stangs-R-me 121 Report post Posted March 18, 2011 My stock Ford O.E. replacement clutch & PP (installed mid 80's) is finally getting tired as I've been noticing slippage if I get on the throttle. Back in the day if you wanted a "guarenteed" chatter free clutch, one from your local Ford dealer was the only way to go. Clutch technology has come a long way since then and I've been real happy with Centerforce on late model Mustangs so I checked out what they had to offer for my 351W. From all that I read on CF's web site & a few vendors it appears that their replacements are in fact Diaphram types rather than the OE old-school "3-Finger Long" style. Before starting this post I did do a "Centerforce" search and read all the related threads which confirmed that it is in fact a Diaphram type and cetainly sounds like it is the way to go provided the upper pedal spring is removed. Reduced pedal effort and less stress on linkage will certainly be nice !! Anyway, my question is this ... CF II vs. Dual Friction The DF is only 25% more in cost and sounds like the way to go. I'm just curious if there are any benefits to going with the CF-II or is the DF superior in every way ?? My 351W: 0.030 over Forged TRW pistons (pump gas friendly 9.5:1 cr), P&P stock heads w/ screw-in studs/guide plates/hardened pushrods, Crower Hi-Perf Hyd cam, Offy 360 Equa-Flow intake, Holley 4150 600 CFM Double Pumper, Mallory Unilite Distributor, ported factory exh-mflds. & stock '69 BB 2.25" exhaust. Rest of drivetrain consists of a Wide Ratio Top Loader w/'70 Hurst Linkage, 9" 3.50 T-Lok, & 225/70-14 BFG Radial T/A's. Thanks, Doug Quote Share this post Link to post Share on other sites
Crazyhorse 21 Report post Posted March 18, 2011 I have the dual friction in the bronco with a warm 351 SEFI roller motor and love it in there. My wife's only problem with it is it has no slippage, you can't feather it out, as it grabs as son as it starts to engage. It's not really a problem when you have enough torque to engage that way though... Quote Share this post Link to post Share on other sites
LindenBruce 27 Report post Posted March 19, 2011 I had the DF in a 3/4 ton 4x4 truck and it was just great for that application. The DF is meant for heavy duty applications under tow/haul situations to help eliminate any slippage during shifts. For a passenger car application the CF II is probably a better clutch. Bruce Quote Share this post Link to post Share on other sites
Fordrevhead 29 Report post Posted March 19, 2011 I agree, unless you have a torquey big block the DF is not the way to go. My friend had one in his 67 coupe with a 390 top loader. I drove it one night when he had a few too many beers, and it worked well with that but very truck-like in the driveway and at low speeds. I could see how it would be great for towing! Quote Share this post Link to post Share on other sites
stangs-R-me 121 Report post Posted March 19, 2011 Thanks everyone for the personal experiences in various applications ... can't ask for better responces than that !! You'd think the Centerforce web site would help steer you toward the right clutch, but their write ups on the two sound about the same. The CF-I is only $8 cheaper than the CF-II (@ Summit) ... since I was perfectly happy with the stock Ford clutch all these years and my engine build would be considered "mild" would this maybe be even better for me ?? "The Centerforce I is designed as a high-quality entry-level performance clutch for those in need of a superior stock replacement. Using the patented Centerforce centrifugal weights (where applicable) and premium friction materials, the Centerforce Stage 1 clutch system is perfect for applications with stock engines or mild power increases from minor bolt-on modifications." vs. "The Centerforce II system utilizes a full facing-disc with premium friction materials and a pressure plate with patented centrifugal weights (where applicable). Furthermore, static clamp load is increased via their patented machining processes; this combination allows superb holding power and maximum clutch life, making this stage ideal for selected street/strip, off-road and towing applications." I suppose since they both use the same clutch disc, we're probably talking just more clamping force with the CF-II not a smooth vs. chattering issue. I'm guessing that the CF-II will probably even have a lighter "pedal feel" than the old-school factory clutch. Thanks, Doug Quote Share this post Link to post Share on other sites
sportsroof69 13 Report post Posted March 20, 2011 I have the DF in my car, and it's great. I have never had a complaint about it engaging too abruptly. It's nice and smooth, with no chatter, and holds well. I highly recommend it. Quote Share this post Link to post Share on other sites
Burn 14 Report post Posted March 20, 2011 I have the DF in my car, and it's great. I have never had a complaint about it engaging too abruptly. It's nice and smooth, with no chatter, and holds well. I highly recommend it. Ditto! Doug, I'm also using a DF and its been Great!!! I've had no chattering, no engaging issues and it holds great. I drive in a lot of stop and go traffic and I always ease into it from a complete stop without any issues. When I romp on it...it holds and my engine is similar to yours. I recommend it too. Quote Share this post Link to post Share on other sites
Burn 14 Report post Posted March 20, 2011 Also, Pedal feel with the DF (with no assist spring) is light and easy. Quote Share this post Link to post Share on other sites
Crazyhorse 21 Report post Posted March 22, 2011 I have the DF in my car, and it's great. I have never had a complaint about it engaging too abruptly. It's nice and smooth, with no chatter, and holds well. I highly recommend it. I didn't mean to suggest that I was dissatisfied with the Dual friction. I was just trying to describe it's engagement feel in the application I currently have it in. It will engage strong enough to light off both rear 38.5" tall tires on the bronco, and if you get on it good after the tires hook, it'll attempt to pull the front tires, all without any slippage. When I get to that point in my Mustang it will definitely be getting the same 11" dual friction clutch... Quote Share this post Link to post Share on other sites
coz 108 Report post Posted March 22, 2011 Whatever way you go make sure to pull the centering spring (assist spring). I left mine in for a while and didn't get good pedal springback and was half way engaged a lot. The spring is a bitch to remove..... I have the SPEC stage II clutch - similar to the CFII offering.... It with the hydraulic clutch setup makes it very easy to activate the clutch. Like driving a manual Toyota - one toe... Quote Share this post Link to post Share on other sites
9350 10 Report post Posted March 23, 2011 stangs-R-me, A couple years ago, I restored my 69. When I did, I decided to take out my original 351w and store it in my shed. I replaced it with a Ford Racing 392 stroker. I had the Centerforce DF and had no problems at all. It's still attached to the engine, collecting dust, so if you want to try a used one with less than 1500 miles on it, you can buy it for the cost of shipping. The Summit part # at the time was CTF-DF700000. Time to get rid of the old parts.... let me know if you're interested. Tom Quote Share this post Link to post Share on other sites
stangs-R-me 121 Report post Posted July 22, 2011 Well, it has been a long 4 months and I finally got Tom's slightly used DF clutch & my rebuilt trans back in. I'm re-using all the stock clutch linkage ... removed the pedal assist spring as required with the Centerforce clutch and rebuilt the clutch support using one of Mustang Steve's ball bearing kits. Replaced all the plastic bushings & felt washers, everything else was good. Now with this diaphram clutch, I had to shorten the pushrod adjustment quite a bit as it has the release lever / fork much further forward ... is this normal ?? Also, should I still be adjusting the free-play between the release rod lock nut & block to the 0.194" specification or should I be doing something different since this is a diaphram type clutch ?? Thanks, Doug Quote Share this post Link to post Share on other sites
stangs-R-me 121 Report post Posted July 24, 2011 Update ... after writing above post I then went back out in the garage & pushed in the clutch pedal and heard a pop and figured the TOB was not seated properly before. So I had to re-adjust the stop nuts back out (probably close to where they were before) and it all seems normal with the 0.194" of free-play. Wow is it ever lighter than my old (Ford re-man) 3-finger clutch that came out !! And the drivabilty is no different than stock with absolutely no chatter. Thanks again Tom for offering me this clutch !! Doug Quote Share this post Link to post Share on other sites
sportsroof69 13 Report post Posted July 25, 2011 Those clutches are great, and they have great holding power as well. Quote Share this post Link to post Share on other sites
