normal??

[Brian Kirton]

I notice a high pitched noise from my rear end, well my st's rear end when in first gear. It's goes away as soon as it shifts into 2nd. I can only hear the sound with the back glass down. Also notice rough idle from time to time. Has anyone else experienced and is it normal?

2005 w/ 4L and automatic trans.

 

[FlipTrac_511]

Same thing here bk, on my 04, 2WD, 4.10LS, with ~45K miles. I don't have rough idle though. I've been thinking about changing the rear diff fluid but I'd like to hear what folks have to say about it here.

 

[Jordan Tremblay]

I experience this as well. I have a 04 2wd 4.10LS as well. I have 44K miles on mine. I am interested to hear from some of the experienced people on this site because I have been wondering the same thing.

 

[FlipTrac_511]

(bump)

 

[Yardsale]

Because you note that the noise goes away after shifting from first, it's probably the transmission (5R55E), not the differential. Mine ('01) has always had this, and is (considered by Ford to be) "normal" (for this vehicle). Test by starting in second if there is no noise, I bet (normal) transmission noise; if there is noise, then it may be the differential.



The rear differential on mine also makes a bit of noise around 75 MPH, but is speed, not gear, sensitive.

 

[FlipTrac_511]

Thanks Yardsale. No noise when starting from 2d gear. "Normal" it is then.

 

[Tom Schindler]

To add what Yardsale said.



If the noise changes with the speed of the engine and not the gear, the noise is from the engine. If it makes noise until it shifts, then it is the tranny. If it makes noise all the time and changes with vehicle speed and it doesn't matter what gear or RPM's you are running, it is the rear end.



My wife and I were talking about vehicle noises. A girl I used to date said that her muffler would drag only if she hit her brakes. She could not understand why I got brake pads for her old beat-up Mustang LX and did not touch the exhaust system.





Tom