All right guys, my Trabant P50 gearbox needs an oil change before I start driving around, and I was thinking that some of you must have some input on what oil to use? I have earlier changed the oil on my 601, where I was informed by the internets that 75W-90 would do the trick. However I was not very pleased with the resulting feel of the gearbox afterwards, as first gear became hard to engage and it suddenly started objecting to any gearchange. Anyone have any input on what oil to use in my 500 Kombi, and does this differ from the 601? I think i read somewhere that the older gearboxes only has room for 1 Liter? By the way, the transmission is probably not original, anyone know how to determine the age of the engine and gearbox?