on the bearing are in the forks. By the looks of the release bearing the forks were pulling on the wrong part of the bearing - and came off, causing the bent bits that you can see in the photo. At least I am getting quicker at removing the clutch.
jim,..
Quote from: jimnielsen on May 31, 2010, 04:42:11 PM
I broke the clutch again - well, sorta, because now that I have taken the gearbox out (again..) it appears likely that the problem was really caused by a fitting error on my part. I am going to cut a hole in the clutch bell housing so that I can see when the clutch forks are engaged with the release bearing.. the car has a pull clutch and you cannot see when the engagement ears on the bearing are in the forks. By the looks of the release bearing the forks were pulling on the wrong part of the bearing - and came off, causing the bent bits that you can see in the photo. At least I am getting quicker at removing the clutch.
jim,..
Usually with those style of clutch, the bearing comes in two parts, and you have to clip them them together yourself. The reason why, is you put the other bit onto the clutch fork while the gearbox is on the bench, then once you've fitted the gearbox to the car, give the fork a good shove in the opposite direction to the way it would normally go to clip the bearing in...
yes, that's how they come alright, however you can't get the release bearing off the pressure plate fingers after that process has been completed, making it a tad more difficult on 2nd and 3rd installations....
Shame. Car looked good until then.
Quote from: jimnielsen on May 31, 2010, 07:06:55 PM
yes, that's how they come alright, however you can't get the release bearing off the pressure plate fingers after that process has been completed, making it a tad more difficult on 2nd and 3rd installations....
Hi Jim
Don't try and install the gearbox like that.
You can get the bearing off the fingers by removing the pressure plate and squeezing up the "spring flange" (I can't think of anything else to call it :-[ ) part of the bearing on the inside.
Quote from: SteveNZ on June 01, 2010, 12:00:01 AM
Quote from: jimnielsen on May 31, 2010, 07:06:55 PM
yes, that's how they come alright, however you can't get the release bearing off the pressure plate fingers after that process has been completed, making it a tad more difficult on 2nd and 3rd installations....
Hi Jim
Don't try and install the gearbox like that.
You can get the bearing off the fingers by removing the pressure plate and squeezing up the "spring flange" (I can't think of anything else to call it :-[ ) part of the bearing on the inside.
Usually called a snap ring, I think. And yes, you can seperate the thrust bearing again by doing this. Small flat blade screwdriver, and a few inches of wire out of the mig welder to keep the ring compressed as you work around it. Don't forget to reposition the triangular plastic sleeve back over the snap ring to assist in refitting...
Didn't realise you hadn't replaced the pressure plate when you fitted the fancy new friction plate...
Well, from those Ideas, I was able to get the release bearing out. Unfortunately, I had been listening to all the people who said that it could not be done..that didn't help!
Anyway, after a while you can do it in just a few seconds, but you have to know how.. I have made a brief video of the process for the curious!
http://www.youtube.com/watch?v=4ud5bY0EZxA
This was using an old bearing/pressure plate that I had around..
However, I practically had the gearbox bolted up to the engine again already before this.. using a pressure plate with the bearing still attached. So all I really had to do was to make absolutely sure that I got the proper engagement between the clutch "forks" and the bearing - so I used ClutchCam (tm) for that purpose..
http://www.youtube.com/watch?v=EJt7HxPSmxc
This video wont mean anything to anyone really, but it does show the forks captive in the place in the bearing where it is supposed to be!
But next time i would simply remove the release bearing and install it on the forks, as if it was a new install, clutchcam can still be handy though, because its quite a job to reinstall the clutch just to fix errors..
I have added data to the video
http://www.youtube.com/watch?v=9b9PbrOGmds
Jim,
Thanks for making the video on how to remove the bearing from the pressure plate. Excellent work.
Love clutch cam. I can see your in this time. Good for peace of mind when your casually travelling over 200 k and you have to change gear, in a real hurry!!!
Now I'll have to buy a car with a pull clutch, just to give it go myself.
Frank
I can't see the justification for these "pull clutches", Frank - they are too much of a nuisance - and for what benefit? The clutch is so light that when I first got the car I thought that the clutch wasn't actually working! You have to be careful that you have a stop under the clutch pedal at the correct place or else you can damage the pressure plate..
anyway, I installed the new slave cylinder today (pic) - no problems - most of the old one is still somewhere near the exit to turn one at Sandown..
Jim, and I think Frank will confirm this that is an alfa sud unit. mmm might be the best part of the car. lol.
Ah yes, Good call Ray, looks identical to the Alfa sud unit. I'm not surprised, we know how good they are, the rest are just trying to keep up.
Now Jim, a soft clutch was designed with the Ladies in mind wasn't it ??? You've got power steering as well haven't you. What going on here!!! Can you take me shopping at Phillip Island, I know it will be a very quick trip.
Seriously though, I would like to know what the engineering is for this design.
For example, I have notice that the thrust bearing on a push clutch causes the fingers of the diaphram spring to wear so thin they collapse. Usually attributed to resting your foot on the clutch pedal constantly.???
Maybe its cheaper to produce??? Clutches aint clutches is seems.
Frank,
Alfa checked this out and I'm told, and it was only a problem on right hand drive cars, the wheel well on the left makes a decent footrest compared to the tiny one on our right hand drive ones? But to be fair I have worked in Alfa Warranty and remember the phrase "Commercially Acceptable" being used on more than a few occasions. How many clutches have you worn the fingers out on? I'm currently on number four and the third clutch fork, but the gearbox I had fitted when I bought my car is still pretty good.
Andrew
Andrew,
I have never had an Alfa clutch fail on a car that I was driving, though have bought a few suds/33 not going to use as spares for the race car, and on two suds I have found the problem of the fingers collapsed where the thrust race contacts. Bloody nasty. On one I found the clutch plate was in very good condition, which made me think that only the clutch plate was changed?? I stuff around with my cars too much so they never even get close to that stage of wear.
In the race car I used to run a 3 puck?, solid center, looks like cintered brass?? clutch plate with the original pressure plate. This was sort of good, plenty of grip, no slip, BUT, get the gear change wrong, and extremely harsh on the transaxle. So after breaking 2 tranny's in six months, I replaced it with the original clutch plate. Grouse.
I removed it before the Mallala 6 hr, last month, just as a precaution because I could hear a rattle. So I found that the 4 springs that I think are use to dampen, where not tight, slight loose, so I put it back.
The pressure & clutch plate came from the white 86 Sprint which I began sprinting seven years ago,(R.I.P), so its bloody good!
What do you mean, four clutches and three forks, Surely not from the same car?
Last clutch in 33, had 6 of the 18 'Fingers' or 'Prongs' of pressure plate worn completely through. This is a year or two after I bought it. Only clue was the thrust bearing was making a small amount of noise when the clutch was pedal was depressed. Lining still had plenty of meat, the thrust race bearings just age then start to drag on pressure plate fingers. Noise it made wasn't that bad considering it was close to letting go...Glad I didn't put it off any longer!
Frank,
Bought car with a stuffed gearbox gearbox and put one in when I put a reco box as I did not want to pull it out again, then I had an issue with the clutch pedal pivot wearing out and the pedal missing the stop so it was pushing the clutch too far and collapsed the thrust race which cost me two by breaking the spring fingers due to me not noticing it when I changed a clutch.
May of been due to slave cylinder leaking and it not extending fully at the time. That one only lasted a year because shortly after I replaced the slave cylinder and with good hydraulics it and a worn pedal and I remember sitting at the lights when the pedal sunk to the floor as the fingers bent and it started to creep forward.
I gave the car to Bruno that time (I had the shits with it) and he fixed the pedal for me, repairing the fork and used a Valeo clutch which is still going strong and is much nicer to use than the ZF one I had used previously. so now I have a lovely smooth one and good slave cylinder. Bruno did say he had never seen one that bad that was still driving, so to date the only time the car has stopped moving under its own power since I got it going was when I ran out of fuel 50 yards from a servo on a steep hill, my own fault/lazyness.
Strangely enough I still have never worn out a friction plate just the fingers on the pressure plate. This is my fault because I drive to and from work in large steel capped boots in traffic so I know I ride the clutch as I can't feel a thing in them and cannot use the footrest.
Philpot,
Thanks for taking the time to post the photo. Thats what I have seen. Spot on. For a second I thought you have been in my garage because it's virtually identical, a failed pressure plate with a very good clutch plate.
Andrew,
I know what you mean about the boots. I hate wearing them so I actually put my runners on when I drive to work and then put the boots on. I also have the habit of pushing the brake at the same time as the clutch when I'm attempting flat changes through traffic (with boots on), wakes me up in the mornings!
Cheers