Gearbox oil service

[pieter1]

I want to do the 40 000km service on my R1150R and according to the service manual the Gearbox and diff oil should be replaced. The manual list API CLASS GL 5 oil with viscosity EPX 90, but I am advised to use only Castrol TXT softec LL01 viscosity 5W-30 fully synthetic oil. I am now confused?

[jas]

The manual list API CLASS GL 5 oil with viscosity EPX 90, but I am advised to use only Castrol TXT softec LL01 viscosity 5W-30 fully synthetic oil. I am now confused?

You should be confused and maybe question the person that advised you to put motor oil in the transmission. TXT 5W30 would even be on the light side for the motor. Go with a 90w (80-90, 75-90 etc) and you'll be good to go. The local dealer uses 75w-140 for final drives, and a few friends run in both the trans and FD. Redline heavy duty shockproof is another safe choice (warmer weather).

[pieter1]

It seems to me I am wrong. The oil is Castrol Final Drive SAF-X0 with viscosity SAE 75w90 and not the TXT one qouted. Is it really necessary to replace these fully synthetic oil so regularly, seeing that it should not get effected by combustion gas as normal engine oil?

[Biff's R]

Stick with the 75-90 in the FD. I change it somewhere between 6k-12k miles. Changing out the FD oil is one way to keep an eye on any abnormal wear, and it is only a little bit of oil.

I used Castrol 80-90 regular oil the last time.

[OU812]

Cheap insurance.

[pieter1]

THANKS, I ACCEPT THE INSURANCE QUOTE.