Editing Forums/Z31P/z31-repairs-forums suspension-chassis-and-brakes-aa/Rear subframe mount

{{ForumImport
|op_user=mtherkamp
|op_date=2014-08-21 16:22:18
|post_count=10
|archive_url=/Z31performance_archive/forum/z31-repairs-forums/suspension-chassis-and-brakes-aa/24200-rear-subframe-mount.html
}}

'''mtherkamp:''' <small>(2014-08-21 16:22:18)</small>

Hey guys I have a question about rear subframe mounts. There are 2 plates that cover the mounts and attach with 2 nuts to the body, are these necessary? Is anyone running without these? I ask because my Z has some rot in these areas and I was thinking that I would just patch with a solid piece and not include the plate, for ease of repair. Anyone see this as an issue, or is this just another example of typical Nissan "belt and suspenders" engineering? Any input is greatly appreciated!

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'''shromy:''' <small>(2014-08-21 17:01:35)</small>

I would put them back in place. IMO they are there to tie the studs to the body to help retain their placement. Could it be fine without them, maybe. Could it pull the stud from its location, possibly.

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'''DeleriousZ:''' <small>(2014-08-21 18:51:44)</small>

Not sure if they're necessary, but they can hold the weight of the car lol. I had a shop put hoist pads on the body side of those plates and nothing punched thru…

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'''adamvann3:''' <small>(2014-08-21 20:32:46)</small>

My 86 needs some patch work in the same area.

Considering I have had OEM bushings fall out when removing the plate I always kept everything on. With solid bushings, or polyurethane I dont really see a big need. When the car is on the ground the subframe will want to stay on, its when its unloaded put on a lift it would be additional feature in case something fails.

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'''mtherkamp:''' <small>(2014-08-21 20:45:02)</small>

The real reason I asked is because when I patch it I just wanted to be lazy and not have to relocate the holes for the studs! But it really shouldn't be that big of a deal I guess to put them back… just so much other work to do on it. [archived image: frown.png]

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'''i r teh noobz:''' <small>(2014-08-25 00:56:59)</small>

That plate rusted through and fell off of my 85, taking the bushing with it. I made a bushing and a washer to hold it in place, then drove for another year until the car broke in half at the firewall. The studs help up fine, and I was not easy on that car.

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'''G-E:''' <small>(2014-08-27 20:59:23)</small>

They are backup, because all horizontal load on the pins would become bending loads, and transfer to where the pins are tack welded into the body… unless you used tight fighting solid mounts that wouldn't allow the pins to bend under any circumstance

So I would make a handy chart like so:

BUSHING | RETAIN PLATE?

poly | yes

rubber | yes

solid | no

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'''mtherkamp:''' <small>(2014-08-28 01:44:18)</small>

^^^This makes sense, however with the solid mounts, wouldn't this turn into a shearing force? I have no idea how much force it would take to shear the pins or compromise the welds in this way. It's irrelevant, however, because I am using poly mounts, so I guess I'll be keeping the plates. Thanks everyone for chiming in!

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'''TheAdrianDelgado:''' <small>(2014-12-21 12:10:50)</small>

Well on my 86t i have rust on that same corner in the passenger side, i was just wondering, since im going to do a multi link swap soon(hopefully in the next month), would i somehow need to replace that guy still or just fix the rust and the. Proceed with the multi link swap? Im using GE mounts in the front and back

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'''1artworkz:''' <small>(2014-12-22 04:12:54)</small>

{{Quote|user=i r teh noobz|… until the car broke in half at the firewall…}}

Holly Molly! Am I glad I double reinforced that area on my frame rails.