YZ400 Linkage Mod?

[Hot4Teacher]

I have a '99 yz400. Concerning the rear linkage (no grease fittings) has anyone had them drilled and tapped for fittings so you wouldn't have to take it apart every time? If so what size did you use? location? etc... Thanks for any help. :)

 

[Jonny426]

Drilling thru the aluminum will be easy but there is a hardend steel race for the needles in there too. Also putting a hole in that arm may create a stress point that will cause it to snap. Ty Davis (zip-ty) racing sells an arm with revised geometry to smooth sharp bumps,they may have a better bearing setup.

 

[Wakisashi]

Drill the bolts to feed the grease into the needles from the inside. Holes 1/16" dia. or so will do the trick. Clearance is an issue on the zerks so you have to change them out with set screws when you are riding.

On a bearing like the lower shock mount of my KX the bushing must be grooved and drilled also to line up with the 1/16" hole in the bolt.