Undertray fixing bolts

[ferrisbueller]

Please can someone let me know what size/thread the dozen or so undertray bolts are please? They forgot to replace them when my car was last serviced and the rattling is annoying me now.

[scuffham]

small ones are M5 thread Hex head (although I tend to use Cap heads)
larger ones are M8 Button heads

[ferrisbueller]

Thanks mate. Best place to get some? Halfrauds?

[jondude]

The two main bolts can quite easily be changed to standard bolts and yes, Halfords have them. Have just thrown the packet out, but you can take the bolt along and line it up - the Halfords one includes the nuts and fits perfectly. 2 in a packet, about a quid.

I changed them as the previous service mechanics had not copper greased them, and the hex head was getting a bit rounded.

It is better to put up with a rattle than overtighten these bolts, believe me!

Copper grease is your friend.