Good man, best to do it all now, saves pulling the pumpkin back off in 12 months time to replace worn clutch plates.
Those friction plates are totally shot. What thickness have you left? I can't see any grooves in the pic at all. You have set up height in the workshop manual of the pressure plate splines above the flywheel. There is a degree of tolerance but I suspect you are outside that. Getting over 30 out of a ferrari clutch is good going. But is always something I would check know and probably replace whilst in there if over half worn given the small amount of wear parameters on these. If your getting relined I would always do the pressure plates as well, if a refurb make sure the shop is able to add material to rear to make up for any loss when skimming. And that they are able to balance it properly. Also check there is no sideways movement in the flywheel indicating wear in rear pumpkin bearing. That could be affecting your angle of attack too. Another problem I've seen is loose rivets on hub mount. All repairable don't ever buy new flywheel from ferrari!
Discs are 6.6 and 7.1 From the link that 348Jeff provided here: The intermediate plate (#5) should have a thickness of 9,0mm. The driven plates (#6 and 7) when new, without a load on them, should be 7,25mm thick. The wear limit of 0,8mm means that if the plate measures less than 6,45mm thick without load, it is beyond the limit and should be replaced or relined to the original thickness. If you compress th edriven plate under a load of 535daN, a new plate should have the thickness of 6,90mm, and a used plate should have thickness no less than 6,10mm (6,90mm - 0,80mm) When the manual says "replace the entire assembly" it's referring to the clutch kit or stack assembly, correct? Why the whole assembly and not just the discs. Granted, the whole thing if extensive damage e.g. rivits groovin' the pressure plates. . Image Unavailable, Please Login
Speaking of stack height, I've seen lots of how-to's here for the Brotherhood but haven't seen a visual/procedural description on doing this measurement.
I believe what thy are saying is that if the setup height is out of range when assembled with new disks then replace the hard parts. Or it's nothing more then one of the many written excuses Ferrari propogandizes to help the dealerships seperate you from your money.
Yes, imagine shelling out over a grand for two new OEM discs only to have the stack come up short. Then spend another $2k for the whole kit and kaboodle, which includes two new discs. I can also imagine that if the plates and flywheel have been resurfaced several times (or aggressively due to heavy scoring) then buying the whole kit is the way to go. Speaking of... why are the discs half the price at Superformance? AP Racing Clutch Disc - 136804 & 136805 http://www.superformance.co.uk/348/clutch.html $285 Each or $570 for both http://www.ricambiamerica.com/product_info.php?products_id=198048 $580 Each http://www.ricambiamerica.com/product_info.php?products_id=198049 $580 Each
I do not think your stock setup height could be out of range enough to prevent reinstallation of even below spec discs. I have used these guys to resurface clutch discs. You MUST be very specifc with these people that any clutch that is rebuild outside of specs will be returned. Make sure you let them know the uncompressed and most important compressed thickness. One reason I like organic clutch discs is that they wear much faster than the metal. So there is a 90% chance you leave the PP and FW alone and get organic plates made to spec and it will work just perfect for a street car. In fact, I lightened my FW pack and removed marcel springs in discs and remade discs for under $30 bucks a plate back when I raced my 348 and it worked perfect under race conditions. Ferrari wants you to buy the whole assembly. If I was selling you clutches for a living that's what I would recommend too. My kid needs shoes. Friction Materials 1425 Santa Fe Ave, Long Beach, CA 90813 (562) 436-4224 https://www.fortwayneclutch.com/
The thicknesses i have are Intermediate plate thickness 9.00 Friction plate Thickness at rest 7.25 Thickness under load 6.90 Wear limit 0.8 and Set up height 47-51mm above flywheel surface so the plates are not as bad as first thought but could do with a reline. The thing to check with the metal is for any dishing, whist fbb is right organic causes less damage in terms of removing material it can cause lots of heat that does its own damage. so check they are flat at least, all of the contact surfaces. as to the contact height we always do that on a table with hydraulic spindle to clamp it down, so far easier than when on car. if you have a hyd press you could make something up that clamped it down and enabled you to measure this. or drill and tap a few holes into something flat to bolt it down to, then measure to that flat surface below. But i am also keen for you to check the rear bearing is ok, which is simple, just rock the flywheel from side to side and see if any movement. good luck.
Thanks, my thoughts as well (organic) since it's only a street car. So far all of the components looks very good and the faces on the FW and plates are very smooth. Will check for flatness..
Great info, thanks. With this and what FBB mentioned I plan to photo-document the stack Set Up Height (SUH) measuring procedures. And great tip on the FW bearing, which is smooth as silk and rock steady too.
While waiting for new discs to arrive I was finally able to get the bell housing on as a test fit. Bell housing and flywheel only: . Image Unavailable, Please Login
I'm convinced that the prop shaft needs to go in first and, without a perfect alignment (due to handling the weight of the complete package), it's nearly impossible. Or lots of luck needed. With the clutch pack removed the pumpkin is easier to maneuver; one hand lift and guide from underneath with the other rotating the FW. I'm still guessing that the SUH was too low/short with the worn discs. As a result, the clutch discs did not engage first thereby acting as a guide for the prop shaft afterwards. I'll find out for sure when the new discs arrive...
According to my measurements, both splines start engaging at exactly the same time/position. The distance between the starts of the splines is 51 mm on the shafts and exactly the same measured on my twin clutch & flywheel assembly that I have not disassembled yet. I don't know the wear of my clutches but it should not be much after 12,000 miles. If the wear is at the limit (0.8 mm per clutch) the prop shaft splines would engage 0.8 mm earlier than the clutch splines, provided the plates wear is equal at both sides (0.4 mm per side). 0.8 is not much and should not make a difference. I just completed "fabrication" of my guide-studs. My car is on the ground (rear wheels up) so, in addition to the guide-studs, I will have a scissor jack under the pumpkin to fine-position it and not let it hang on the guides. Hopefully, it will go in fairly easily. Image Unavailable, Please Login
M, that was my initial experience as well, both at the same time. Your guides look right. I tried some long bolts but there was too much free play in the bell housing bolt holes.
Small correction: if both clutches are 0.8 mm worn, the prop shaft would engage 1.2 mm earlier than the clutch splines (0.8 mm wear of the inner clutch plate + half of the wear of the outer clutch plate. The slack in the housing holes over the stud-guides you mentioned is the exact reason why I intend to support the assembly with a jack which will take the weight and I will also be able to center it around the stud-guides. Then I will have the feel of what is happening inside.
We have done this more effectively with 2 people - me under the car providing the muscle to support the pumpkin and Ernie above to guide the splines/plates. Ernie would engage the first disk then rotate the pack a slight amount to get the second to grab. Seemed to work best after a break, beer and topping off the F-ing curse jar.
Well, I've been able to get back to this project today... and it went back together, easily. After I reassembled the clutch pack and as suggested by Bill at Speed Works; Loosen the 6 bolts and align the discs Retighten the bolts just a bit, then test fit the pumpkin by lifting from underneath and wiggling a bit. It slid right on within seconds Gently remove and lower the pumpkin, check the alignment, tighten the 6 bolts a bit more and then refit. It slid right on again. Remove again and torque the bolts. Reinstall... it slid right on with no issues at all. The whole thing was so easy it's comical. Everyone has their first time. Thanks all for your suggestions and comments. . Image Unavailable, Please Login
gee. what are you using for an alignment tool? I used to do dual discs by eye! then I acquired a broken clutch shaft and the clutch pack goes on 100% of the time no problem. Sounds to me your speedworks method is making up for a cruddy tool. glad you are back together.
Bill said that I needed to use a proper alignment tool, my reply was that mine is from Hill. Prior to the steps above, the pumpkin just would not go back on, and I checked the disc alignment previously as well. Sounds incredulous I know, but that's how it turned out for me.