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Weird wear on clutch

DC_Gearhead

Sr. Member
Joined
Dec 28, 2015
Messages
660
Anyone know why my
clutch would wear unevenly like this. I’m doing an AX15 conversion and this caught my eye.

Also would you guys upgrade the pressure plate to the newer type if you were me? My kit came with a new centerforce clutch disc but not a new pressure plate.

0dbf5a49043bf638dec0577ae8b7b41b.jpg



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Broncobowsher

Total hack
Joined
Jun 4, 2002
Messages
37,064
I take it those wear marks match the back of the clutch fingers? Did it make any noise? Maybe when the clutch was completely on the floor?
The half moon shape makes me wonder if the disk might have got slightly bent during install?

What was the reason for taking this apart?
 
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DC_Gearhead

DC_Gearhead

Sr. Member
Joined
Dec 28, 2015
Messages
660
I’m just disassembling it now to put in the AX15. I saw that half moon wear when I pulled the old 3 speed off. I’m pulling the bell housing off this morning. I had never seen the 3 finger pressure plate before like this before.

That wear would be from rubbing on the throw out bearing right? Strange because throwout bearing didn’t have any strange wear like that.

I didn’t notice any strange behavior before I started my conversion so I’m confused.

Once I get it all apart I’ll take more pics.


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Bruners4

Full Member
Joined
Jul 22, 2019
Messages
282
Loc.
1/2 way to everywhere
It almost looks like the pressure plate fingers may have contacted the clutch disk. Will be able to check their backside after you have it apart.
 

Broncobowsher

Total hack
Joined
Jun 4, 2002
Messages
37,064
I’m just disassembling it now to put in the AX15. I saw that half moon wear when I pulled the old 3 speed off. I’m pulling the bell housing off this morning. I had never seen the 3 finger pressure plate before like this before.

That wear would be from rubbing on the throw out bearing right? Strange because throwout bearing didn’t have any strange wear like that.

I didn’t notice any strange behavior before I started my conversion so I’m confused.

Once I get it all apart I’ll take more pics.


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Not the throw out bearing contacting the disk, the back side of the fingers that the throw out bearing is pushing against.
If this is the old 3-speed that is coming out, not that worried about it.
 

Grey owl

Contributor
Sr. Member
Joined
Nov 19, 2024
Messages
395
That is for sure not normal, do not reassemble until the problem has been fixed. Its likely a pressure plate issue maybe broken springs,
 
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DC_Gearhead

DC_Gearhead

Sr. Member
Joined
Dec 28, 2015
Messages
660
Pictures of the pressure plate and clutch removed. The 3 fingers on the pressure plate are polished equally from rubbing on the clutch.

It looks like the clutch disc is bent just slightly.

I wasn’t planning on replacing the pressure plate, but what do you guys think?

ccca831377343cdba355c13d65f6f0a9.jpg

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e14f58ba438b9a7643bee52bfd9b2821.jpg

4bd18c1062c57cec75dde9e4f6159e4d.jpg



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jamesroney

Contributor
Bronco Guru
Joined
Sep 11, 2007
Messages
2,596
Loc.
Fremont, CA
Anyone know why my
clutch would wear unevenly like this. I’m doing an AX15 conversion and this caught my eye.

Also would you guys upgrade the pressure plate to the newer type if you were me? My kit came with a new centerforce clutch disc but not a new pressure plate.
Inadequate free-play, or lack of pedal stop at the top of the pedal results in over-travel at the bottom.

So the throwout bearing pushes the finger well past the release point, and further into the disc. That particular disc is not perfectly flat in the hub (and it doesn't need to be...) so it touches on the fattest finger at the tallest point. Your release bearing, and flywheel will look perfect.

I have some shorter friends that like the pedal to release right at the top. Also check your pedal to floor distance, and adjust the pedal stop.

I'd run it.
 
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DC_Gearhead

DC_Gearhead

Sr. Member
Joined
Dec 28, 2015
Messages
660
That makes perfect sense since the wear on the fingers was even and when I got it the clutch was really out of adjustment. I ended up putting in one if those Wilwood hydraulic actuators and a master. Works very smoothly now but I assume the damage was done.


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Broncobowsher

Total hack
Joined
Jun 4, 2002
Messages
37,064
Rare to find a used clutch that looks that good.
I would compare the profile of the new clutch disk to the old one.
I suspect that you will be fine reusing that pressure plate and flywheel. As mentioned, poorly adjusted linkage pushing the fingers in too far. Bent disk is typically letting the transmission hang while trying to install it. Looks like it had a recent clutch install from how good the parts look.

Good job checking and asking questions. I think the rest of the transmission swap will go well for you.

Slow typing. So there is a hydraulic clutch conversion done. I'm sure that is where the over stroke of the fingers into the disk came from. Now to fix that, couple of options. Move the master cylinder linkage pivot point on the clutch pedal slightly closer to the top (Pivot point) of the pedal, reduce the stroke going into the hydraulics. A slightly smaller master to move less fluid. Or a slightly larger slave to get less travel for the fluid moved. I don't know the disired travel of the clutch fingers, or the actual travel you are getting. So hard to do the math of what the best fix would be. Moving the pivot point on the pedal is pretty much a free fix, if the pedal geometry will allow it.
 
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DirtDonk

Contributor
Bronco Guru
Joined
Nov 3, 2003
Messages
51,616
Has anyone ever installed an AX15 with the Long (three finger) pressure plate/cover before?
Seems like every one I’ve read about was using a diaphragm style clutch.
Are there any clearance issues?

I liked both my original and McLeod replacement with the three finger. But I think we’ve read here that there are pedal travel issues with diaphragm style clutches that need to be adjusted out.
 

73azbronco

Contributor
Bronco Guru
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Nov 11, 2007
Messages
8,778
Clutch flywheel pressure plate look normal to me.


BUT, if you are in it and everything out, and going AX, yes, resurface the flywheel, install all new pressure plate clutch bearing, all of it.
 

ntsqd

heratic car camper
Joined
Jan 30, 2005
Messages
5,953
Loc.
Upper SoKA
It isn't always about how good or bad the parts look when considering their reuse. Sometimes it's all about how much work it is to get back in there to them. Clutches count as that. I'd put a new PP on that new clutch disc. Use the correct T/O bearing for the type of PP that you put in there, Change the pilot bearing/bushing, and you shouldn't need to think about any of it for quite a while.
 

Grey owl

Contributor
Sr. Member
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Nov 19, 2024
Messages
395
Its all apart now i would resurface the fly wheel and definitely replace the the pressure plate.
 

73azbronco

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Bronco Guru
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Messages
8,778
I would check the rear crank seal, why is there what appears oil or grease stains going from crank to flywheel surface?
 

Broncobowsher

Total hack
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Jun 4, 2002
Messages
37,064
I would check the rear crank seal, why is there what appears oil or grease stains going from crank to flywheel surface?
I saw that, but it looks like pilot bearing lube may have been slightly excessive on the last clutch job. I can't see a rear main doing that without making a huge mess on the front side. Although I would suggest pulling at least one flywheel bolt and making sure loctite (sealer) was used.
 
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DC_Gearhead

DC_Gearhead

Sr. Member
Joined
Dec 28, 2015
Messages
660
The rear seal looks fine. That’s just lube from the pilot bearing. The oil on the cover is from a leaking oil pan gasket. I replaced the pilot bearing, clutch, and throwout bearing but didn’t resurface the flywheel.

I rebuilt the Dana 20 which was a lot easier than I expected. I also rebuilt the driveshafts which was much harder than expected. I’m assembling everything this weekend so we’ll see how it goes.


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