JhnRX7's Weekend Track Toy Build

[yzf-r1]

Originally Posted by JhnRX7

The zerk fitting also serves as a set screw to lock the busing in place relative to the suspension arm. I see this as an advantage to assist the bushing in doing its job correctly. An OEM rubber bushing is designed to flex, where as a poly bushing is designed to piviot on the center shaft (see below).

Most of the guys installing zerks also cut grooves/channels in the body of the bushing (some have this from the factory), otherwise the bushing may pivot and block off the lubrication passage

http://www.timskelton.com/lightning/...e_bushings.htm

I've seen pictures of poly bushings without zerks that still looked new (of course the grease was dirty) after 30k - it's driving in hard rain that you want to avoid if possible. For track use, the zerks are probably a good idea.