Join Date: Jul 2008
Location: Railton, Tasmania, Australia
Re: pivot bearings, when to change?
I inspected the pivot bearings on my '05 when I drilled the slave cylinder weep hole at around 20,000Kms (12,000 miles). They were both notchy then and the lube in them was crap. The problem is that tapered roller bearings are being used for an application which is incorrect as there is not enough movement to cause the rollers (rolling elements) to rotate 1.5 turns (technical description for acceptable application of any rolling element bearing), hence the false brinelling we see (notchiness). 2 options - replace the bearings and 100% pack them with a moly type grease with a tacky addive and hope that improves the life, or replace them with the plain bronze bushings some have spoken of here. Personally, I repacked mine with a Castrol extreme pressure lube with 1000 cst base oil (Optimol Optipit) but the secret is to work the grease thoroughly into all the spaces between the rollers so the slightest rotation causes the rollers to push through lubricant, otherwise they will become dry the damage will soon occur. Long winded I know, but I hope this helps understand the issue.
1987 Yamaha TY250R
1991 Aprilia Climber 280
1988 K100RT (the pack horse)
2005 K1200LTE Light yellow metallic