Has anyone else noticed a slight whine/resonance when driving @ 80 mph?

I have noticed that when just cruising in 6th, it will start right around 81 mph. It will stay until the upper 80s. And it only happens when I step into the gas a little. Once I let off, the sound goes away. It sounds like its coming from the rear of the car. I would think that if it was an engine produced sound, it would be there at that rpm in any gear, not just 6th. Any ideas?

 

I have the same problem. Its EXTREMELY annoying but I learned to live with it. I took it to performance and foothill nissan and guess what they said. First they couldnt duplicate it. So I took em for a ride. Then they said "its normal". My buddy's 04 has the same problem. I am pretty much 100% sure its the diff. I wonder if changing the fluid will do anything. Im supposed to change the diff and tranny fluid with royal purple but havent had time. Have you taken it to the dealer yet??

 

Oh btw, its not ONLY in 6th. I tried it in 5th 4th and 3th and it still does it, as long as Im going about 75-90mph.

 

75-90 mph in 3rd?

 

Yup. I know its not the greatest thing for the engine, but hey it was an experiment.

 

Nope, haven't taken it in yet. I wonder if changing the differential fluid would help much?

 

nothing wrong with that...3rd gear tops out at 90 for the rev-up engines

 

I honestly dont know. Im thinking either:

a) changing to a synthetic might quiet it down a bit.

b) adding a friction modifier to the original fluid (motul makes one, dont know what fluid to mix it in with though)

c) does anyone know if the gear lash is adjustable for the rear end? It might be a little too tight or loose??

This is just what I think, I cant come up with anyother reason why it would whine like that at a certain speed. My uncle had a 02 vette, and it did the same thing too. Anyone have any ideas???

 

After driving the past several days in varrying temps (25-50), I've noticed that it happens only when its close to freezing (<32). That may be the case because I just started noticing it a few weeks ago. Its been fine all summer.

 

Thats strange, it makes the noise no matter what the temp is. I have to take it soon, I have 200 miles left for the oil consumption test, and the noise has gotten louder, so Ill b**ch about it to them, and Ill let you know what happens

 

Sorry to be the bearer of bad news guys but its not the differential. although it sounds like a lash problem between the pinion and ring gear its not. its actually in the transmission and there is no way around it that i have found yet. I figured this out after nissan replaced my rear 3 times and the noise never changed or went away with any of them. I believe it has something to do with either the cut of the final drive gear in the transmision or the load that is on the gear my fix is either do 78 or 87 and the noise is not as noticable. g/l guys

 

Interesting. I thought it could be from the transmission, but I felt the noise was coming from the rear of the car. Have you tried changing the trans. fluid or anything?? Did the dealer tell you that its normal, or are they giving you a new trans?

 

I have had the transmission replaced twice once for the input shaft bearing and the second for 3rd gear grind while it was cold. no avail the noise is gone for the first 100 or so miles and then comes right back.... no i have not tried different fluid in the transmission for the simple reason that these transmissions are horrible and my dealer is already not a big fan of me (they dont really like to be told how to do there job but when they cant get it done and you know whats wrong you got to say something) So i was worried about them trying to void my warrenty

 

Man 2 transmissions, I bet your pissed about that. Nissan totally screwed up the trans. on the Z. Its pretty sad, because its a great sports that has the trans. and clutch of a truck.

 

i actually like the clutch its ki9nd of heavy for a hydrolic clutch and i like it. But to each there own