Yeah,i wouldnt have bought one here 10 years ago,but you only live once,so i thought why not??I was acutally goin to hold up until i moved down there, I want to move to the Gold Coast in maybe another year or so.I can go now,fly in/out work for way more money than im on now,but ive been here all my life and thought ill stay another year at least............maybe!! hehe. I bought my car from Emilito Classic Cars,Glyn Pearce,on the Gold Coast.
I was under the impression that the center bolt (the small one) controlled the fore/aft location of the flywheel assembly, and thus the clutch assembly which is directly bolted onto the flywheel, inside the clutch housing. Since I never knew how to correctly make the adjustment, I simply recommended that anyone removing the flywheel make some index marks to show the original position of the center bolt, before removing the ring nut, and set it in the same positon when reassembling. I would like very much to be educated on how to set this up properly. There must be a procedure for it.
FYI DIY'ers. The big nut holds the flywheel positively at all times, and should be loctitied. The aluminium cap (with the horse on) on the back of the bell housing locates the main flywheel bearing into the bell housing to control rearward float. The grub screw in the middle of the big nut, gently preloads the input shaft, to hold it against the little snap ring on the shaft, to stop it chattering and moving... which is why the triple seals often leak.
Ferrarifixer, thank you. If I interpret your message properly the grub screw is independent from the larger nut. The larger nut should be tightened and loctited in place. The grub screw is then screwed in until it contacts the shaft end to prevent any fore and aft movement of the shaft within the gearbox. If I recall correctly when I rebuilt my gearbox, there is a small pad between the grub screw end and the shaft end. Knowing my memory I could be completely wrong there as well! I will try this weekend. Again, thank you. John in the very snowy US northeast!
can someone post from the parts book TAV 24 of the second parts book perhaps No Doubt can do it. Then I will explain why Ferrari fixer is wrong. I can post a pic but don't have a scanner to scan the page.
No Doubt would love to, but won't be back from vacation until next week (in the meantime, he's stuck at 40k dialup with no electronic access to WSM's).
One pic from my Parts CD; one attached page from my scans. Image Unavailable, Please Login Image Unavailable, Please Login
Screaming baby in one arm + glass of wine in one hand = screwy post (Thanks Paul!! Just what new parents need for Xmas!!!)
See Miltonians post of TAV 24: Thanks for posting it. Let me qualify my statements in case anyone does not know...I am not a professional mechanic but an obsessed DIYER who races his 348 been through 3 Ferraris and fixed numerous others and thats all the experience I have. My contention is that the input shaft is not preloaded and especially not preloaded by the rear hex #57. Preload is something you do with shims like preloading a ring and pinion in a differential. There are no shims nor crush washers in these drawings. Input shaft # 12 goes through # 2 clutch shaft and is splined and stops against a land of metal in #47 flywheel assembly. #48 buts into the backside of this land and can not exert pressure on the shaft #12 except to barely touch it. It cannot tension it and if it tensioned it then you would have metal on metal with no oil or grease spinning at 8000rpm. There is snap ring 30 which goes on shaft 12. The input shaft is trapped between the snout of shaft 2 by the snap ring 30 and the face of #48. It is a passive retention but precise design where the input shaft is basically free floating on its bearings. Any preload design would not be done with metal on metal i.e.the input shaft end on the bushing 48 or on a non-360 degree snap ring in a round land. The internal of the snout of #2 is the same diameter of the shaft 12 with its sealing rings 13 for a distance that is very long. The shaft being trapped between the said features above cannot allow the shaft to move enough to make the seals leak. Those seals leak because of a crappy design not because the shaft 12 can be improperly positioned. #48 is free floating and is not threaded but just a stepped bushing type unit. I find the easiest way to assemble clutches is to place the flywheel assembly on the clutch shaft indexed with the input shaft. Then place the bell house #44 with its installed bearing onto the tail snout of the flywheel assembly. Then torque nut 56. This may or may not be installed flush. Final relative position of the assembly will be finalized when cap 58 squeezes the free floating bearing #55 between the cap 58 and the tail end of the bellhouse. The remove the cap and you will find the bearing flush with the tail end of the belhouse. You can then use a bit of 242 locktite and place #57 hex screw until it meets resistance onto #48. You cannot over torque or force this because #48 cannot be pushed past the but end of the land built into the flywheel assembly. If you look at the drawing I took from 348 paul you can see the line 1 and 2. This is where the input shaft is trapped regardless of hex screw 57. Also you can see the land in the flywheel assembly at the point of line 2 and thats where the shaft can go no further posterior and the cap and go no further anterior so the hexscrew has no function other than to hold the cap 48 in position. You can also see to the left of line 1 how long the snout of the clutch shaft is and why the input shaft cant move to fore and aft to aid in the triple seals leakage. Also you can see at the point of line 1 the small snap ring #30. No designer would preload that. It is not even concentric. Image Unavailable, Please Login
Ok, thanks for diagrams, it helps explain much easier..... So, the grub screw preloads the little steel cap, which in turn controls input shaft position if you want to be pedantic. Bottom line, if grub screw or big nut is not done up correctly, then either the flywheel is loose (major drama) and/or the input shaft can float around... encouraging the triple seals to leak.... NEITHER big nut nor grub screw have anything to do with clutch adjustment... which is why I pulled No Doubt up... and he was simply quoting FBB from another post.... So there we have it. 348 clutches are not adjustable, and installation must be performed correctly, without variation or interpretation.
I've been studying this. I have some questions, but it's 3:00AM. This color diagram might help to understand the guts of it. Image Unavailable, Please Login Image Unavailable, Please Login
Interesting reading. I was suprised to see that the exploded views in my '90 348TB/TS parts manual (TAV21 and 21/A) don't even show the snap ring identified as item 30 in the exploded parts manual extracts and discussed in this thread. Even though my manual shows exploded views for single and dual disc clutch the snap ring isn't shown in either! Was this simply an accidental early 348 manual illustrative omission or was the snap ring a later addition to the clutch assembly?
1) Airgap is not preload. 2) End cap does not protrude beyond flywheel assembly land and cant effect input shaft, 3) the input shaft does float between the snap ring and flywheel assembly land, 4) endcap and hexscrew can only effect position of flywheel assemly as that is the only thing they are connected to. That is what the pictures show and I just confirmed that the endcap does not protrude beyond the flywheel assembly land from Ernie's gearbox apart in my garage right now. It seems pretty clear to me and has worked in practice and I have done many of these, modified one outside Ferrari specs. , and race on this premise for 5 years with no ill effects. I would assume if I did it wrong after 5 years on the race track my clutch would be toast. Its not its still going no and its 6-8 lbs lighter than stock with a stock motor. Image Unavailable, Please Login
Fatbillybob, preload is perhaps not the correct term for the function of this screw/ cap assembly. From the schematics and Ferrarifixers posts it appears the assembly does limit input shaft float. Am I correct in this assumption? Adjust grub screw to limit the input shafts ability to move fore and aft? Thanks.
Ok - How about this one then???? Taken from the 348 WSM and bound to open a can of worms!! I have my own theory but I'm keeping quiet!! (for the moment!) Paul Image Unavailable, Please Login
