Flywheel bolts-280E engine
 

I am in need of 6 flywheel bolts for a '71 280E engine. I found the part number (1089900419), and they are about $50 EACH!!!!!!

Does anyone know if I could use a standard hex machine bolt with thread locker? The manual flywheel uses such a bolt but does not have the flex plate and washer like the automatic flywheel does. I can't see paying $300 for flywheel bolts. An older thread: http://www.peachparts.com/shopforum/tech-help/14142-flywheel-bolt-problem-m130-engine.html
Thanks in advance, Rich

In the past I have found a pretty excellent choice at Fastenal. If they don't have it in stock they can order them.
I don't know if they have stretch bolts.

A good source is ARP. Purchase by thread diameter/pitch and length. Follow their installation instructions.

The closest I could find is https://arp-bolts.com/kits/arpkit-detail-b.php?RecordID=2965 I think the thread pitch is finer than 1.50, but I will find out. They are not stretch bolts. I am still not sure if these will work or not, NOT being stretch bolts.

I think you could use the non stretch bolts of course you'd need the proper torque spec.

These bolts have a 'seat' under the head that goes into the flexplate and align it and fit very snug. Spend the money and get the OEM bolts, especially considering they're not easy to get to and are in a place you don't want a bolt to fail. At the least, you may end up with vibrations.

Cheaper: https://www.*******.com/products/mercedes-clutch-flywheel-bolt-1089900419

Please PM this link. Thanks, Rich

The implication in this posting is that the un-threaded portion of the fastener functions as a dowel. Threaded fasteners are NOT dowels, they are not locating devices. The threaded portion of the fastener, and the un-threaded portion are the same diameter, and have a clearance in the plates/flywheel of ~.019-.020". A dowel is fitted at .0000 to -.0005"(interference).
The strength of a fastener with a metric designation of 10.9 is ~145,000psi (ultimate), and ~131,000psi (yield).
The ARP SAE8740 fasteners have strength of 180,000psi (minimum ultimate), and 162,000psi (minimum yield).

The vendor in the link is F-C-P

If you’re not in a hurry, you can get them for 26 EUR a pop, plus shipping, here. Possibly you could save an additional 19% since VAT should be excluded on exports.

https://www.ebay-kleinanzeigen.de/s-anzeige/schraube-a-1089900419/684950024-223-8865