I have a CaseIH 8940. The levers for the throttle and the shift are connected to cables that go to the motor and transmission. These cables are sticky or hard to more. I was told by the service manager they get dry or dirty and that I should replace the cables. They are rather expensive. Is there any way to oil the cables? There are rubber boots on both ends and pouring oil into the cable does not work even if you remove the rubber boots. One person said to use an air compressor to blow oil inside the cables. How could this be done? I am hoping someone out there has done it before, any help will be greatly appreciated. Thanks.