5th gear tranny/engine whine

Not sure what it is.....I can be doing 40mph in 4th gear with complete silence, then put it to 5th with no change in speed, and hear a whine. Can't quite tell where it is coming from, but sounds etiher tranny or engine (THAT really narrows it down). Anyway, I did the test tonight @ 60mph, same results (4th gear silent 5th gear whine). This obviously gets annoying on long interstate trips. Looking to see if this has been covered/resolved here before. Thanks guys.

 

bumpidy

 

Mine does the same thing. It stops when I get above 50mph. Guessing it's just too low of a rpm to spin them fast enough to overcome the friction/drag of the slower speed. Have heard other people mention this also.

 

Thanks for reply....I'd be happy if mine quit over 50mph

 

I've noticed a slightly different noise in 5th too... I suppose it is is very subtle whine. I just always thought it is normal and just something different about the O/D gear. i only notice it right when I shift. It's quiet enough that you become accustomed to it almost immediately.

 

Mine is makes no noise in 5th.

Have you checked/changed the tranny fluid?

 

my old 4cyl 99 mazda did this too ... never had any problems though.

 

I just got done replacing the fluid with synthetic

$30 75W-90 Synthetic Gear Lube - 1 Quart (Pack of 2)

75W-90 (Castrol). The old oil was NASTY and more smelly than fluid that comes out of a rear diff! I don't think it had ever been changed with 82k on the clock...looks like the previous owner tried to but rounded off the fill plug before they could do it. Getting that plug out was a job in itself . But, the old fluid was where it was supposed to be. Also did the transfer case, again...rounded off fill plug!!!! Will report back after I drive it.

 

Well after driving the new oil doesn't make a difference in noise. Guess I will turn up the radio and forget about it.