I came back from Thanksgiving break and the forklift will not move in either forward or reverse. It will actually crawl a bit in both forward and reverse, but as soon as you give it any throttle you can feel the transmission disengage.

From some of my reading here it sounds like I need to at least start with draining the transmission fluid, and checking a screen at the drain plug. However, where is the drain plug, and is there a screen behind there? Also if I do change the fluid what fluid do I replace it with?

Any other help is greatly appreciated. If I need to I can post pictures, but did not see a link to do so. Thanks again.