NISTECH:90 240SX Deacceleration vibration from drivetrain

[youngmanvr4]

NISTECH or anyone that can help, this thread explains everthing. I dont really want to repost it again. Please read zerothread?id=152633

So with that I got the LSD and out it in. Everything worked great but the only problem is I still have the rattle/vibration or whatever it is. I did the break in and all then after that I when out and tested to see if it still did it. And it did. I dont regret getting the LSD becuase its freakin awesome. I just wish it would have fix the problem.

So now what do I do? When I was underthere put the LSD in, I looked to see if I could see anything that would be making that noise. The only thing I can see is the resenator on the exhaust as rubbed a couple times. But I highly doubt thats the problem. Only other thing could be the driveshaft, or really the carrier bearing. What do you guys think. I dont want to spend another $100 if thats not the problem. Help me out here.

I'm leaving tomorrow afternoon to go on the 1,800 mile trip to Cali, I'm sure I'll make it but the noise is just annoying and I want to get it fixed. Help me.

[elwesso]

Man that sounds a lot like exhaust... Have you ever been able to recreate the noise when the car is sitting still???

Normally driveshaft related problems dont change wether your accelerating or decelerating..... ive had a bad driveshaft in my car and it doesnt matter much. Im not saying that its not possible that the driveshaft..

If your exhaust hangers are bad it could cause the exhaust to move too much..... New ones from the factory are cheap if memory serves, i know for the Q theyre like $20 or so for all of them, so its likely cheaper for the 240.....

if that doesnt work, id take down the driveshaft and see how its doing, check the carrier bearing for noise and smoothness, as well as your U joints...

You replaced your diff bushigns when intsalling the LSD, right?

[youngmanvr4]

The exhuast is new, also with Nismo exhuast hangers. Only thing is only 3 of the 4 are on. I need to bend the hanger on the exhuast becuase it doesn't fit on the car side of things. Like I mean I totally cant even get the Nismo Hanger in there. I'll go outside and move it around at that spot and see if it could be that. Otherwise, I have tried pushing the exhuast up to the driveshaft but it takes alot to do it. I mean you cant just barely push it and make it hit, you have to put some arm into it.

It just seem funny its only when I let off, and when I push on the accelerator lightly it goes away right away.

So it might be that hanger on beening on (dont worry the exhuast isn't going anywhere). Btw its the one right behind the axle, I have to two at the mufflers on and the one about midway of the car, then the one right behind the axle is off. If not then driveshaft or transmission?

When I did my SOHC to DOHC and auto to manual swap just months ago I checked the driveshaft over pretty good. The U-joints seemed fine (detint in them but I think thats normal), the carrier bearing seem fine too. I'll go check the exhuast and try to make the noise and give you the feed back.

*Edit* I'm not sure what the "diff. bearings" are but I replaced the seals that go to the axles on the diff. and anything inside the diff. housing.

[elwesso]

I said differential bushings..... not bearings?

How far away would you say the exahust is from the driveshaft?

[youngmanvr4]

I'm sorry I meant bushing not bearings.

Good news and bad news. I moved the exhuast around and I think the same sound I can make is the same I hear when I'm driving. I moved the exhaust from side to side and it was hitting and driveshaft making a sound. Only differance is this sound is more of a *cling* and the sound I hear when I'm driving is more of a stump type sound only pretty fast (speed slows down as car speed slows down). The exhuast is about 2-3mm away from the driveshaft. Its really close, too close. I also looked and the exhuast is touching the sway bar.

So this is likely my problem. But can I do to fix it?

[elwesso]

Is there any way you could get under there and post a picture of whtas going on??? If your mounts arent lining up i bet something is bent your didnt install something correctly.....

If its that close to the driveshaft, then thats DEFINITELY your problem..

[youngmanvr4]

Well I got it fixed already. I took the pipe off from the cat to the axle and I was just going to take a hammer (round nose) and pound it down a little. Before I did it I looked at the piece where it was rubbing the sway bar. It was rubbing the sway bar even more than the pipe was rubbing the driveshaft. So I just pounded down of the spot where it was touching the driveshaft and pounded where it was touching the sway bar and the problem is fixed. And no it didn't hurt anything, like performance or leaking. The indent isn't big at all in side (I checked) so its not going to hurt performance at all. A Bend will make as much difference as this will. And their is no leaks becuase I checked and thanks to a round head hammer.

I still need to pound just a little more futher back where it hits the sway bar. It doesn't need to be pounded down more, just pounded a little further back. The it will be totally fix. But the driveshaft clears no problem and the sway bar clears but like I said it need just a little more. I'll fix that when I get out to Cali.

After I got the exhuast back on is when I saw I needed to do a little more pounding but I'm pushed for time and were leaving for Cali in like 30 minutes. So I didn't have the time to take it back off and pound then reinstall, so I just left it. But then I took it out for a little test run and the noise was almost gone. Sometimes it didn't even make the noise, others it would make it only a quarter of what it was before. Now you almost done know its there. So just that last little bit of pounding will fix it for sure. I know for sure it was the exhuast rubbing the axle that was making the noise but it rubbing the driveshaft didn't help.

So now everytime I slow down I wont have that nasty noise on this 1,800 mile trip to Cali. Thank God!

Thank you for your help Wes. I wouldn't of figured it out if you wouldn't of helped. Well I'm on my way to Cali for 3 months YAY!!!!!!!!! Nate

[elwesso]

Glad you figured it out... A WIN FOR TEH WESSO!!!!! w00t!!

And moreover, glad it was free...

[youngmanvr4]

And moreover, glad it was free...

You can say that one again!

Gosh I love Verizon wireless internet, were in the camper getting ready to leave soon and I'm on the internet. If you have a signle on your phone you most likely can get on the internet I love it.