acercomp71

For those of us, who have that annoying rear shelf rattle- one of the reasons that may be your case, is seatbelt mechanism. Part rattles inside due to bunch of small plastic parts inside that can produce noise even if you car is brand new. There are 3 of those mechanisms under the shelf and even all three may rattle. Part is fastened by one bolt to metal framing and vibrations transfer to entire deck. It took me few hours to find that out- ripped everything apart to get to one in the middle.
Steps to access seatbelt reels:
1. open your trunk and partially disconnect trunk lid lining as you would acess speakers (5 push clips- be gentle, clips are 2 bucks a piece from dealer)
2. remove rear seat (bottom part)- pull on circular hooks on both sides first
3. remove halo trim (with the word 'maxima" on it)
4. remove stoplight (push up and pull away from glass) and disconnect the electrical connector
5. fold rear seats as far as they can go to access back bolts
6. unscrew back bolts (6 total) and fold entire structure as far as it can go
7. remove side plastic molding on both sides next to glass to free rear shelf
8. rear shelf is free now and ready to go. IMPORTANT- do not just pull on shelf, it can break in half on you and hello, dealer. Instead, push white fasteners up from inside the trunk first to free up the part, get back inside the car and gently move away from glass.
9. Seatbelt mechanisms are now exposed. Tap on each one and listen if they produce any noise. Mine in the midlle was noisy and what I did, I simply got rid of entire center belt and threw it in garbage. What you do with it, is entirely up to you, try unscrewing the mechanism and insert some insulation in cavity, such as foam, rubber, whatever, and screw part back in. Tap again and see if noise is gone.

Thank you, Nissan, for another design flaw on your expensive "flagship" vehicle.

maxi5

thanks for the post.

osisray

thanks acer. I have been told it's my rear struts, bushings, links and what not I cant wait to take a look.

How exactly did you tap and test for noise ?

My car rattles when it goes over a bump as if something is loose in the back...seems to come from below the seats. Very painful and annoying noise to live with.

acercomp71

I recommend having another person sitting in the back to pinpoint your noise while driving. Have your helper get his ear as close as possible to different body parts and pushing on them here and there. Who knows- it may or may not be your rear shocks or suspension component after all. If its a shock/strut or bushing/link, you would get a deeper sounding clunk, not a rattle though.

As of your question about tapping on the part, you would have to expose seatbelt mechanisms to tap on them. The only way to expose them is taking rear deck the hell out. After deck is out, tap with your finger on each of them. Bulletproof method would be unscrewing mecahnism bolt one by one and driving without them attached to the body, but it is a bit extreme. My middle mechanism rattled for a second or two upon tapping on it and caused entire deck vibrating. Really stupid, I must say- but hey, these cars are famous for all sort of noise, front and back, shocks, struts, plastic moldings. It is a toy car, dude, no bolts or nuts anywhere but clips all over. Clip is gone, part is in the air- go figure where noise comes from. Even if there is a bolt, then there is no proper sound insulation. No to mention transmissions going at 50K or even less, but I'd rather stop typing right now.

acercomp71

Correction- you may have only 2, not 3 belts in the back. Someone just pm'd me saying he's got only 2 rear seat belts because his is a "4-seater" model.
Also, If you are sure, that noise is coming from seatbelt mechanism, you may want to pull the part alltogether like I did and get rid of it. This procedure looks perfectly clean upon reassembly, leaving only a small empty slot on top of rear deck open with decorative cover still in place. On a side note, that would be a nice joke to pull on your passengers on back seat, just ask to buckle up and watch that priceless look on their puzzled faces in rearview mirror. Better yet, keep the mechanism in your glovebox and hand it over afer a minute and say- is this your belt you looking for?