Image Unavailable, Please Login Found in Transmission,,, Cambiocorsa Pan. Ferrari Crown Ring Bolt/Locating Pin. Ferrari P/N 106777 $ 98.00 for one.......!!!!!!!!!!!! Note the machined stress riser under the hex cap. I wouldn't give you $0.02 for anymore of these,,,,,,, for your gonna break them all. Pulling Mondial-8 differential now. (whew)
The holes thru the differential have plenty of "chamfer," on the Sx side. Why the 90 deg stress riser under the bolt hex head???????????????? Image Unavailable, Please Login
Aaron, AAAA ha ha,,, that is the trick. To Have,,,, The bolt finally jam inbetween the Crown Ring Pilot, and the Rear end cover..... at 2 mph,,,,,,,,, in my gravel driveway. (whew) so, Luck is my middle name. I must be a Tabby Cat ( Like Tippy, my last and best cat.) ,,, for, I'm definitely into my 7th life.. ha ha
Hey All,,,,, the search function is your friend. Verrell,,,,has been down this road, 13 years ago. I'm going to use (4) Ferrari Factory 106777 Crown ring bolts. With New,,, Ferrari Nuts 104011,,, properly torqued. Alternated with, (4) 10 x 1.25 x 70 Cap Screws, Gr 10.8,,,, with the M10 nuts used on the 308 CV joints. This is my best guess for an adequate repair. All Ferrari Engineers,,, and resident expert on Unobtainium parts,,, Mr. Birdman,,, aka Verrell, Please advise, Edwardo
https://www.ferrarichat.com/forum/threads/where-is-a-10mm-bolt-used-in-in-the-308-transaxle.43305/#post-134630046 Above is the link from 2005.
Thus, Birdman was correct in his quote," So, what we do is Just shop for thickest grade 12, 10mm bolt we can find. Correct he is. The problem is Not The Bolt.... The hole is too Big...! The Crown Ring Bolts break,,,, because, the Ferrari geniuses designed a 0.020" clearance,,, in an application that requires an, " ASA Class 4 fit, 0.0025" max. clearance. My FAA Certified mechanic says, 0.0010" clearance is preferred. Note, the next class, a class 5 'interference fit," will require 0.000" total clearance.... ARP has Grade 12 Bolts. Shoulder Diameter is 0.392" a Full 0.001" thicker,,, then the Ferrari Factory Crown Ring Bolts, p/n 106777,,, and, The Heads Won't pop off,, at 75 MPH,,,, sideways in the fast lane. Image Unavailable, Please Login
Correction........for the crown wheel bolts. correct ARP part number is 663-1009 Image Unavailable, Please Login
And, Pilot Housing all clean. Crown Gear installed. Housing installed. & Differential bearing pre-load performed. Image Unavailable, Please Login Image Unavailable, Please Login
Mr. Verell, Thanks for chiming in. 15 years ago,,, we used WOODEN DOWELS.. I mean, New Improved Ferrari Bolts. Just, same old design flaw..... with new bolts. Sheeeeeese,, laweese!!!!! That square peg just fits in that round hole.. But, it is still Wrong. Ha That ARP bolts are 0.001” thicker
Verell, Hello, Hope your out enjoying this great driving weather. And, Yes, you are correct... I was considering cutting off the extra 3/16” of protruding threads,,, down to a proper 1/16”,, But, the ARP bolts are installed in the opposite direction as the original Ferrari bolts. Thus,,, the ARP bolt head is against the crown wheel and the clearance for the protruding threads is greater. Whew
Noisey front cover,,,, found a bad Cam drive bearing. 1) Make a SYKES tool for front cover bearing. Lucky,, My car has Outside, Cam Belt Drive bearings. or, Pull Front Cover in the car,, , , see 308GTSi procedure. , , Image Unavailable, Please Login yikes.,......!!!!! Image Unavailable, Please Login
All,,,, beeen a while. hope your all well.. Front cover bearing... done Now,,, see rear head,,, pulled due to burned valves in # four cylinder.. Due to bad brake booster. ( Brake Booster issue, rebuild it for $ 200.00,, sent to Steve at Power Brake Booster Exchange... they do Ferrari...) harumph....!!! Thought that a hobby was supposed to make your blood pressure go down....???? ha ha Now, Everything should be fixed... (whew) Thank You Climate Change.... ha ha endless summer here in California. Drive those classics... (smile) Eduardo Image Unavailable, Please Login Image Unavailable, Please Login
After my brake booster valve failed. (Thus,, burning the intake and exhaust valves in # 4 cylinder. ) Some internet threads debate as to the usefulness of moving the Brake Booster vacuum port,, from its factory position on cylinder #4 intake runner,,, up, into the intake plenum. 1) In the event of another Brake Booster failure,,,, The factory position allows only #4 cylinder to go lean... Somplifying repairs and isolating damages to the rear bank and head,,, which can be removed easily with motor in car. 2) You can actually remove # 4 Piston and Liner,, with the motor in the car. ( After the difficult,,, oil pick up tube removal..) 3) When you lift the throttle and stab the brakes,,,,, The motor gets a slug of air from the booster. All cylinders are running lean at this point. Thus,, it doesn’t matter if #4 is running lean,,, it’s not under load.
So,,, I am going to ignore the above factory logic. in photo,,, on left,, See 1/4 “ hex plug installed in cyl. #4 intake runner. The thread is actually a 7 mm ,,, but, a 1/4 NPT fits nice,,, with lots of teflon tape. Image Unavailable, Please Login
This is how the longer ,,, brake booster vacuum tap will look ,,,, when installed in the plenum. When I stab the brake peddle,,, It will deposit air into the intake stream for cylinders #3 and # 6. I will continue to monitor the Air/Fuel mix with an O2 senser in the foreward bank. We will see how lean it goes when I stab the brakes. Ok,, so now I need feedback. from you guys. Good idea or not???? ( whew) Image Unavailable, Please Login
see soldered copper tube in New 3/8 NPT hose barb. I added a 1/4 inch hole in the side,,, to promote turbulent flow. Image Unavailable, Please Login
Note: This intake system for the 308 GTSi series of motors has the characteristic of poor flow into the rear bank of cylinders. Numbers 1 - 4. Thus,, the rear bank ,,, always runs leaner then the front bank. This is not good for the Cylinder #4,,, since it is already required to gulp the extra air from the brake booster. of Last Note: The hose barb is cut as short as possible to allow the 1/2” vacuum hose to clear the Mondial engine cover frame rail.
Edwardo, When you put the lower belt drive pullie back on, how do you know it is on the snout far enough or too far?