Centerforce clutch break-in?
Thread Starter
Racer
Joined: Feb 2009
Posts: 265
Likes: 0
Centerforce clutch break-in?
Installed a centerforce clutch on my '71 427 sb. Instruction sheet says: "All centerforce clutches require a break-in period of 450-500 miles of stop and go street driving before applying full engine power. This period is required to properly seat the disc with the pressure plate and flywheel."
I never heard of a break-in for a clutch before. Is this really necessary? That's going to take the whole summer with as much as it gets driven! Any experiences? Thanks.
I never heard of a break-in for a clutch before. Is this really necessary? That's going to take the whole summer with as much as it gets driven! Any experiences? Thanks.
Melting Slicks
Joined: Feb 2001
Posts: 3,330
Likes: 13
From: Europe , Luxembourg
Hi
Wow, 500 miles .
When I installed the DF Ctr force clutch, I did not care about this.
But I also resurfaced the flywheel.
I found the grip of the clutch to be excellent right away.
Then again, I don't race the care, so don't do launches starting at 5000 RPM. But when I feel like stepping the gas, I do so regardles.
Don't worry too much. Try it and you will feel if it grips correctly.
Rgds. Günther
Wow, 500 miles .
When I installed the DF Ctr force clutch, I did not care about this.
But I also resurfaced the flywheel.
I found the grip of the clutch to be excellent right away.
Then again, I don't race the care, so don't do launches starting at 5000 RPM. But when I feel like stepping the gas, I do so regardles.
Don't worry too much. Try it and you will feel if it grips correctly.
Rgds. Günther
Le Mans Master
Joined: Dec 2003
Posts: 5,727
Likes: 38
From: Fremont CA
I find you have to stay on top of the pedal "free play" adjustment for up to 3K miles before it settles down for the long term. If you don't keep the free play adjustment proper, the clutch will seem fine at low RPM but when the counterweights move the Bellville spring rearward at high RPMs you will unload and burn up the disc pretty quickly. You need 1-1.5" of freeplay in the linkage before the throw out bearing contacts the clutch fork to allow for the counterweight action of a CF clutch. Free play is easy to check, grab the linkage by the "Z" bar and watch the action of the linkage you want the clutch rod to have 1-1.5" of movement. I have also had to use a 1/2 heigth nut on the clutch linkage to allow for enough initial freeplay adjustment on one installation with a aftermarket bellhousing. The 1/2 heigth nut (a nylon locknut) was on the front side and I used 2 nuts at the rear to lock the clutch linkage adjustment. If they are broken in correctly CF clutches will live a long life.
Le Mans Master
Joined: Jan 2006
Posts: 6,506
Likes: 139
From: Butler Pa
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
All they are really worried about is you glazing the surfaces. Just like brake pad break in.
Your little motor probably isn't strong enough to hurt anything unless you slip the clutch under power
Your little motor probably isn't strong enough to hurt anything unless you slip the clutch under power
Thread Starter
Racer
Joined: Feb 2009
Posts: 265
Likes: 0
I resurfaced my flywheel too. I'll probably start jumpin' out on it then and see how she does. Thanks.
Thread Starter
Racer
Joined: Feb 2009
Posts: 265
Likes: 0
Thread Starter
Racer
Joined: Feb 2009
Posts: 265
Likes: 0
I find you have to stay on top of the pedal "free play" adjustment for up to 3K miles before it settles down for the long term. If you don't keep the free play adjustment proper, the clutch will seem fine at low RPM but when the counterweights move the Bellville spring rearward at high RPMs you will unload and burn up the disc pretty quickly. You need 1-1.5" of freeplay in the linkage before the throw out bearing contacts the clutch fork to allow for the counterweight action of a CF clutch. Free play is easy to check, grab the linkage by the "Z" bar and watch the action of the linkage you want the clutch rod to have 1-1.5" of movement. I have also had to use a 1/2 heigth nut on the clutch linkage to allow for enough initial freeplay adjustment on one installation with a aftermarket bellhousing. The 1/2 heigth nut (a nylon locknut) was on the front side and I used 2 nuts at the rear to lock the clutch linkage adjustment. If they are broken in correctly CF clutches will live a long life.
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Verdad Gallardo
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
Over the years I've broken a bunch of stuff on my poor old Vette. So a high rpm dump the clutch is not on my "smarter things to do" list
Slipping the clutch with your foot on the gas is even worse
I usually just off idle let the clutch out fast and then ease into flooring it with slicks. I use my motor TQ to go. Your 427 should be the same. To take off fast takes practise because my tires want to spin from a dead stop.
Slipping the clutch with your foot on the gas is even worseI usually just off idle let the clutch out fast and then ease into flooring it with slicks. I use my motor TQ to go. Your 427 should be the same. To take off fast takes practise because my tires want to spin from a dead stop.
Race Director
Joined: Dec 1999
Posts: 19,610
Likes: 778
From: Forked River NJ
I doubt you are going to hurt the clutch doing this but other parts tend to break.
I took those fricken little useless weights off the pressure plate anyway. They do nothing but make noise. Advertising hype.
Burning Brakes
Joined: Dec 2007
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Le Mans Master
Joined: Dec 2003
Posts: 5,727
Likes: 38
From: Fremont CA
Think long and hard about what is going on: as the disc wears, the pressure ring moves FORWARD towards the flywheel, as the ring moves forward, the bellville spring moves REARWARD thereby REDUCING clearance to the throw-out bearing. If you don't keep freeplay adjusted, the spring will bend backwards at high RPM and unload the clutch disc at the worst possible time. The 1-1.5" of freeplay is the movement of the clutch pedal not the rod, if you don't have 1-1.5 inches of freeplay with a CF clutch, you will have high RPM problems. My clutch pedal moves over 5" in travel maybe the other poster should remove his **** carpet from the 70's along with the velour upholstery and get something nicer in his Vette if he can't get 1-1.5" of free play in the clutch pedal.
Thread Starter
Racer
Joined: Feb 2009
Posts: 265
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[QUOTE=Solid LT1;1569535808]Think long and hard about what is going on: as the disc wears, the pressure ring moves FORWARD towards the flywheel, as the ring moves forward, the bellville spring moves REARWARD thereby REDUCING clearance to the throw-out bearing. If you don't keep freeplay adjusted, the spring will bend backwards at high RPM and unload the clutch disc at the worst possible time.
Now it makes sense- don't recall anything in the instructions with it about that. I need to increase the freeplay as it wears not decrease it like w/ a normal clutch. Thanks.
Now it makes sense- don't recall anything in the instructions with it about that. I need to increase the freeplay as it wears not decrease it like w/ a normal clutch. Thanks.
Le Mans Master
Joined: Jan 2006
Posts: 6,506
Likes: 139
From: Butler Pa
Maybe you should be a little more careful when you type your posts. Pedal freeplay is not the same as linkage freeplay.
