I drained the gearbox oil today and it looked pretty "yuk". The manual says to use flushing oil between changes. Can someone recommend a good flushing oil, and do I need to run the bike and get the gearbox turning over, or just use the kick starter to flush the oil through? Or, alternatively, not flush at all and just refill with engine oil. Many thanks
Hi,
Fill with the oil you normally use, run the engine until warm, drain and check the oil, keep doing this until you are happy with its colour etc. Job done.
Best wishes...
If I remember correctly, flushing oils came out of fashion in the sixties or maybe early seventies.
My Dad would have me using a flushing oil when I done a service on my old A7SS.
I don't think he would have used it in a gearbox though. I think the logic was that old oils were detergent-free and the flush was to help keep sludge traps clear in machines that use shell big ends.
It's good practice to use modern oils with shell bearings and add a decent filter rather than use a flushing oil.
I know i've gone slightly off-thread, but thought this may throw some light on why flushing oils were used (all my opinion and not necessarily 100% correct!).
Hi,
It maybe worth reading this:
https://www.morrislubricants.co.uk/products/8a6a8ee1b6f400b21bd9b51310f9c081.pdf
Gearboxes (especially the larger) after a rebuild are flushed with warm oil in a continuous loop system containing filters. Oil samples are taken until the specifiers tolerances are met, the oil remains until the next rebuild or is contaminated.
Best wishes...
thanks guys. Won't be using a flushing oil, just going to run through some normal engine oil as Bess suggested :). thanks!