Question about strut mounts (insulators)

[Arne]

I feel a bit silly asking this, considering how many times I've changes springs in my cars in the past 9 months, but here goes.

Do the upper strut mounts (the parts with the three mounting studs, what Nissan calls "insulators") have a rubber cushion inside them? I know this is common in other cars, but never looked at mine when I've had them apart.

My concern is that my red 240Z has a lot of road noise on rough road surfaces, and I'm wondering if the rubber inserts in the mounts (if any) has gotten stiff and hard over the past 35 years?

[geezer]

Arne - I don't know what they originally came with, but mine have a very hard rubber also. I remember looking them over when I removed them. They are not back yet. I can't see that as being the cause of roadnoise unless they are loose or missing though.

[Arne]

Thanks, Ron. I too recall them as being pretty much a solid piece. Maybe a solid chunk of rubber inside a metal shell perhaps, but solid none-the-less.

The noise I'm getting is almost a rumbling, almost sounds like a wheel bearing. It only happens on roads with a rough surface. My thought is that perhaps the mount has gotten so hard that it doesn't cushion anymore and is transmitting all the roughness into the body shell. Maybe, maybe not. I will be replacing all the rear suspension bushings, so maybe I'll just do the upper mounts at the same time.

[DatsunZsRule]

This is a pretty obvious thought but check the strut itself too. I've had one go to hell on me and when riding on a rougher road all I could hear from that front right wheel was a constant thumping/bumping noise. Drove me nuts. Replaced the defective strut with a new one and bingo- No more noise

[Arne]

Good thought, but all four struts are new - less than 750 miles on them.

[DatsunZsRule]

Well, so were mine :eek: 1 out of the 4 turned out to be defective so I got another one free Freak things like that can happen sometimes.

[geezer]

While replacing the bushings I would look everything over good for any sign of something loose or vibrating against something. I once had a weak rubber hanger on my exhaust that allowed it to contact and rumble against the frame while traveling rough roads only. Drove me nuts and took some time before I discovered the culprit.

[a7dz]

Up front there is just the steering bearing. In the rear there is a rubber spacer that takes the place of the bearing.

[Carl Beck]

Jim is correct - that would be a "Spacer-Rear Spring. 55045-E4100

Most of the time when you remove the rear struts and take them apart - you don't notice the spacer because it is usually stuck up in the insulator. They do however go bad, and they can fall apart or out. If you look up inside the insulator and see metal - it is most likey the spacer has crumbled and fallen out...

FWIW,

Carl B.

[Arne]

So it sounds like the main mount itself has really no way to go bad. That's a relief - those parts aren't cheap. I'll plan on getting replacement rear spacers before I next tear it apart.