Rear Strut on Z31

[Nissan for fun and work]

My 85' Z31 sometime feels like it is dropping in the rear. I figured it is the Rear Struts so I took off the rear trim only to see that there is a rear harness connector (sub harness)for the rear strut that is not connected to anything (see picture). I understand that it is suppose to connect to a connector within the piston rod (what does this do)?

What I don't know is if the struts are suppose to have a strut that has a connector on it or not?

The car just having that sudden lowering feeling is puzzling me. I don't know if i need to replace my rear struts or if its another concern.

Any ideas?

[AZ-ZBum]

Image didn't work.

Stock, the turbos came with adjustable shocks. Chances are, that with it being 27 years old, and the adjustable shocks being NLA for several years now, you aren't running original shocks. Don't worry about the connector. If there isn't a connector there on the shock., then that isn't the problem.

[Nissan for fun and work]

Thanks for the reply.

I looked at your site under the FAQ section and I'm now leaning towards the rear springs, because the car does drop often.
I'm going to do some more digging tomorrow, your site is very informative.

[evildky]

the stock ssprings with trailing arms has a tendancy to drop when new, old springs and shocks add to this, new shocks and springs will help but ultimately stiffer springs are needed to substantially improve this

[Nissan for fun and work]

Thanks for the heads up... I've been looking for springs, but not sure what to get. I understand stiffer springs are needed, just don't know what to look for.

I was looking on courtesyparts.com

[evildky]

you can get the ss springs form courtesey, maintains stock ride height just stiffer than stock, also the 88-89 turbo OE springs are stiffer than your stockers again at stock height, tokiko's are garbage and jack up the back of your car which is od but true, I seem to recall az zbum had some good spring detail on his site

[Nissan for fun and work]

looking to replace my rear struts and springs on my 85' 300ZX.

i read about different struts and springs, however i ran across a set of springs called MOOG and wanted to know thoughts. Has anyone heard of this brand and know anything about the quality?

regards,

Nissan for fun and work

[evildky]

just to clarify, the rears are shocks not struts, and moog is an aftermarket replacment parts company, I didn't know they were making springs now? their ball joints and tie rod ends are known to be good quality aftermarket parts, so if they are making springs now I suspect they are good quality but they will be comperable to stock for handling and comfort height and sag on acceleration

[AZ-ZBum]

Interesting...
http://cgi.ebay.com/ebaymotors/ws/eBayI ... 0737507310

First I've heard of them. Variable rate springs. 221 lbs. 492 lbs load? Wonder if that's 221 to 492 lbs. Much stiffer than stock. Wonder if they sell matching front springs.

[BadQ45t]

The rear dropping down like that is something that the car did on day one, trust me I had a 84' and one writer commented that it feels like you dropped an elephant into the back when you jam on the gas. I fixed mine by replacing both shocks and struts. I used KYB's and Eibach springs that lower the car about 1.5". This pretty much solved the issue once and for all. I would suggest you see if you can find a set of the Eibachs lying around if you want to lower the car and the SS springs if you want stock height. Also, Bilstein makes shocks/struts for the old Z's now and they are very stiff, so you should know that in advance. The issue with an older car and very stiff shocks is you can expect some extra "noises" in the way of rattles etc. If those don't bother you go for it. Also Tokiko makes the adjustables still for the Turbo model.

As a previous post pointed out, the Z Turbo came with adjustable shocks, all of which no longer work. So most people eliminated the feature with stiffer springs and better/stiffer shocks.

[Nissan for fun and work]

Thanks for the help, I'm going to try out the Rear Moog Springs. I ordered them and have them at the house now. Just waiting on the Rear Shocks to arrive so I can install them both at the same time. Hopefully I will have this done this weekend and this time next week and can post the results. I'm ready to drive it...

[Nissan for fun and work]

Ok, I managed to remove the coil springs however i'm having a hard time removing the lower bolts that secures the shock. Any suggestions?

Also, i noticed that the lower coil spring rubber insulator / seat, is cracked and needs to be replaced. What will happen if i don't replace it right away?

Nissan for fun and work

[Nissan for fun and work]

Okay, I have removed shocks and springs.

Now I have another concern which is when i drive the car it makes a loud "bang" sound as i'm switching gears. Anyone knows what that could be?

Nissan for fun and work

[AZ-ZBum]

http://z31.com/phpBB3/viewtopic.php?f=24&t=4777

[Nissan for fun and work]

I've been off the site for a little while. Still working on the car. Still have the knocking noise when I drive. When I hit the accelerator pedal, I hear the knocking noise. I changed the rear shocks, springs, CV axle and still have this noise. Anyone have any more ideas?

Nissan for fun and work

[Nissan for fun and work]

Sorry, az-zbum gave a site to look at. I reviewed it and will be checking the mounts and rubber bushings...

[evildky]

drive shaft U joints, crossmember bushings, trailing arm bushings, lost of ear items back there

[dem00n]

Sorry for the necro bump.

I'm curious if OP ever figured out what was causing his that bump every time you touched the throttle, I'm having the same problem as well. I'm guessing it to be the u joints on the drive shaft.

Thanks...

[Desert Rat]

More likely the diff insulator - basically a rubber pad on top of the diff.

[dem00n]

More likely the diff insulator - basically a rubber pad on top of the diff.

Hello,

Just curious, do you mean #55476? The INSULATOR-DIFFERENTIAL MOUNTING they call it?


I was going to check this week if it was possibly the U joint on the driveshaft since it feels like a bad u joint.

How would one check for a bad diff insulator? I'm guessing by going to the area and prying to check for movement?

I'm hoping it's not the diff insulator, because that's $140, it be the most expensive part on the car so far, even with $1700 invested so far!

Thanks, i really appreciate it.

[evildky]

The diff mount isnt a common problem. the crossmember bushings (PN 55466) are a common issue but not likely to cause the issue you describe. For the issue to be on throttle the U joints or trans mount are more likely but ultimately you need to get under there and start inspecting parts.