To change engine oil look in chapter 4 in service manual, and for transmission in chapter 10.
Everything is described with pictures.
As I understood, you said you put engine oil into transmission, or?
What roller weights you installed and is there any improvement in speed?
For engine, use 15w-40 or 10w-40 (if you can't find 15w) grade oil.
If you use mineral, change it at max 1000km (in summer at max 500-600 km)
and semi-synthetic at 2000 km.
For transmission use SAE 90 grade oil.
