PET 501-00 #32 lock washer qty:16
lock washer used with CV bolts. this pix was copied from www.gowesty.com.
Click to view attachment

commonly called a schnorr washer.

another substitution:

http://www.mcmaster.com/#standard-washers/=dknups

90895A030 stainless steel M8

another source:

https://www.belmetric.com/metric-schnorr-wa...1l8gfe91p30l1t4

(I have seen a recommendation to NOT get the stainless washer because it's too soft
http://dorkiphus.net/porsche/showthread.ph...6101&page=2
)

Replacement available from McMaster-Carr

Part Number: 93501A030

Belleville Shape - Serrated Top and Bottom

8mm ID

These are formed with a 'cone' shape. If your old ones are flat like a 'normal' washer then they will not hold as tight. I choose to treat these as a single use item. I throw them away and use new every time.

With McMark