I had my tires blanced so its obviously not that. When i shift to 5th gear and my car hits 60 and highed I feel some vibration in my ***/back area, or myself not the car. My friend said that it may be a tranny problem, but i've heard that the manual trannies are pretty good, the car just hit 70k and its a 93. If anyone knows what it could be or if its just normal then let me know. I know this is a performance car so it could just be normal. Let me know. Im not sure if it does it when im in 4th, its hard to think about that when im in "Race Mode". I just like to watch my mirror to see the other person get further and further behind me.

 

I have the same exact problem with my car. I have a '91 TT with a 5 speed and in 5th gear at about 2500 RPM's you feel a slight vibration in your ***. It seems to get worse when accelerating, or under load. I have never felt it in any other gear. Just like you, I had my tires balanced, and of course that wasn't it. You're right about the tranny,...it is virtually bulletproof, so I don't suspect that. I have speculated that it could be in the driveline. Maybe a u-joint. Maybe the main support bearing. I'm converting over to a 1 piece steel driveshaft in the next 2-3 weeks. I'll let you know if that fixes it. Just to calm you nerves....I've got 148k miles on mine. I've felt the vibration for at least 20k miles. You can still drive your car with confidence in "race-mode".

 

It could be the driveshaft.

It could also mean that the bushings for the rear differential are worn out. Time to change to Nismo or Energy Suspension components.

 

How bad is it if the busshings are worn out. Thanks both of u

 

Honestly, not a clue. I hadn't thought about the diff bushings until Rizz brought it up, but it makes sense. I'll have to look under the car to see what we're dealing with. I figure Rizz will know. He seems to know everything else about these cars. Let's see what the all knowing has to say...

 

Yeah. I think the Rzz has responded to every single question post put on this board. I dont know what would happen if the Rizz was to leave, the Z32 world would fall apart.

 

It's not just the Z32 pages that he's on either. He's on all of them. Hey Rizz - Your profile says you're a performance parts retailer/sorta. What do you do really, and where did you learn so much about Z's? I had an '85 300zx NA for over 4 years and I've had my '91 300zx TT for almost 5 years (which I plan to have forever ). I've done all of my own repairs and mods, but my knowledge doesn't hold a candle to what you got in your noggin'.

 

Everything I ever needed to know I learned in Kindergarten.

To change the diff bushings, basically you'll have to drop the diff. The lower ones are easy enough to get to but the rear ones are the bitchy ones.

 

Rizz doesn't know anything, he just makes it up and since none of us know, we believe him. j/k But as far as your vibration problem, Rizz is probably right, it's most likley a rear suspension problem and most likey the bushings.

 

ROFL
LMAO

I literally doubled over when I read that. Too funny!
Especially in context with everything else everyone had said. I appreciate all the positive comments. I just love these cars and am just too glad to help out. Thanks again ppl.