DDK - Die Deutschen Klassiker

This is what my washers are like for the door hinge bolts. Same as on the torsion plate eccentrics but smaller.



Anyone know where you can get them? I need 12 and only have 11 as one of my door bolts was missing, together with the washer. Have replaced the bolt - it was one of the infamous cheese heaed botlts with the 12 point star rather than the allen head, but need the washer

Try Matt at Type911 first but then I would go to the OPC

Ian

Search ebay/google for 'schnorr washers' ...

and the prize for knowing what they were goes to...!!

Thanks

Dougie,

I assume you are not re-using your old ones as they are a one time only washer.

Got mine from these guy's

https://www.ebay.co.uk/itm/SCHNORR-WASH ... 2a6ae14480

i just bought some from those guys on ebay. Why are they only one time use?

The serrated edge bites onto the bolt head once torqued up. The washer will flatten and have no serration after removal.
Better safe than sorry.

stretch wrote:
Better safe than sorry.

Especially on CV joint bolts...

And i will be buying new CV bolts too Richard..!

There are some subtleties involved when using Schnorr washers.

The 'S' Type washers commonly sold on EBay have a relatively low preload capacity and are generally used on bolts up to and including Grade 8.8.

If you use them with a Grade 10.9 or in the case of a CV bolt I would suggest using a 'VS' rated washer as this is thicker and has a substantially greater preload capacity. Even using VS washers Schnorr rate them for use with bolts up to grade 10.9.

There is no real reason why Schnorr Washers are 'use once items' as if they deform permanently then they will cause a loss of preload which will cause bolts loosening which has serious consequences.

I would say at the price they may as well be replaced but it isn't essential.

For CV Joint Bolts I would really suggest using the VS component as it will be more secure and be the most appropriate washer.

CV Bolts themselves are clearly important and there is even more confusion in this area.

I would only use Grade 12.9 Bolts from a supplier such as Unbrako or Holo-Krome as they are manufactured to very high standards and are reliable.

The aftermarket is now awash with cheap fasteners that may not provide the same degree of integrity.

There is much discussion in the USA about not using any lubrication on CV bolts as it is claimed that any grease will cause the bolt to loosen in service.

In reality this isn't good advice as the stiction, particularly for new bolts, that is present when the bolt is dry will increase the scatter in the preload and there is a significant risk that some of the bolts will not be sufficiently tight. For a new bolt that is unlubricated around 80% of the applied torque is used in overcoming friction and only 20% causes the thread extension that generates preload.

The best way to tighten a CV Bolt is to use a torque + angle method as this will reduce preload scatter and provide a more reliable result.

If you are going to simply torque the bolt then when using using new bolts I would also suggest tightening them 2-3 times before final torque application to burnish the new thread as this will also help to reduce the risk of under-tightening.