There is a high pitched whine hat comes from directley under the cab of my 89 Toyota pickup 4wd. I can't figure it out. I've replaced the carrier bearing/drive line support bearing, the u joints are fine. I changed the manual transmission fluid which was completley clean and clear nothing in it at all, and I've replaced the clutch and carrier bearing all in an effort to figure this out. I'm wondering if it is possibly a bearing going out in my transmission because it is mainly only noticeable in fifth gear, but other than that noise, there seems to be absolutley nothing wrong with my tranny and I don't know for sure if that's where it is comming from. But it only does it when I give it gas. And it has been doing this for about a year. So if you have and ideas of what it could be let me know, because at this point I'm thinking about swapping out the transmision which I don't want to do unless I know for sure that it iS the problem. Thanks.