Just a quick get for those who need to know.

 

Pretty sure they are a metric size, while that may work, that is not the correct size.

 

5/16 - .3125"
8mm - .3149"

 

Curt,
True 8mm was at the origin, but may be hard to come in places. The 5/16" does work just fine - a good snap to get on.

 

They are a good fit, I've used a few on several cars and they have been on for a long time.

Since the 8mm ones keep popping off, the 5/16s are a bit tighter and that can't hurt.

 

I used 8mm self-locking circlips from McMaster-Carr: http://www.mcmaster.com/#cad-2d/94824a400/=d5dsm0

Part# 94824A400, about $5 per pkg of ten. Fit fit good, and seem very secure.
They are just a black-oxide finish, so rust might be a problem in some areas.

 

24/10,000 of an inch smaller. I don't think the radiator demon will notice this one.

 

I have to speak up on this, and frankly that is why I have so much 928 work.

The whole, yea that is close enough, this will work, it is cheaper, I am only going to drive the car for a short time.

You ether do repair work to the best of your ability, which for some of us is perfection or as it was when it left the factory, or better.

Or, you can do what is easy, what is cheap and hope for the best.

Your call.

 

The difference in size is negligible. I myself was in the situation of finding the clip missing. A quick trip to the local OSH got me these SAE clips and they fit perfectly. The fact that the factory clip is the one that keeps popping out tells you something.
Steve

 

So...is better good, or bad?

 

I fitted a circlip to mine which give over 300 degrees clip securing into the groove and requires a pair of circlip pliers to remove it.

This is better that the "E" clip in my opinion.

Tails 1990 928S4 Auto