I've been searching and can't find the answer online or in the WSM. Just replaced tensioner bearings with Hills bearings during my engine service. What should the torque of the single bolt be set at?
If you check the workshop manual (you can down load for free from "my348.com") on page B88 there are some torque readings. One is for "chain tightener fastening to crank case".... I'm guessing that's the tensioner bolts. They list 58 nM which is 42 ft lbs.
No, that's for the timing chain inside the engine, behind the front crank cover. I looked for the torques spec for the cam belt idler and tensioner bolts and cam up with nothing. My shop manual has jack squat for that spec. When I did the belt on my 348 I did it by feel, so I have no definitive answer for you. Sorry.
TADDOW! How ya like me now. "Securing timing belt stretcher. Thread = 12x1.25, Torque Kgm(FT.Lbs) 5.6(40.5)" Found it in on page #41 in the M section of the 328 manual http://ferrari.stevejenkins.com/books/328_tech.pdf It also has LOADS of other torque specs which should translate to other models. The thanks goes to Verell for posting the link in Dec of '03. http://ferrarichat.com/forum/showthread.php?t=2770 "Seek and ye shall find".
10 mm nut, F355, 49Nm 12 mm nut, 328, 56Nm unknown for the 348 but pick the right size fastener and go with that.
Yes, that is how nuts and bolts are specified. Size of the shafts not of the heads. oh, I can take this in so many directions but let's keep it PG13.
Ernie, Is it safe to assume that the bolts going into the cams for the timing belt cogs would be the same?
I know of no reason for the 348 cam gear bolt torque to be different from the 3x8s. That torque is: You really should have a copy of this document.
Updated link to the manual that has the torque specs referred to in the post. http://www.cannell.co.uk/Ferrari_Workshop_Manuals/328_technical%20Data.pdf
Any more thoughts on this? I see posts referring to cam gears, but the question was about the tensioner. The tensioner on the 308/328 calls out for 58 nm on my documentation. The difference is a steel stud with a nut (nothing in aluminum) not a bolt going into aluminum. the reason I’m asking is when I was going for the 58 nm (stupid me reading Ferrari tq specs, but there’s no bolt that large on the chain tensioner inside the motor) the sliding tensioner went fine but the fixed tensioner felt like it was stripping. I read this thread and put a digital Matco on there and it was staying at 43 nm then went to 48… it might of been the bearing seating in the housing. I loosened and it clicked at 48 nm no problem… I appreciate all the comments here, and like to think 48 nm is good enough if others have ran there… but I’m not closed up yet and if the block the tensioner threads into strips I can helicoil it.. don’t want to if I don’t need to. If there’s already a helicoil it should be fine… but I don’t recall. Appreciate any follow up comments on where people tq the tensioners. cheers
Is do 48. Most shops probably do good and right by hand. Sent from my SM-G990U using FerrariChat.com mobile app
For the life of me I cannot figure out why anyone would work on one of these without the factory workshop manual and instead rely on information from self appointed experts on the internet. If this thread alone does not have enough disinformation to convince someone of that I don't know what would.
I have the manual and It’s a poor translation that makes things unclear…. So maybe u can just post if it should be 58 nm and if it strips so be it.. I for one would appreciate that and you’d be clearing up the misinformation… trying not to make myself work…
No one is self appointed. And he does have the manual. He asked so someone answered. They can take it or leave it of course. Sent from my SM-G990U using FerrariChat.com mobile app
Yep appreciate it and I thought the dude who originally posted the lower torque values has a lot of successful hands on experience… Definitely not looking to raise anyones blood pressure on a Sunday morning .
Oh man I’m so guilty of contributing to misinformation.. I thought the reference to the 308 having same size bolt/stud was to the cam tensioner… and my brain was not firing clearly with the discussion about cam pullies mixed in.. it’s m12 on the 308 … 58 nm… but the fact still remains to me that the 348 manual clearly states 58 nm for m10 chain tightener, which I’m just going to ignore I guess. Apologize for adding wrong info.
And I just unscrewed the 348 tensioner bolt to make sure it’s m10… making sure Ferrari didn’t pull something with a 12mm shank 17mm head. Sorry about my misinformation ramblings about comparisons to 308 set up..was comparing torque values etc and thought from memory it was same size. I’ll think even more before I post . Unfortunately having the manual is really not helpful in this situation, but I could be completely dense and missing an entire section..?
Personally I use the standard toque values (shown below) for a fastener based on the bolt grade as a starting point when the manual is not clear, does not specify, of if I want to check translation. Some one will be along to call me an idiot shortly I'm sure. That spec 58nm seems translates to roughly 42 ft lb. Its but into aluminum, so there that. 48nm you mentioned is about 36ft lb so not too far off. Many of these engines have had bolts over tightened, I always worry the correct torque will strip the aluminum threads, for some bolts at least. A thread chaser is probably a good idea but I have seen some holes with the bolts in the hole 80% in, the bolts wobble. Image Unavailable, Please Login Image Unavailable, Please Login
As can be seen its not a matter of confusing information, Ferrari did not provide a torque spec for it. The internet has a great many resources for determining correct torque. You need to be sure of thread diameter and pitch as well as material it is threaded into .Iron, aluminum of a helicoil. On many fasteners screwed int aluminum Ferrari used helicoils to increase the strength. Also the manuals are written for experienced mechanics and in many ways Ferrari was not as concerned about exact torque. In many cases read in the Italian version a torque is given as "At least X nm". As important as they are do not expect those manuals to tell you everything or be correct 100% of the time.
