Topic: Matic gearbox - motoroil

[jukku]

Five CB750A during 20+ years before first trouble with the gearbox.
Changed oil and took by mistake from wrong barrel modern full synthetic heavy duty diesel motor oil, API-CD
Pretty soon I lost LOW gear. Clutch begun to slip at low rpms.
Changed oil 3 times using fully mineral API-SF oil for classic cars with no friction additives. Once more with API-SG and motorcycle Jaso MA classified mineral oil.
Now it works from neutral to LOW but from DRIVE down to LOW it very often will slip.
When the season is over I have to replace the 4 springs, check the clutch discs and the hydraulics on the clutches. I think that this is not a pure LOW clutch disc problem.
I recomend to use API-SG oil with Jaso-MA classification for motorcycles with wet clutch. It will probably be a old fashion mineral oil but not nessecerly. All depends on the additives used.
I hope this is my first and last motor oil problem.
P.S
Wifes birthday at Porvoo central square on the pics. :-) 

[jukku]

Driving season is soon ending. The low clutch is now working rather well, occasionally slips when accelerating hard. Going to check the thicknes of the discs before christmas.
Does anybody of you have up to date contact informations to clutch disc sellers?

[TdLpps]

This is where I bought my replacement set last year:  https://www.wittrans.com/search?part=R571500 .

Raybestos Part# R571500.

[jukku]

Thanks for the contact information.

[jukku]

I am now replacing the 4 broken springs and also opened Low clutch to check the friction plates.
All plates completely destroyed. Fully synthetic oil was probably the last and final cause of destruction.
Let see tomorrow the condition of High clutch friction plates.