Hey guys, I've not been on here in a while but I'm having an issue with the clutch on my 32 3 window. I have an 8BA, Fidanza aluminum flywheel, pressure plate (diaphragm type) and disc from Speedway (listed as FOR flathead Ford), FTE hydraulic throw out bearing that came with the Keisler (now Silver Sport) TKO. All new pieces but the clutch will barely move the car. I've had this engine/transmission out 10 times, and I can not figure out what the issue is. I've talked to local car guys, local hot rod shop owners, social media car guys, even Silver Sport and I'm no closer to getting this to work. I've measured the clearance on the T/O bearing 5 or more times, blead the master and throw out multiple times, replaced the pressure plate AND the disc. The disc is tight when I tighten up the p/p bolts, the fingers move in a good 1/2 inch or more. I can see the throw out bearing moving in and out when it's all together. The throw out bearing, I even removed completely and is still slips, so it's not that. I've checked for interference with the input shaft, it's not bottoming out on anything. I'm right at the finish line but the car will barely move. I can push it fine so it's not brakes holding (if it was brakes, it should kill the engine). I'm totally baffled. I've done clutches before and never had this kind of problem. Though they were direct replacement deals in my 55 Chevy and 69 Camaro. Do I need to switch to a stock type Long style pressure plate? Can I use the hydraulic throw out bearing with that? I thought I read somewhere NOT to. I'm so confused and frustrated...and REALLY tired of pulling out and putting the engine back in. (it's still easier than trying to pull the trans by itself) But that's the only way to test it. And buying multiple clutch kits at $$$ each (that may not fix it) I just can't afford.
Explain that process to me. Is this an internal slave or external unit? What is your clutch pedal ratio? Pics?
It sounds like what you're trying to say or at least describing to me is that the pressure plate isn't making enough Clamp Force between the Flywheel and disc. Would that be a correct but difference description?
I guess I was a bit extra frustrated after failing for the 10th time. I’m using a hydraulic throw out bearing. (“Slave” to keep from having to type out hydraulic throw out bearing…again lol) And a matched (according to all of my paperwork that came with the transmission kit that included the hydraulic throw out bearing ) Wilwood master cylinder. ie: Bore/stroke I don’t remember the pedal ratio numbers. It was what was recommended by various sources and I did that several years ago.
I was referring to the bleeding process. I use a Mcleod TO bearing on the input shaft behind my 8BA. The bleeding process is not like wheel cylinders but I guess you have that figured out after 10 R&Rs. The first time I installed mine I miscalculated the distance and had to order a spacer (1.5"??) to get that TO bearing to engage properly. I also had to cut .250" off the input shaft and turn it down a bit to fit my pilot busing. I didn't have to do it 10 times but it did take 3. I feel your pain.
Sorry, I misunderstood. This one has a bleeder valve on the feed line and I used one of those “one-man bleeders” and just pumped the pedal by hand and watched for the bubbles to quit. I’d hold the pedal down for a minute or so every few pumps then continue. The cup on the master is really small and I’d have to refill every 3 pumps.
This sounds like the clutch disc is not being clamped on both sides. Either the disc is backward and the hub is keeping the disc clear of the flywheel surface, or the clutch hub is hitting the pilot bearing keeping it from being clamped between the flywheel and the pressure plate. More than likely the latter as the former usually causes the clutch to not release cleanly. And if the disc is stenciled flywheel side on one side, it wouldn't be the first one I have seen stenciled wrong
Okay, some real basics here. I have no idea what kind of Mechanic you are so don't take anything personal. Mix-n-Match aftermarket Kit parts is a Circus act most often. Just because parts bolt together doesn't mean the package will work as a system. I'm not going to visit anything related to your release system, just the Clutch package and maybe something will show up. You must know by now the aftermarket suppliers don't give a Damn if what they sell you actually works after they hit your Visa card. Sounds like everything inside the bellhousing is aftermarket and no 2 items are listed for the same package from any one builder. I believe your issue may be compatibility between Flywheel, Disc and Pressure plate. Probably disc and Flywheel. You stated this and I quote// "The disc is tight when I tighten up the p/p bolts, the fingers move in a good 1/2 inch or more. I can see the throw out bearing moving in and out when it's all together.". Just because a Disc Hub fit's your input shaft doesn't mean it is correct for the other 2 items it comes in contact with. Did you mount the Disc to the alignment shaft and place it in the Pilot bushing and make sure the Disc went full against the Flywheel face and spin without letting the splined hub making contact with anything? I have seen that happen with Race version Flywheels that are light and also much thinner than a stock one. You can bolt it together making a Cone of the Disc and thus only making contact on the outer edge as mentioned above and not enough contact surface to Not Slip. The Pressure Plate can also be a misfit with more recess from Flywheel face of Bolt flange to disc surface to accept a thicker than you have Clutch disc. Either one of these issues and specially both together will not make enough Clamp Force to not let the disc slip yet making the disc seem tight by hand or by eye. If this problem came inside my Shop I would be headed straight to the 3-part package to make sure they are working as a unit. The giveaway here for me is this statement you made, and I quote, " The throw out bearing, I even removed completely and is still slips, so it's not that". I'm pretty confident you have an issue getting clamp force on the Disc.
Engine off, trans in gear. Can you push the car? What rear is in the car? Are you sure it’s the clutch and not some stripped splines somewhere, axle, pinion, output shaft…….?
Wouldn't that be Krazzy, 28 Spline 9" axles in a 31 spline set of spider gears? Nobody would make that mistake, right?
Disc will only go in one way for the pressure plate to bolt up. Bolts would be too short because the spring hub hits the center of the flywheel. But thanks, I HAVE done stupid things before, I ain't gonna lie. LOL
This has been in the back of my mind all along too. I guess I just needed to hear someone else say it. I'm now 66 years old and have been working on cars since I was a kid following my Dad around getting in his way. Am I an expert in all things cars? No and I would be skeptical of most anyone who said they were, unless I knew them personally. I'm a, now retired, machinist of 45 years and know a thing or two about measuring, fitment, tolerances, etc. I've built and worked on a number of cars over the years. From modern to antique and hot rods. I've never seen this problem. The flywheel matches my stock steel wheel almost exactly. Diameter, thickness and flat all the way across except for the recess for the flywheel bolts and the steel insert for the clutch surface. To put the disc in backwards is impossible with this because the spring hub will hit the flywheel and the p/p bolts wouldn't even reach the threads. The stock wheel I mention has some stripped out threads, some chipped teeth and needs resurfaced as well. I had thought about bolting it up just to see if anything changed but I'd have to redrill and tap new holes for the diaphragm style hat, which I have done before, I just don't want to. (I have my own Bridgeport with a rotary table) I've done all the things you've mentioned except forked over another 500+ (pushing a grand, depending) bucks for another all new set up. ("It's just money" Yeah, let's see you say that on retirement income) As a side note: the first set up WAS all bought together (from Keisler, who, by the way "was no more" by the time I got to this point in my build) and it didn't work. Wait, nope. The flywheel was bought separately, dammit. Anyway...Now... Most all of the kits for flatheads show me a Long style pressure plate. Main answer I need at this point: Can I use (reliably) this hydraulic T/O bearing with that p/p? This bearing is the FTE brand. It is the spring-loaded type with the green rubber "boot" covering the spring. (google it for pics) It has the built-in sleeve that the bearing rides on and is bolted directly to the (special) front bearing retainer on the transmission. This transmission doesn't have a sleeve made onto the front bearing retainer to use a conventional or McCleod style (which I do have) throw out bearing. So, you see it could be more than just getting another clutch kit. If I gotta, I gotta, but if I do and it STILL doesn't work...whooooo boy, the air is gonna turn PURPLE! LOL Thanks to all for the input. It HAS helped.
Okay, I'll agree you seem to have a good handle on all the Clutch related package. I'll ask one more Clutch related question. With the P.P. upside down on the work bench (laying on its fingers) and the disc laying on top of it does 50% of the disc stand above the flywheel mount pads? If so, I'd go out on a limb and say it can't be the Clutch. I went back over most of your post and don't see where you say exactly what Gear Box your running or rear axle. It sounds like a 39 style Box and closed drive Ford rear end. If so, are you positive the Axles got there drive keys installed with the Brake Drums? Early Gear box is impossible to have gear slip in first gear unless something is broken. Shaft is splined into the center section. From where I sit the Axle drive keys are the only place left for this issue to be.
Can you see the T/O bearing through the bellhousing? If so is it completely off the pressure plate fingers when released? Or, just barely resting on them. In other words, not holding pressure against the fingers.
Any idea what the gap is when the pressure plate is just sitting against the clutch disc before the bolts are tightened down? If that gap is too small it could mean there's not enough pressure on the clutch disc after tightening the bolts. I'd want to see something around 1/4" before tightening the pressure plate bolts. RAM has a great tutorial they call Clutch University that is a nice resource for troubleshooting clutch issues. Might want to skim through it and see if you can find some info there to help. https://ramclutches.com/clutch-university-chapter-1/
I think I mentioned it in the original post, but it's a Tremec TKO 500 (I think I just said it's a TKO). Rear is a 67 Mustang GT 390 9" that I rebuilt with a Yukon "posi" unit and new Moser axles. The first clutch/pressure plate barely had any friction surface above the mount pads. The second one has maybe not quite half, but much more than the first. Which I thought was my problem solved.
I know building a Posi center section is pretty strait forward but is it possible the issue is there? Maybe the preload springs failing? If it's the gear direct style, no way.
Have you considered scraping the hydraulic setup and tried a cable clutch, they are simple and work like a charm. HRP Check out this how to for using a clutch cable. HRP HERE
Seems like the big question may be, where is the problem. Sounds like you have done everything you can to eliminate the Clutch. I believe I'd get the rear up off the ground and with it running put it in gear to see what's turning. If the Tires spin as expected, I'd start applying the Brakes and see what stops rotating. Is it just a first gear problem or does it follow 2nd and 3rd?
So, I'm hearing: "Get a matched clutch set" Since the aluminum flywheel is the most expensive piece, I'm thinking about calling Fidanza and see if they have either a kit or part numbers from Ram (or whoever) to work with their flywheel. I still haven't read whether the t/o bearing will work with a Long style pressure plate. You've seen the pic of the car. It's not heavy. Back in the day it had a Weber aluminum flywheel and was driven on the street and drag raced. I don't plan to race it, but I'd like to have "fun" with it. Photo from 1955. Avatar from circa 1952
My first rule of thumb is diagnosing the issue before you spend more $$$ and time. If it's the Clamp force alone, by now you should have some witness marks of that on the P.P. and flywheel. To know for sure locking the brakes in gear with motor running and not stalling out should point a finger at the exact problem. Is it possible to be inside the TKO?
Been there too. Wheels turn, brake stops wheels, clutch slips. I put a 2x4 in front of each front wheel. I can let out on the clutch and rev the engine and it won't even go over the 2x. First gear or second. I can feel it try to move, and it WILL move (barely) over a flat, level surface, push the clutch pedal and it relaxes, let out and it tries to move, hits the 2x and stops. Endo camera set under the car shows driveshaft not turning when clutch "engaged". You can see I've tried damn near everything.
I used this one. On the first install I incorrectly measured the distances leaving me with a clutch that wouldn't engage (and actually led to a hydraulic leak when I overextended the bearing and rolled an o ring).... And had to buy this and install it behind the TO bearing moving the TO bearing .700" closer to the clutch assembly. The bearing has quite a bit of adjustment internally but evidently .700" not enough when used with a flathead and T-5. Could it be your bearing is "lacking in metal"? and requires spacing. I know you have taken it apart 10 times already and have likely done the math 9 of those times, and I am not doubting your ability but I made the error when I swore I did the maths correctly. Have you called the manufacturer of your TO bearing to ask them about the issue?
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