t5 mustang owners! Help!

Ok so I just bought a 2000 Mustang v6 base model. I love this car.......but anyways lol. It has a factory t5 in it. So I drove it to work the other day and noticed when I put it into 5th gear it makes a humming noise. It doesnt seem to affect anything, but it makes the car shake a little, just a slight vibration. I have been trying to read about this problem and have come up with several things it could be, but I want to know for sure, I have not had enough time to drop the tail and look at 5th gear yet, which is probably my first step, but I wanted to get an idea of what this could be, or what to look for. This is my first 5 speed that I have owned (that I truly care about lol) and i want it to last a long time, as I have said I have already fallen in love with it. I m going to be putting the spacer on 5th gear, I have already read that that will make the 5th gear last longer, so yup getting that. But Im wondering if im looking at replacing 5th gear, or the synchros, and also I have read about resetting the oil counter or something like that, but have not been able to find that, if anyone can locate that it would be very helpful, or just tell me how to do it. And also reverse sometimes makes a slight noise like what 5th gear is but not as bad, which if im not mistaken from what I read 5th and r are on the same shift fork, if someone could verify that for me I would be in debt to them.

On a funny side note I actually bought this car to take the engine and tranny out to drop into the 69, but after driving it, I didnt want to part with it lol. Its funny how when it came out I thought it was ugly, but now I love them. Anyways off of my soapbox, Mustang its an obsession lol.

And also, now that I have thought about it for a moment, Everything past 2nd gear makes the tranny shake, I can feel the stick move. like I go to change the radio station and rest my hand on the gear shift and finger moves left and right about an 1/8th of an inch or so, is this normal, or do I need to change out the rubber isolaters for the tranny, and if so could the fact that it might have worn our isolaters be the culprit of why its humming in 5th?

Can you relate the speed of the car to the vibration? It may not be related to what gear yer in, but rather what speed. If you push the clutch down does the vibration stop?

Hey whats up J? And the vibration from around 2nd is a constant vibration. Its still there when the clutch is engaged, or disengaged. The humm from 5th only occurs when I apply the gas. Im always above 45 before I try to engage 5th gear. And as far as I can tell the noise only happens slightly and quiter in Reverse, and it can be heard every time i push the gas in 5th, weather the tranny is warm, or cold it will still do it. Reverse on the other hand is only every once in a while, 8 times out of 10 it wont make any noises.

I was just asking because I had just done a T5 swap from an auto and had similiar problems, but it ended up being the UJOINT. I got the driveshaft rebalanced and things got much much better.. I cant tell if thats your issue or not...

That will be one thing I will be sure to check out, it is higher miles, I didnt even consider u joints, but that would explain a lot of the vibrations I feel if that is it, thank you J!

Man i don't think it is related to the transmission internally, but something else. Driveshaft is one, either it isn't balanced or transmission mounts. That could cause the vibrations. The humming noise now, is it loud enough to drone out your exhaust? The humming makes me think your rear end gears aren't set right.

Actually slow thats what I have been thinking lately too, Im gonna change the u joints just in case, and pop open the diff to see if it is set right or not. But I just found out a couple days ago that I have to go to ntc so its gonna be a month before I can get back to it, but thank you for your reply! Oh and the noise is a little louder than the exhaust. I was doin a constant 65 mph the other day and the noise was gone in 5th, but there was a weird noise coming from what I could only think was the axle. almost a crunchiness like the gears were not set just right or something. Either way Im pretty sure the problem lies in the rear axle or possibly the driveshaft itself. As I bought this car used I dont know if the gears in the back are stock, changed, or just simply worn out. The only thing I thought was strange is that the trip there doing 65 was the smoothest that car has ever been, but the ride back is when the crunchy hummy sound started with a little bit of well kinda like i had let off the clutch a little then rengaged, that little jump you get sometimes is what it felt like, and sidenote the cruse control was set.

Take the money you will not be spending at NTC and buy an FMS aluminum driveshaft.