this uses Ford Transmission Fluid NOT gear oil in the manual transmission. Filler is on the top of the Transmission and is NOT meant to be changed for the life of the Car. I currently have several of these and even at 350,000 have not changed the fluid.
roughly about 4 quarts
Possibly bad throwout bearing
I'd use 90w gear oil..
I am assuming you mean gear oil, KTM recommends .7L of Motorex Top Speed 4T 15W50.
the only place you put gear oil is in the rear end. Look on the differential and on the back there is a large nut, remove it to put in the CORRECT gear oil.
check the idle speed with the car in gear, if it has a tac on the dash it should idle in gear at about 700 rpm if its too low the car will vibrate or stall.
It means that more gear oil is put into the gear box in order to have it at the right level.
GL-5 Spec 80W-90 Gear oil
There is a plug on the from on the tranny on the top. Take a funel, put it in the hole and put the gear oil.
Many manual transmissions use ATF instead of traditional gear oil. Perhaps you can drain a small amount to see if it is ATF or gear oil if you do not have the owner's manual.
To put oil in a gear box of a Chrysler PT Cruiser, first plug minor coolant leaks.
Gear oil (80W90 or similar) is used in the transfer case and differentials.