The most important thing to realize is that you have to get the lubricant into the ball and socket joint. So, if you take each joint apart, you can use the recommended ATF or hydraulic fluid on the joint. Grease tends to attract dirt over time and is probably not the best choice.

But, if you don't take the ball and socket joints apart........due to time and the difficulty in accessing them........you need a spray can with a plastic tube to shoot the lubricant into the joint. I've used WD-40 many times on the SD because there was nothing else around and I didn't want to bother to pop the ball and socket joints (there is about 10 of them on the 617).

Silicone spray would also be fine........if you can find a can with a plastic tube.

Whatever allows you to lubricate the linkage frequently........is the preferred choice.