Clutch Break-in
Thread Starter
Melting Slicks
Joined: Nov 2011
Posts: 2,789
Likes: 3
From: Jacksonville FL
Clutch Break-in
McLeod recommends 500 miles/1200 clutch cycles for proper break-in.
This is really like waving a bottle of Crown Royal in front of a recovering alcoholic. Especially when I was driving today for a little break-in time and had a MazdaSpeed 3 ricer pull up next to me. LOL
Anyway, just a couple questions for those who have been through this process:
Thanks!
This is really like waving a bottle of Crown Royal in front of a recovering alcoholic. Especially when I was driving today for a little break-in time and had a MazdaSpeed 3 ricer pull up next to me. LOL
Anyway, just a couple questions for those who have been through this process:
- Are 1200 cycles necessary? If not, how many?
- Is there any way to know or feel when the clutch has achieved break-in?
- Does it matter if traction control is on or off?
Thanks!
Drifting
Joined: Sep 2013
Posts: 1,943
Likes: 4
From: Lawrenceburg KY
I can't answer number 1 since I've never had a clutch fail due to insufficient break-in, but the answer for 2 and 3 are both "No." The clutch won't change in feel or sound at all and you shouldn't be running it hard enough to break traction so traction control being on or off shouldn't matter.
The main contributor to the break-in process is doing slow take-offs from a stop where you slip the clutch a little rather than spinning the tires.
The main contributor to the break-in process is doing slow take-offs from a stop where you slip the clutch a little rather than spinning the tires.
Race Director
Joined: Jan 2008
Posts: 16,028
Likes: 170
From: oregon
you can jump on it a bit, full blown drag racing may not be the best plan though, especially on sticky tires.
the cycling is to promote a perfect seat between the friction material and flywheel/pressureplate
a clutch will not hold capacity until it has properly broken in
but
if your clutch is WAY over capacity for the power you make it's probably harmless to get on it
the risk is the disc slipping under pressure and some materials not recovering well if they get glazed or drastically overheated
try to drive in as much city traffic as possible, that quickens the break in process
i think most manufacturers suggest this so a guy doesn't buy a 500/tq clutch and strap it to a 500/tq motor with slick, run to the strip and beat on it. when new the clutch would slip
car makers do this with engines too. the proper way to break in an engine is to quickly vary the rpm, idle to redline, up down, under vacuum, WOT repeat. however, some guys would probably get in the car and just hammer it in a high speed run which can promote excessive ring wear on a new hone. so, the car makers say drive the car easy the first 1000 miles
the cycling is to promote a perfect seat between the friction material and flywheel/pressureplate
a clutch will not hold capacity until it has properly broken in
but
if your clutch is WAY over capacity for the power you make it's probably harmless to get on it
the risk is the disc slipping under pressure and some materials not recovering well if they get glazed or drastically overheated
try to drive in as much city traffic as possible, that quickens the break in process
i think most manufacturers suggest this so a guy doesn't buy a 500/tq clutch and strap it to a 500/tq motor with slick, run to the strip and beat on it. when new the clutch would slip
car makers do this with engines too. the proper way to break in an engine is to quickly vary the rpm, idle to redline, up down, under vacuum, WOT repeat. however, some guys would probably get in the car and just hammer it in a high speed run which can promote excessive ring wear on a new hone. so, the car makers say drive the car easy the first 1000 miles
Last edited by racebum; Jan 12, 2014 at 07:15 PM.
Thread Starter
Melting Slicks
Joined: Nov 2011
Posts: 2,789
Likes: 3
From: Jacksonville FL
I can't answer number 1 since I've never had a clutch fail due to insufficient break-in, but the answer for 2 and 3 are both "No." The clutch won't change in feel or sound at all and you shouldn't be running it hard enough to break traction so traction control being on or off shouldn't matter.
The main contributor to the break-in process is doing slow take-offs from a stop where you slip the clutch a little rather than spinning the tires.
The main contributor to the break-in process is doing slow take-offs from a stop where you slip the clutch a little rather than spinning the tires.
Thread Starter
Melting Slicks
Joined: Nov 2011
Posts: 2,789
Likes: 3
From: Jacksonville FL
you can jump on it a bit, full blown drag racing may not be the best plan though, especially on sticky tires.
the cycling is to promote a perfect seat between the friction material and flywheel/pressureplate
a clutch will not hold capacity until it has properly broken in
but
if your clutch is WAY over capacity for the power you make it's probably harmless to get on it
the risk is the disc slipping under pressure and some materials not recovering well if they get glazed or drastically overheated
try to drive in as much city traffic as possible, that quickens the break in process
i think most manufacturers suggest this so a guy doesn't buy a 500/tq clutch and strap it to a 500/tq motor with slick, run to the strip and beat on it. when new the clutch would slip
car makers do this with engines too. the proper way to break in an engine is to quickly vary the rpm, idle to redline, up down, under vacuum, WOT repeat. however, some guys would probably get in the car and just hammer it in a high speed run which can promote excessive ring wear on a new hone. so, the car makers say drive the car easy the first 1000 miles
the cycling is to promote a perfect seat between the friction material and flywheel/pressureplate
a clutch will not hold capacity until it has properly broken in
but
if your clutch is WAY over capacity for the power you make it's probably harmless to get on it
the risk is the disc slipping under pressure and some materials not recovering well if they get glazed or drastically overheated
try to drive in as much city traffic as possible, that quickens the break in process
i think most manufacturers suggest this so a guy doesn't buy a 500/tq clutch and strap it to a 500/tq motor with slick, run to the strip and beat on it. when new the clutch would slip
car makers do this with engines too. the proper way to break in an engine is to quickly vary the rpm, idle to redline, up down, under vacuum, WOT repeat. however, some guys would probably get in the car and just hammer it in a high speed run which can promote excessive ring wear on a new hone. so, the car makers say drive the car easy the first 1000 miles
Drifting
Joined: Sep 2013
Posts: 1,943
Likes: 4
From: Lawrenceburg KY
I believe the reason is that with TC off, if you do accidentally launch it hard enough to spin the tires then the clutch will just fully engage quickly and spin the tires with relatively little stress on the clutch/driveline. If TC starts messing with stuff you can possibly end up with an extended period of rapidly loading/unloading on the clutch.
Thread Starter
Melting Slicks
Joined: Nov 2011
Posts: 2,789
Likes: 3
From: Jacksonville FL
I believe the reason is that with TC off, if you do accidentally launch it hard enough to spin the tires then the clutch will just fully engage quickly and spin the tires with relatively little stress on the clutch/driveline. If TC starts messing with stuff you can possibly end up with an extended period of rapidly loading/unloading on the clutch.
Thread Starter
Melting Slicks
Joined: Nov 2011
Posts: 2,789
Likes: 3
From: Jacksonville FL
Ok, one more question for you experts. Is 1200 cycles as good as 500 miles? Is it an either or thing? An approximation? I drove a 12-15 mile route today and had 133 shifts. If I did this 10 times it would be roughly 1330 shifts. Would that be an appropriate break in? I assume cycles mean shifts, or does cycles mean all the way up or down the gears? I assume not because in around town driving I'd rarely reach 5th and 6th gear.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Thread Starter
Melting Slicks
Joined: Nov 2011
Posts: 2,789
Likes: 3
From: Jacksonville FL
Ok, one more question for you experts. Is 1200 cycles as good as 500 miles? Is it an either or thing? An approximation? I drove a 12-15 mile route today and had 133 shifts. If I did this 10 times it would be roughly 1330 shifts. Would that be an appropriate break in? I assume cycles mean shifts, or does cycles mean all the way up or down the gears? I assume not because in around town driving I'd rarely reach 5th and 6th gear.
Thread Starter
Melting Slicks
Joined: Nov 2011
Posts: 2,789
Likes: 3
From: Jacksonville FL
I think I am going to do 1200 shifts and not worry about the mileage as much. My mileage will probably be around 250 when I do the 1200 shifts. This way I can break it in faster and get back to regular driving.