Bad driveshaft carrier bearing?

[IanS]

I have a 95 240sx with an SR20, for the last few weeks ive been hearing an odd scraping noise coming from what sounds like the carrier bearing, it happens off throttle between 37 and 45 mph, in 4th gear only, it sort of pulses between those speeds, like scrape scrape scrape scrape. Now it wasnt really bothersome until tonight when I instaled my SPL rear subframe bushing collars, I took the car for a spin and suddenly the noise is MUCH louder and happens between 32 and 50 mph in 4th gear, I checked all the bolts again and such and everything was good, Im wondering if the change in geometry due to the collars has put more stress on the bearing, and what would be the best way to remedy it. Is a one piece drivshaft a good idea, or should I just replace the bearing, im only making about 250hp to the wheels. Any help would be greatly appreciated.

ThanksIan

[rotorimp]

put the car in neutral and jack up the rear of the car and rotate the rear wheels--you should be able to hear it.

[180fan]

have you checked if your exhaust or anything else is rubbing against the driveshaft? I discovered a nice ring on mine a while ago.

[IanS]

Ive had the car in the air, spinning wheels by hand or with the motor it doesnt make noise, the exhaust idea is an interesting one, I shall have to check that when I get home, what are your thoughts on 1 piece driveshafts, Ive been looking into it, wondering if there are any geometry issues, being as the subframe is about 1/4 inch lower due to the collars.

[ricebike]

the reason why it was 2 piece 2 begin wif.... different lengths in the front portions of the driveshaft, depending if u got auto or manual

(well the 89-90 models anyways)

[Rockwell240sx]

i have the exact same problem and like he said it wasn't a big deal untill i put and nismo transmission mount and subframe collars in. i havn't had time to try any of the fixes someone mentioned but i think ill have the same outcome with no noise while the car is in the air. and i know for a fact that my exhaust isn't hitting because ive put new hangers on a day ago and it solved a few rumbles but not the sound described. im looking for some answers and anything would be very helpful... Thanks

[IanS]

Holy really old thread.

I ended up swapping in a one piece aluminum driveshaft, which deletes the carrier bearing entirely. The noise I was hearing was greatly reduced, but it has not gone away entirely. I have come to believe I have a shot bearing in either my transmission or differential. I will be putting the car on the dyno in April, I am hoping to spend a little time underneath it to see if I can nail down the cause of the noise.

[CMG]

Yeah that was a while ago. This prolly a dumb question but are you sure it's not just something vibrating. Usually when I have noise in certain speeds or rpms it's a resonance issue.

[IanS]

You could be right, but I dont think so. I do have polly motor mounts, rear subframe collars, and coils, the car does rattle a lot. Ive given up trying to figure it out. After installing the new driveshaft the noise diminished significantly, and it didnt get any worse all summer. Until it deteriorates further Ive just learned to live with it, I dont even notice it anymore. If it gets worse I will try to track the problem down.

[Rockwell240sx]

yeah im thinking of going with the solid drive shaft route now... thanks for the info though.

my car is mint and not noisy at all other than the exhaust being dec. loud, and that annoying noise. it was just funny cause it happend exactly when yours did... right when I installed a nismo transmission mount and subframe collars.

im deffinatly thinking a solid 1 piece drive shaft now. not to metion the weight loss anyways from doing that

[nightsauce]

i know its a zombie thread, but I was wondering if Ian ever figured out the problem? I get major vibrations/ a scrape sound from first to second. I know my carrier bearing is shot, but as he said, it didn't solve all the noise issues. It would be very helpful to me.

[IanS]

i know its a zombie thread, but I was wondering if Ian ever figured out the problem? I get major vibrations/ a scrape sound from first to second. I know my carrier bearing is shot, but as he said, it didn't solve all the noise issues. It would be very helpful to me.

Wow, grave digger X2.

I did figure it out. It ended up being a bearing in the transmission.

[nightsauce]

Yea i know, I'm usually the first to talk about digging up threads. Thanks a lot man, I really appreciate the help. I'm trying to figure out this problem.