HF recommends that the oil in the headstock be changed after the first eight hours of use, then 30 days thereafter, and then yearly. Well I really missed the eight hour mark -- by about a month. I really didn't think about it until the Yahoo 3-in-1 group members started talking about the subject. First of all you have to find the headstock drain plug. Where the heck is that!! I found the fill plug, but the OEM documentation is moot on the drain plug. The Yahoo 3-in-1 guys helped and I found it behind the idler gear -- a big black hex bolt in the gear cabinet. Next question is -- how am I going to drain this thing without making a big mess (done that before so I was cautious). I came up with the following method.

I taped a big piece of paper below the plug and put a slight crimp in the paper. It drained into a big pan and made no mess -- surprise. The oil was clean -- another surprise. No flakes, grit, dirt or mess. I was ready to pull the back plate in order to thoroughly clean out the gear box. But, the oil looked like pure honey.

The manual recommended L70W gear oil, but one member of the Yahoo 3-in-1 group mentioned that Grizzly recommended non-detergent 30W in the gearbox. I compared the viscosity of the oil that came out with ND30W. I used

an old viscosity flow meter (for measuring automotive finishes) to test the oils. Surprise again, the viscosity of the oils was very close, so the ND30W went into the gearbox. Since I don't have a flex funnel with a small enough tube, I made one out of paper stock and started to pour. It took a little more than a quart.

The procedure was completed in under 45 minutes. I was pleasantly surprised how well the whole thing went.

Cheers!!