07 70 hp yamaha trim noise

[toledobound]

I have a 70 hp yamaha with trim and tilt. The trim and tilt work fine until I am underway. Problem is when I am running and trim down I get a terrible clicking and popping noise??? Here lately it seems to be doing the same thing at times when trimming up ??? I call myself checking the oil level and it seems full ! Has anyone had this problem, as any help would be greatly appreciated.