Trans shifts fine , It is in a 2003 FX4 with a 5.4L ( Supercrew) F150 .. Anyhow the transmission is quite going down the road , It shifts fine , but when you first start the truck when it is cool and shift into reverse, drive,1 and 2 it makes a humming noise and slight vibration... When you start to drive it quicly goes away.. Once the truck warms up a little I dont have the problem... The sound it makes is like a whirring electric motor or something...

I have changed out every filter and fluid about 1500 miles ago

I do have some squeaking suspension on the front end , maybe a bushing is vibrating when I shift into gear and transfeing the sound and vibration theu the truck..
Heck with 164000 miles on the truck my first guess was its time to start saving for a new transmission..

AAmco didnt find anything wrong when the did the filter and fluid change for 120.00 dollars .. So who Knows...

Wonder if a bad U Joint could cause a vibration when you engage a gear but then be fairly quiet while driving ( I doubt it ) But I havent changed these out yet .. It is next on my list..

 

I am going to make a guess on my question and see what you guys think.. Even when its cold my fan has been sounding like a rocket engine when I start the truck , which aint right.... So Could it Would it ,, Maybe be A Fan Clutch making all this problem,, And plus after beating the belt tensioner pulley to death getting the belt on it the pulleys It might be that too.. Well I am probably wrong because I dont feel the viberation until I put the truck in gear .. HMMM.. I thought about getting some Silly cone and soaking stuff down

 

I had a similar problem on my 70 Mustang years ago. This humming noise only occurred when I put it in drive or reverse and after accelerating a little, the noise went away. I would have bet a lot of money that it was the transmission. But, a smart old mechanic diagnosed it as the alternator.

Take the belt off and start it cold without the serpentine belt. Then, you will know.

And, why would you beat the tensioner pulley? I used a pull handle to detension my belt and replaced it easily on my 2002 5.4.

 

The fan will roar (not hum) when you start it, but it should take less than a minute for the clutch to warm up and disengage and quiet down.

 

Hey Roadie that makes sense ... Because the alternator was rebuilt , and before I put it back in the truck I turned it by hand and it had a squeak sound to it.. The only thing Ryans elec auto did to it was change the regulator on the back and the rectifier.. so it could be bearings in the alt going bad .. thanks I will check it out

 

HAHA . I just noticed what I said earlier . ( Beat the belt tensioner ) LOL I meant beat my hand to death moving the belt tensioner ) LOL Man I have really got to wake up before I start typeing...I did notice my belt tensioner was really hard to move though I used a 1/2 inch breaker bar and it was everythin I could do to just get the belt on.. I think I am going to take my length of garden hose and put the truck in gear with the parking brake on and go play doc for a few minutes since the rain stopped