It is pretty easy to do a 'file test' on these parts to see if they are sup-par, but I suspect the problem here is down to a combination of dirt ingress causing a grinding-paste style effect, and a part that isn't as good as it could be.

I load the cavity above the ball up with grease, and smooth it over on top to make a 'barrier'. Occasionally, I'll scoop out the old grease and pack some fresh stuff in there. I am using 'factory' parts however - and will never throw servicable factory units away as they are sooo much better than the aftermaket ones.

Do you need the clutch arm from Pixie? I had put my name on it early, but if you believe you need it, you can take it.

Mark Looman, Ada Michigan 1967 Austin Cooper S

Mark, the weird thing is that there is no wear on the arm, clevis pins, holes in the wok, MC to pedal holes, etc.  It's all in the plunger.  I suspected an inferior part, but the place I got the plunger from 4 years ago say they've never seen anything like it.

And an adjustable pushrod was what kept it working with the old plunger.  Now the new one's looking like it's doing the same thing.  BTW, did you get those old hinges yet?

willy

Mark Looman, Ada Michigan 1967 Austin Cooper S

Kristina

DON'T feed the trolls

I installed the "uprated" arm at the same time as the first plunger.  Had a verto clutch with a leaking clutch seal, decided to swap it all over to a pre-verto clutch setup, so everything was new 10,000 miles ago.  Then the rebuild of the engine came, and had a new plunger installed.

I'll try finding an older clutch arm.  I think pixieracing had one for sale in one of his posts.  The clutch arm is way easier to change out than the plunger.

willy

Maybe I'm missing the core of the problem, but I hope this helps.

Mark Looman, Ada Michigan 1967 Austin Cooper S

That's pretty bad wear considering the low mileage. The one I removed didn't have anywhere near that kind of wear.

I was thinking more about the metal compatibility issue and I think I might modify my response. It could very likely be the clutch arm that is the culprit and not the plungers.  Did you replace the clutch arm and the plunger at the same time (during the first plunger replacement)? Either part could cause this problem if the hardness isn't matched properly. MM used to carry two different arms, the original "thin" one and the uprated heavy duty one. They no longer carry the original one and the description has changed on the uprated one leaving out the "heavy duty" part. It could be that the uprated one is not only thicker but of a slightly stronger steel and is causing the problem. see the link below...

http://www.minimania.com/web/Item/22A2204/AddedFrom/CatBrowse%2D%20CLUTCH/InvDetail.cfm

If you could find a used arm in servicable condition you could try it for a while and see if the condition persists. If it does then you know it's the plunger, if it stops then you know it's the arm and you can go from there. Either way you should get the answer you need through the process of elimination. (and I'll start to worry about the plunger and uprated arm I installed last year)    dan

"I don't know much, but what I do know I know little of "

That's probably correct, Dan.  I did buy the 2nd one from the same supplier, about 4 years apart.  Just guessing, it's probably getting worse and I don't remember having to adjust the first one this soon (<1000 miles).  Here's the picture of the old one with less than 10,000 miles on it.

willy

SE7EN

Did you buy the 2nd plunger from the same supplier? I ask because I keep thinking about the Chinese aftermarket parts (and others out there) and their questionable quality. If the plunger is made of a softer metal (mild steel vs harder alloys) or not heat treated to the same hardness as the clutch arm ball then you can experience this kind of wear even if greased.

I've read a lot of posts since I joined this board regarding inferior parts (like layshafts) due to heat treatment or metalurgy issues. It's only logical that this can spill over to less critical parts for our minis'.

The only experience I have in all this is when I replaced  a plunger, arm, pins and slave cylinder and I noticed no unusual wear except on the ball end of the arm. I would assume that this is the normal wear point and since yours is wearing on the plunger it is the anomoly.

It seems like the only commonality is the identical wear on two new plungers and no wear to the ball. I saw the question regarding the competition clutch assembly and I wonder if people who run them experience this kind of wear. If not then I would try to find a supplier that buys parts from a different source for the next one and see what happens.

Just thinking out of the box.  dan

"I don't know much, but what I do know I know little of "

The nuts are there, I do not sit at lights with the pedal depressed.  The plunger is actually wearing out where the clutch arm "digs" into it.  I need to take a photo of my old one and post it up.  This new one is doing the same after < 1000 miles.

willy

Yeah, that is the right side up. Do you still have the over throw nuts on the back end? Are they well clear of the cover when the clutch pedal is depressed? I am trying to figure out why you are not getting full throw to release the clutch.

The only other thing that I can think of is that your crank taper has been over lapped and the whole clutch/flywheel assembly is sitting too far back. Let us hope that isn't the case.

Terry 

If you're not on the edge............ you're taking up to much space.

It's installed this "side" up.

Hey Willy, maybe the plunger has been rotated 180 degrees and your not getting full throw.

Terry 

If you're not on the edge............ you're taking up to much space.

You know, I've thought of that.  But when I bought it it was supposed to be the stock everyday one.  It did seem a little heavier than the verto clutch I replaced.  But c'mon, after less than 1000 milkes????

I took the arm out last night and the ball end looked nice and round.  Wiped off the grease and looked into the plunger hole with a mirror and I can already see it's getting worn into the side.  I adjusted the stop bolt (about 3 full turns) and the clutch engaged 3/4 off the floor (near the top).  Well, after a 5 mile drive to work, it now engages 1/4 off the floor. 

willy

SE7EN

The ball on the end of the arm actually looked great, and it's not bent.  The clevis pins are all new, too. 

I need to get the kids to bed and pull the arm off to check out the ball end.  I wonder if it has a rough edge on it that's cutting into the plunger. 

willy

Mark Looman, Ada Michigan 1967 Austin Cooper S

The ball and socket was greased about 40 days ago when I installed the engine. 

Neal, I think you mean adjustable pushrod, right?  I already have that and it's been readjusted back to stock length after the rebuild.  When I dropped off the engine, the angle of the clutch arm was so far off "normal" that the engine builder immediately pointed at it and said, "Wow, that's not right."

willy