Treacy

I have an 86 N/A and the bushing on the top right rear shock has worn off. Now when I drive over a speed bump or over a bumpy road there is an aweful rattling noise. I want to know what bushing that is? I found some red prothane ones from Andy's Auto Sport.comhttp://www.andysautosport.com/nissan/1984_1989_300zx/suspension/bushings/shock_bushings/prothane/
The "nipple type" stabilizer bushing is the closest match. Is it the right type?

Shocks:
I did the whole "push down shock test" and the shocks seemed ok, but sometimes all it takes is a raise man-hole cover or a bad asphalt patch job on a tight turn to compress my shocks and make a loud bang noise. The right rear shock also makes a "squoosh" noise over speed bumps too. So should I replace my shocks? I put a lot of highway miles on my z so I don't want shocks that are really stiff. I'm also from PA "home of the worse roads". Would the Tokico Blue Shocks work for me? Do they need to be modified to fit my z?

Any help would be appreciated!

ken99

Prothane urethane bushings can be ordered directly from the company, usually at the best price and the kits come with the proper lube. Goto Prothane Suspension Parts: Nissan 300ZX 1986.

Check the right rear shock mounting plate by removing the rear speaker cover and then unscrew and remove the speaker. Underneath is the top of the shock. Have someone reach under the fender opening and giggle the shock. Either the shock is loose in the mounting plate or the entire mounting plate (secured with 3 bolts) is loose. It may be the entire plate is loose and simply needs to be tightened back up. Otherwise, I would remove the shock and figure out what is wrong.

Shock brand? This question is sort of like asking which brand of oil filter is best, everyone has an opinion (NO, please do not go there.). Koni and Bilstein are general regarded the best. If you price a single Koni shock, you will discover you can replace all shocks and struts on the car with something else for the same cost. Unless you plan on racing the car, these two brands are overkill (IMO). Tokico and KYB are good intermediate price choices. I've replaced my rear shocks on my 86 NA with KYB and really like the handling improvement, but I have to admit the previous owner had some POS Monroes installed. I've read on one of these forums KYB are good in the rear with Tokico up front. I'm considering this approach since this winter's projects are mostly suspension work. Since Tokico was the OEM supplier for NIssan when the car was built, I am sure they still make a shock that fits the Z31.

Treacy

Thanks Ken99 for the response.

Yes, I really want to go the red polyurethane bushing route. I have the bushing that wore off so I'll match it up with something that Prothane has.

Without the rubber bushing the shock does sound and even looked loose when I inspected it.

That's actually what a lot of people said about the different shock brands. I was already partial to tokico since quite a few of the z31 domains used them. Do you remeber what the guy's reasons for having KYB in the rear and Tokico in the back? That sounds like a great option because I think the KYB are cheaper than the Tokico. Half one brand and half the other would make it a less expensive project. What brand of bump stops did you use or do Tokico and KYB shocks come with them? I hear KYB bump stops are crap.

FlyingT

The banging you hear may be that bushing or others that have worn out. If one has worn out (like the right rear) all of them are probably close behind and need to be replaced. MSA (theZstore.com) has an entire complete set for the Z31, except the rear crossmember bushings that don't come in the kit. Get that busing too. While you are at it, look at the tranny mounts, and rear diff mount. Those wear out too.

ken99

I guess the KYB shocks are a stiffer setup than the Tokico, and the reverse is true with the front struts. The mixed setup was consdiered a better match for an overall tighter suspension.

I bought the KYB bump stops and I would have to agree. But they also serve as a dust/mud shield and I drive on gravel roads so often, so I installed them anyway. IMO, they really are not needed if you drive on descent roads.

Treacy

Reply to FlyingT:
Yes the right rear bushing is worn out. It was actually sitting on on top of the shock, hanging on by a thread of rubber. The sway bar bushings are cracked an nasty looking too. I'm at college and on a limited budget so it slow going replacing what it worn. Are those prothane bushings I sighted in the link above the right fit for the top of my shocks?

Reply to ken99:
Ok, I'll have to give it a try. That's good, because the Prothane bump stops didn't look like they would work on my z and they would be the ones I'd use.

Thanks guys for the replies!

Treacy

I replaced the right rear shock bushing. No more metal on metal thump noise. Still waiting to do the rest of the suspension work.

ohsemix

now that we are talking about prothane bushings is it safe to have them on the all the suspension or is there places were rubber once are needed. Im asking because i have heard of this in a thread on hybridz were if you put it on a sirtain part it snaps but i forgot which one.

Treacy

I have yet to find someone who did not like or had problems with Prothane poly. bushings.

Treacy

I finally got around to working on my suspension. I talked to some guys at a suspension shop and they said my problem was my springs. I went ahead and order a complete set of Eibach Pro Kit springs and installed them. What an improvment in the ride quality. It is night and day. I did find out though that the front shocks were completely gone. Unfortunately my z is my daily driving car so I had to put everything back together with bad shocks. I actually had to hold up the front shock pistons in order to put the insulator nut on. I also had a guy, Gary Molitor, make custom polyurethane spring seats for the front and the rear. Total cost for those plus shipping was $95. I'm waiting to install the spring seats and new front shocks.

FYI not sure if this is true for everyone but when I tried ordering Tokico Blue Shocks the sales women told me that Tokico went out of business and you can no longer get them (at least from the supplier I tried by from). Pretty much set on getting Bilstein Shocks though.

FlyingT

Tokico still has a web site. There is no info on the web that they are OOB. I bet they are still in business. Try another supplier

Treacy

I tried Motor Sport Auto/ Z store and their Tokico shocks are on back order. Appearently, all Tokico shocks (at least for the z31) are on a national backorder for several months.

Treacy

Update:

So I have finally installed Bilstein HD shocks and Polyurethane spring seats. I also install new KYB upper shock mounts. The ride quality of my z is night and day. I can take turns fast without bottoming out. Pot holes, train tracks, and road patches are no longer a pain to drive over. FYI if you want to unscrew the glad nut on the strut housing, do it while it is still mounted in the car. It is so much easier. Also the Bilstein shocks come with two new glad nuts. One with more threading and one with less. The one with less is the one I used. FYI #2 a 1/2 impact gun is a must! A 3/8 won't do it.

All I can say is I am very happy! I look forward to upgrading the sway bars and doing some more suspension improvements.

Thank you all for your help!