75k Miles - Time for Suspension Rebuild - Help!
 

My 2009 Sport 370's suspension is dead stock. It's a daily driver so I'm pretty happy with the suspension as is but I'm definitely noticing that some stuff is worn/wearing out. Biggest issue besides a little looseness is tramlining. It's getting downright scary under braking.

I'd like to do the rebuild in two major phases, first, all the bushings/wear parts and second the springs/shocks. I'd really like some advice on stage one right now. Since I'm not loaded right now I need to go at it slowly. In about five months it will be a second car so I'm perfectly fine going for performance over comfort.

Questions:

Is there a particular part of the suspension that is the major contributor to tramlining as it wears?
What parts should I be replacing in order to return the suspension to its original glory?
Are there parts that wear really quickly as opposed to others or do the suspension wear components mostly go downhill together?
Are there any parts that should be uprated as opposed to going OEM? I don't care about NVH unless it's brutal.

I'd like any technical details you've got as I'd like to understand what parts wear, why they wear and what affects they have as they wear. I'd love to come out of this knowing what a particular issue (like tramlining) comes from so I can know the cause and not just throw parts at it.

Thanks in advance for the advice and feedback.

Tramlining comes form having wide tires
Can be aggrivated by poor alignment
I think spacers will make it worse
Check ball joints and wheel bearings first.
Try to stay out of grooves in the street. Brake on the flat areas,not on angled surfaces.
Do everything at once so you don't need to do multiple wheel alignments

The FLCA (Front Lower Control Arm) bushings can cause tramlining. I had a noticeable decrease when I went to a set of SPL front bushings on the FLCA's. I have yet to do the Impact Bushings however.

If the Z will be a second car soon, I HIGHLY recommend going with everything SPL. My Z is my daily and I will eventually have just about everything in the SPL catalog on my Z.

Spacers don't make the problem worse really from what I have noticed on my car. The stock bushings causing dynamic alignment changes will do the most to cause movement under braking.

Multiple alignments aren't a big deal if you have a trustworthy Firestone shop around you for a lifetime alignment.

Recent alignment helped maybe 20%. Tires in the last part of their lives is probably about a third of the issue now. Those are coming soon.

Hadn't thought about wheel bearings. I'll check them out.

Are ball joints something that can reliably checked for play on our cars or are they just usually just replaced based on mileage/abuse levels?

I have a lifetime alignment already! Plan on using that a lot 😁

I've been suspecting the FLCA bushings. I imagine visual inspection won't tel you much unless they're really gone. What are the impact bushings - never heard of that before? On the FCLA's I've heard great things about delrin but can't find any suppliers. Are they only available as a custom machined part? And what's the material used on SPL's stuff?

My spacers made a small difference when I put them on but seemed very minor.

Check on the lifetime alignment. Very good investment.

The visual inspection won't do much unless they are severely worn out.

The impact bushing is the big round bushing on the rear mounting point of the FLCA.

I can't think of anyone off the top of my head that makes off the shelf Delrin stuff that you can just order. It would have to be custom made. Which isn't a big deal if you have a spare set of every bushinh you want to replace.

SPL is solid aluminum, spherical bearings, or heim joints. No rubber or delrin at all in any of their products for the 370. Here are their offerings for the 370Z. I have their solid diff bushing kit, and the front bushings for the FLCA's.

Nissan - 09+ 370Z (Z34) - SPLParts

One thing that can be a good sign of failing bushings on the front is if you have inside and outside edge wear on the tires. When mine were getting really bad, I would be killing the inner and outer tread on any tire I had because of the dynamic toe change the bushings were causing. That wear characteristic has been very minimal since I changed the one set of bushings out.

I have noticed increased inner and outer shoulder wear recently. It matches my impression of the slow increase in tramlining.

What kind of increase in noise/vibration did you see with the SPL FLCA bushings? Any downsides to them?

Any thoughts on the affect of upper control arm bushing? Do they just not wear as quickly? And how about the rear? Same thing?

Wheel bearings on all four corners are a relatively easy thing to fix. They come as assemblies, so it's 4 bolts on each (depending on front or rear) to remove them from the spindles and replace them. Amazon has the Beck-Arnley parts for the front @ $96 each and Timken for the rear @ $54 each. GL

city vs hwy driving must kill the suspension a lot quicker...I had 250,000 miles and no real suspension problems...
I would go for an alignment first and go from there, other than wanting to do some upgrades that might be all you need.

Did you have the OE (from factory) springs, shocks, struts with 250k on them?

I sure did.
Replaced the front hubs at about 150k...something like that. I have a thread I started with problems after 200k. Other than CSC there wasn't a lot really.

You can get tram lining with any tire big or small. Alignment and suspension slop is the only culprit.

Larger tires and stretched tires are just prone to substantially higher levels of uneven wear, which will make tram lining much more apparent.