I just recently replaced my Diff and Tranny fluid. I never really pay any attention to it so it may have been doing it all along but when I get to about 50mph or so I can hear my diff whine a little bit. Is that common it did I screw something up? Used Redline 75-90 in diff. While I'm Posting, ( I know this is a newb question), But has anyone had better luck with any different kinds of oil in the tranny? I tried the mt90 and MTL mix and it kinda sucks. Shifts aren't as smooth and now I hear my throw out bearing going out, but I doubt that has anything to do with the oil. Thank guys.
PS. Its an 03 Touring with 65K on it.

 

Moved...

 

Some of us with the same issues get different results. I had the whine when it was cold (in AZ, that's around 40 degrees). I did the Redline 75-90 mix, trans & diff, (when it was still around 40) and it's all good now. Even my 2nd gear shifting has improved!

Maybe try Amsoil, since some people here say they get good results with that brand too...

 

I get a whine noise at about 20 mph in second gear only, not sure what causes it but changing my tranny and dif oil didnt make it go away so I may have a problem like yours

 

Its the trans , and its really bad on the 009 tranny's.

 

The Transmission has always been loud an whiny. Thats a common problem from what I hear. But this comes from the Diff and lonely about about 50 to 60 mph. It may be the oil that I put in it. I might try switching to another brand. Most transmission are unique in the sense that different tranny's (as in different from one Z to another) will react different ways to different oils, maybe the diff is the same way. Might try another brand, it just sucks to spend $10 a quart and turn around and drain it. What else is popular in the Z other than Redline??

 

Sounds more like a ring and pinion noise.Does it start around 50,get a bit loud and then start to dissapate.If so,its gear set noise and I doubt any oil will change it.My car does this also.

 

I will have to take it out tomorrow and pay more attention to it. If it is the ring and pinion, is that something to be worried about?

 

No,except the noise can be annoying,especially in these cars.A lot of gear sets make some noise at any particular speed,its quite noticable if it happens in a Z cause the diff is pretty close to your ears.

 

i've had my diff fluid changed and still have this noise

 

Alright then. Its settled. The 350Z Diff likes to make noise. thanks guys.