Reusing Centerforce PP while installing new disc - What prep needs to be done?

[5spd GT]

Well I want to reuse my pressure plate with a new disc and resurfaced flywheel. What can I do to the pressure plate to make sure it doesn't slip and grabs like it is supposed to and effectively.

Just clean it off with emory cloth or what?

Some say you can get the pressure plate resurfaced. That just doesn't seem natural to me Some say scrub it with grit paper to rough the surface up...I don't like that idea...

 

[5spd GT]

bump

 

[diablostang]

At least use some brake-cleaner on it.

 

[90mustangGT]

If it has any glazing on it then definatly scuff that off. Any hotspots, might as well replace it. Resurfacing the PP, I guess it could be done with the right equipment. I would definatly scuff it some to get a new surface.

 

[green]

i did that a few years ago with mine. the pp dident look to bad so i just threw it back together. never sliped yet.

 

[5spd GT]

When you say scuff it up...what do you suggest? I just feel a bit scared to scratch the pressure plate surface up with some grit when it came "stock" shiny and flat

 

[5spd GT]

bump

 

[5spd GT]

Any further help?

 

[SQUEEZE&STROKE]

Use some 1000 grit sandpaper (wet sand it using rubbing alcohal) to remove the hotspots...use a sanding block or similar tool to keef it nice and flat.

 

[Michael Yount]

You won't like the answer --- but I'd replace the pressure plate and the disc as a unit. I wouldn't take a chance with the old pressure plate.

I think a machine shop is gonna have a hard time doing anything with the plate disc unless you disassemble the pressure plate.

 

[5spd GT]

So I can get that at wallieworld? So would that effect performance.

How does a hotspot (besides visually) hurt the grabbing ability of the pressure plate?

 

[Michael Yount]

You might find the finer grits at WalMart - you may have to try Lowe's/Home Depot.

I believe I'd call Center Force's tech line and ask them about the surface prep requirements of the pres. plate face. Even with a sanding block, you won't be able to keep it flat/true -- except by dumb luck. And 1000-1200 grit is fine for polishing something -- but I'm guessing a polished pressure plate face isn't exactly what you're after for 'grab'. I'm sure there is a specific requirement for face finish and roughness -- akin to the machined surface they'll put on the pressure plate. But I'm pretty sure it's not the kind of micro-polished surface you're gonna get with 1000 grit paper or emery cloth.

Hot spots change the hardness of the local area that was affected. When the hardness is changed - the coefficient of friction is different. Different friction coefficients lead to grabbing -- and will also wear the clutch disc unevenly.

I think the worst case is that you end up having to go back in and replace the disc again, along with replacing the pressure plate anyway.

I believe this is an area where trying to save a few $ is gonna cost you more in the long run -- especially if it's been slipping due to being wet with oil.

 

[SQUEEZE&STROKE]

I only threw out the 1000grit as a suggestion to remove hot spots but when I did this...(By no means am I reccomending this!!!) I just hit it up with a die grinder and some smei fine sanding discs...has worked great for me...I hit up both the PP and the FW.

 

[5spd GT]

I'm going to fire off an email to Centerforce and see what they say...I'll report back

 

[Michael Yount]

I think that's a splendid idea!

 

[5spd GT]

Quote for quote from Brian at CF:

"I would recommend cleaning the pressure plate as good as possibly with some acetone to remove all the oil/grease. If you have excess to a sand/bead blaster I recommend to sand/bead blast the area that the disc rides on. Make sure you blow out all the sand as best as possible to ensure you will not have any operating difficulties.

Sincerely.
Brian Hankla
Tech Support
Centerforce Clutch"

 

[Michael Yount]

....not at all what I expected....sandblasting is about as inexact as it comes for ending up with a flat/true surface. I'm not sure your tech there knows what he's talking about David. I believe I'd use 60 grit sandpaper on a block in a random pattern instead of blasting it --- but that's just me.

 

[5spd GT]

....not at all what I expected....sandblasting is about as inexact as it comes for ending up with a flat/true surface. I'm not sure your tech there knows what he's talking about David. I believe I'd use 60 grit sandpaper on a block in a random pattern instead of blasting it --- but that's just me.

I understand your thoughts (honestly)

The pressure plate is bolted (pressed) against the disc while the clutch is engaged...I'm sure the ridges from the beading overcome the "non-flat surface" that is possible. I don't think you would bead it long enough to make any imperfections in the flatness.

He has been very helpful and always quick to reply everytime I have asked him a question. Probably my 5 or 6th one to him alone...

It makes sense, I think, but I don't have access to one. I'm probably going to clean it off really really good and look for visual damage and go from there.