Nylock nuts?
 

Hi,
Does anyone know if the M8 nuts for securing the engine oil cooler to the engine, as well as the chain housing are nylock type or the regular non-locking ones?

Mine seems to be a mix of both - 2 are nylock & 2 are regular in each case?

Particularly on the chain housing, am wondering if the heat will actually melt the nylock mechanism?

thanks...

I belive the proper use is nylocks for the outside of the chainboxes with crush washers, steel washers and regular nuts on the inside.

Use the nuts from the Porsche part system that have the high temperature fibre locking insert; the insert is colored brown, black or blue. The common white nylon insert nuts will soften and creep at engine temperatures.

Thanks Jim & Tim...

In my case, I'm really looking to need ~10 of them - I guess dealer is the answer then? And do I simply ask for M8 locking nuts? Any specific part #?

Any import service shop should have plenty on hand to sell you, at significantly less cost than the dealer parts counter.

I've yet to find a non Porsche parts system source for the high temperature fibre metric lock nuts. Many places have the metric white nylon "nylocks" but these are not the same. Jim

Oil cooler is attached with four regular steel hex nuts (900.076.025.02) and B8x15 wave type spring washers (900.028.024.02).

The chain cases are attached to the case halves in the back (front of car) with three 8mm fibre insert locknuts (900.084.004.02 or Pelican J-084-004-02) bearing on 8.4 mm aluminum washers (900.031.014.30) and with two regular steel hex nuts (900.076.025.02) with B8x15 wave type spring washers in the front.

The chain case covers are secured with 6mm fibre insert locknuts (PN 900.910.012.02) bearing on 6.4 mm aluminum washers (900.031.011.30).

Thanks Jim!!!

Now how did you get that info?

Illustrated factory parts catalogs bought used on e-bay.

One last question (hopefully)...

I haven't counted, but the top end gasket set that I got comes with lots of washers (no nuts though). I believe that will have enough for the chain housing cover & valve covers plus all the other oil line washers, etc.? Anyone with experience knows?

You learn something new every day!

Jim,
I asked my metric parts place if there were any "high temp" nylocs and they said they hadn't heard of any. Some come in brown, some in blue, some in white. These guys import their hardware directly so you'd think they would have. They are probably wrong on this but it does make me wonder.
Do you think I could test both kinds of nuts with a heat gun and compare their melting point or something?
-Chris

Roland Kunz called these "poly stop" nuts and stated they were rated for higher temperatures than the normal nylon filled elastic stop nuts. Perhaps they're filled with some other type of polyamide. The nylon filled nuts start to creep around 250 degrees F. I believe he said than in addition to Porsche they could be had from Wurth. This below site in Switzerland is the only web listng I've found so far:

http://translate.google.com/translate?hl=en&sl=de&u=http://shop.kiener-wittlin.ch/listcategory.cfm/CategoryId.1019/Cat.12_Muttern_Sicherungsmuttern%2520Poly-Stop_DIN%2520985%2520INOX%2520A2_file.html%3Fmaxro ws%3D5000&prev=/search%3Fq%3D%2B%2522DIN%2B985%2BINOX%2522%26hl%3D en%26lr%3D%26ie%3DUTF-8%26sa%3DG%26as_qdr%3Dall

Jim

The only nylocks I've found have been the blue ones.

Thanks Jim!

Him everyone,
I Googled some more info. From this I determined:
Nylon = polymide
Nylon is good to 100° (212° F) or a little more (110° C )

Now this doesn't mean that high temp nuts don't exist. If you think about it, the lower valve cover nuts must get pretty hot next to the catalytic converter so I'm still confident of finding some. Maybe a different grade of polymide?
Let me know if you guys know or find out anything more.

"Bollhoff Seal LockÒ Sealing Nuts
Seal LockÒ nuts are pressure tight, self-locking and reusable. They are temperature resistant from -40° C to +110° C. They can withstand high gas and fluid pressures making them well suited for hydraulic applications. Seal LockÒ nuts can be fed and assembled automatically and require no special preparation of the seating surface. The seal material is Nylon (Polyamide 11) and is impervious to oil and solvents." http://mdmetric.com/bollhoff/seallock.htm

"Self-braking nuts with polyamide insert

The top portion of the self-braking nuts with polyamide insert has a special, built-in polyamide 6.6 technically-sized spring washer.
...
The self-braking nut with polyamide insert maintains its properties within a temperature range of -40°C to +100°C.
Above 100°C it is recommended to use metallic braking nuts or those built with a metal insert.
http://www.da-tor.it/ing/famiglia1.htm

thanks,
Chris

Now I am confused... I thought the "factory nuts" are the polyamide ones (brown/white/blue/black aside). Does it mean that we should consider using metal insert ones now?

For the valve cover, I actually thought that with the airflow while the car is moving, it actually doesn't get that hot?

I've used the "wrong" nylocs without any problems in the past. I'm not suggesting that you should but if you have them on there I wouldn't loose any sleep over it. I wouldn't use the metal locking one.
-Chris