Wtf are these bolts?

[Matt Irvine]

Want to change these to normal hex heads, but kind of lost as to what there nominal size is supposed to be..
Mic at 10.84 diameter, 1.0 pitch, which calls for 11mm Metric fine, but that's not a standard by anybody's means.
Came out of a Nissan Navara D22 clutch flywheel.






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[matt_i]

Automakers use M9 and M11s. Their volume and app is specific enough to justify the cost.

That its a 12 point fine says to me its a high confidence application where it getting loose is going to be disaster. Is it a bolt that connects the flywheel to the crankshaft?

If so I'd keep same, I would personally go back with red Loctite.

 

[Matt Irvine]

It's a torx head, yes it is the flywheel to crankshaft bolt

They were going back wil loctite and a torque wrench. But the heads of all 8 bolts are damaged.

 

[matt_i]

I can see the damage now. I think I'd go back with either ARP fasteners (if they have such an app and you can get it), OEM-new spare parts, or try to get them from a junkyard from a damaged motor.

It also deserves the proper inverse torx socket and not a 6 point that's "close". Not implying that you are guilty, but someone along the way was. The basic problem is that with the points of the 'star' damaged you probably won't be able to get full torque without slipping again.

 

[bshusted]

Many of these types of fasteners are torque to yield. The bolt is stretched during the last part of the torque sequence and cannot be reused. The only option is to buy new bolts for the application.

 

[dynahoe]

dealer is your best bet if you want it right. other bolts may work but dealer ones are best

 

[Nuwan]

Use a bolt designed for that application ie: OEM or Aftermarket rather than industrial

If you want to change head style I suggest looking at another manufacturers bolt; Toyota/Mazda or ARP (ie: Subaru which is hex but believe is only M10)

Double check the higher bolt head will clear the clutch assembly as well.

 

[Kevin54]

You cannot go wrong with ARP bolts.

 

[srmofo]

Those look really similar to honda flywheel bolts. If you cant find the Nissan bolts they might be worth looking into. Bonus, Hondas are standard 12 point.

 

[sublimate]

How long?
http://www.summitracing.com/parts/arp-330-2802/overview/

 

[evildky]

Yup nissan flywheel bolts are pretty much all odd size uber fine thread. Problem is the head thickness of standard bolts might not clear the clutch disk. Unless you have an auto in which case have at.

 

[Lippyp]

Yeah the japanese use all sorts of odd bolt sizes, I had to find some 7mm metric fine for something I was doing on my old trooper, really ****** hard to get.

 

[jimbbski]

As far as odd size bolts the Japanese are not the only ones! On my VW they use 11 MM for the head bolts, which are torque to yield but easy to get. They also use 7 MM for the ball joint attachment bolts and on a few places on the transaxle. Also VW says that on my engine the flywheel, crankshaft pulley, con rod, and the aforementioned head bolts are all throw away/one time use only.

 

[Matt Irvine]

Alright, I found some bolts, but what should they be torqued to?
Chart says 88 NM, but all things given, they felt a lot tighter when I undid them