DarkZ03

iTrader: (11)

I've bought my Nismo bushings from Nengun or RHDJapan. I'm pretty sure Nengun has them on sale right now, I just bought a pair and even after shipping it was still about $20-30 cheaper than US vendors.

icer5160

iTrader: (4)

You wouldn't happen to have a parts list for those Nismo bushings would you Dark?
Cheers!
-Icer

DarkZ03

iTrader: (11)

I do not, what I did was I got the numbers off of Z1 website IIRC

icer5160

iTrader: (4)

I found all the Nismo rear knuckle and control arm bushings....except for the rear shock fork bushing. I'm guessing a Nismo version does not exist or the same Nismo P/N is used elsewhere on the knuckle and it's just not documented. I can easily find the OEM bushing though, but I think poly might be better for the lower shock fork. It's holding up great so far for my front lower strut fork. Honestly I'm a bit torn on which to go with (OEM vs. Poly).
Cheers!
-Icer

DarkZ03

iTrader: (11)

Personally I don't like the idea of polyurethane for lower shock mounts, there is a little articulation that the polyurethane won't have, I currently have Whiteline there but they will be swapped out for SPL eventually. IMHO, SPL or OEM for the lower shock mounts.
Before it comes up they add precision and no NVH, just ask OP.

VQplatform

Personally I’d either go between oem/Nismo or SPL. Poly can end up squeaking at times. I’m only running SPL FUCA,Rear Camber
, and Traction Arms. Z1 Front compression monoballs and the rest is either oem or nismo. NVH has not been an issue for me. I would want to try SPL for the inner front lower arms and for the rear inner spring bucket bushings. Yes all bushings on the rear spindle except for two, Nismo did not manufacture.

icer5160

iTrader: (4)

Ok, update on my rear end noise situation.

Yesterday, I got the car up in the air and did a full rear end suspension check. None of the OEM bushings appear to be broken or severely damaged. I did notice the low half of the strut fork bushing has a crack starting, but doesn't appear to go all the way through the bushing collar. For now it's superficial. All the other bushings at both the arms and spindle/knuckle are in good shape. Zero play in the suspension components.

Now what I did discover is a bit concerning. I'm getting some slight axial play in the driver's side axle, meaning if I tug the axle shaft inward (towards diff) and outward (towards spindle), I'm getting some play in the form of a popping sound at the outer joint. If I rotate either axle, there's zero play or slop. I did the classic wheel tug check for bearing play. Everything feels solid there. The driveshaft also feels solid, zero slop/play both axial and rotation.

To further investigate, I had the vehicle idling in 2nd gear to get some final drive rotation so I could listen with my stethoscope. The differential sounds smooth and quiet, zero bearing noise coming from there. But I'm getting some subtle crunchies from the passenger side bearing. It's hard to tell exactly because I think the e-brake shoes or brake pads (Brembo calipers) are ever so slightly dragging on the rotor. If they are dragging, it's not for the full 360 rotation. Not the perfect testing controls I know and if I wasn't pressed for time, I would have removed the wheels and brakes and listened again with my stethoscope.

Here's where I'm at now. The axial play or popping sound I'm getting from the driver's side axle is concerning me. What's more, I noticed both axles are not rotating true. There's about ~1-2mm of runout or wobble in both axles (center section). Perhaps this runout is related to the suspension being in the relaxed position? Perhaps I'm not getting the full picture of the bearing noise because there's no load/weight applied to it. I don't know, but I think there's enough evidence here to warrant replacing both rear wheel bearings and axles. I plan to go with the 370Z axles and bearings. OEM bearings aren't that expensive, but axles are. So I'll see if I can find a used low mileage set. I've seen some negative feedback about the NVA axles and I don't know if I can trust the Z1 Hayaku axles. Also, I'm aware that the 370Z axle flange design changed over the years. It's a shame to replace my axles after spending a lot of time de-rusting and painting them. I haven't put much use on them since then. But I feel like I can't trust them now.

I'm open to suggestions regarding the axles. Does anyone have any feedback regarding aftermarket axles? Much of the feedback on these Hayaku axles from Z1 is good, but those reviews are based on less than a year or two of use. What I want to know is if they can hold up for 10 or 15 years with 150k mi on them (wishful thinking I know).

Cheers!
-Icer

VQplatform

Nice work in taking a methodical approach. I would either recommend finding low mile possibly “JDM” axles and rebuilding or going with new OEM axles because aftermarket won’t cut it. I’d rather pay for something I know was built with much higher quality even if used. As far as the noises, I would recommend taking the axles apart for further inspection. The crunchy noises doesn’t sound like it would be your parking brake because that would give more of a dragging/rotating/sandpaper sound. The crunchy sounds might be more probably to be your bearing but interesting that there was no play when checking the wheels. I would probably try to asses the parking brake again, put it up on stands pop it in neutral, take the wheel from that side off and rotate it by hand and then remove the caliper to see if the rotor is hard to get off ( with the handbrake off)

icer5160

iTrader: (4)

Found a set of used Z34 axles on Fleabay! Came off a 2019 370Z involved in a front end collision, only 19k mi on them. Fingers crossed nothing wrong with them (For the price, it's worth the gamble), also ordered OEM wheel bearings and all needed axle hardware.

The used axles suffer from the same surface rust that all OEM axles have. I'll be cleaning them up and giving them the same treatment I gave my old axles.

Hoping to get them installed in two weeks, got other family mechanic car projects I need to work on this coming weekend.
Cheers!
-Icer

icer5160

iTrader: (4)

I forgot to mention in my earlier troubleshooting post, that I did remove the Gktech diff brace (only takes a few min) after checking things over underneath. I took the car out for a test drive to see if removal of the brace would make a noticeable difference. It did not, the growl or whirring noise I'm hearing is still present. More evidence pointing to something wrong with the bearings or axles.
Cheers!
-Icer

icer5160

iTrader: (4)

Update: Axles, bearings, and hardware arrived yesterday. I can't wait to get started on this (hoping to begin this coming weekend) as my job keeps me away from home during weekdays.

Last weekend I knocked out major suspension and brake work on my daughters 06 Civic (and a valve adjustment!). I replaced all 4 wheel bearings, front control arms, sway bar bushings + endlinks, and installed new rotors + pads all around (Centric Painted Rotors + Akebono Premium Ceramic pads). The car has 198k mi on it and runs great. After the control arm replacement up front, the alignment was severely out of spec (front toe in particular). I had the alignment done and got it smogged (passed without issue). I still need to replace the tires, but otherwise that Civic is an excellent daily driver now. It's come a long way since purchasing back in June 2022.

Then I helped my nephew with his 08 Civic, both cars have the same drivetrain (Honda R18, 5AT). The 08 Civic needed a new serpentine belt + tensioner, VTEC solenoid gasket had turned into plastic and was leaking oil like crazy (very common on Hondas), so that got replaced. I also serviced the transmission and made other repair recommendations before calling it quits. Other items that need addressing on the 08 Civic include new shocks/struts, potential rebuild on PS pump, replace missing center splash shield, throttle body clean followed up with a TPS relearn and Idle Air Volume relearn, and replace lower radiator hose with OEM. The hose installed right now is a Gates unit, which in my recent experience have turned out to be crap. They develop slow leaks and I confirmed as much with the hose on this car.

Getting both cars done in one weekend was rough, but I wanted to get those commitments out of the way to make time for my Z this coming weekend. I'll be sure to post updates.
Cheer!
-Icer

icer5160

iTrader: (4)

Update: I unboxed the axles from Fleabay Friday night only to discover one of them (the shorter one) was severely damaged. The Inner CV was completely locked up. I thought "no big deal, sometimes axles pop out of place when improperly handled and I just need to get popped back in." Boy was I wrong, the inner flange grease cover was smashed beyond recognition. It looks like this axle took a serious hit that I find hard to believe happened in transit. Although the packaging was not the best, the bubble wrap job should have been adequate to protect the axles from light to moderate rough handling. The damage I discovered looked like the axle was dropped off a 3 story building, smashing the inner CV bearing set perfectly into the maintenance/grease cover. The outer CV on the same axle appeared unscathed. It's very odd to say the least


How they looked on Ebay. Notice the flat grease covers.

Ebay listing, just different angle.

Damage to the shorter axle.

Damaged axle, different angle.

Needless to say, I was seriously disappointed. I waited nearly two weeks to get my hands on these and I planned my weekend to work on this project. It's a real bummer and shame. These axles were in excellent condition (initially) and the shorter one was destroyed either in transit or by the seller during packaging. The good news is that the seller agreed to accept the return based on the damage.

Not all is lost though! I wasn't going to let my 370Z axle upgrade and weekend plans get delayed further. I was able to find another set of low mileage axles from a semi-local Auto Recycler/Dismantler in Rancho Cordova, CA (Near Sacramento). These axles were advertised as coming off a 2016 Z34 6MT with 37k mi. Not bad in terms of age/mileage, but not nearly as perfect as the 1st set (prior to the damage of course).

I drove the 1.5hrs (3hrs round trip) to pick up the axles directly from the 2nd Fleabay seller Saturday afternoon. After getting them home and starting the cleanup process (preparing for paint), I noticed that one of the axle threaded shafts was dinged up pretty good (also the shorter axle!). I was in such a hurry, I didn't closely examine the nose of the axle (lesson learned!). I tested one of the axle nuts that came with the damaged ebay purchase and discovered the threads were indeed damaged. The axle nut would not thread on without serious force (impact gun). Talk about bad luck!


It looks beat to hell from a mini-sledge. Note: Photo taken after re-threading.

Same axle, different angle. Notice the taper on the right side. Note: Photo taken after re-threading.

I wasn't going to let this stop me though. I ran over to Harbor Freight and picked up their Titanium Tap and Die set. This set has an M24-1.5 die. Luckily, there's a Harbor freight less than 5 mins drive from the house. I've been meaning to purchase this exact set for a while based on independent reviews. It's one of those not so well known gems from HF. For $100 (including tax), it's an amazing set. I was able to quickly re-cut and clean up the threads on the damaged axle. The OEM nut threads on like butter now.


Amazing set for the money!

After all that running around, I was able to focus the rest of my time on cleaning off all the rusty crusties and prep both axles for paint. Clean up took the rest of Sat night and most of Sunday morning. By late Sunday afternoon, I had both axles painted and hanging to cure in my garage. I really love the new 5 in 1 rattle cans from Rustoleum, these things are SOOOO much better to use! I cannot recommend them enough. I hit both axles with Rust Converter (two coats) followed with Satin Black (three coats). Aside from a few specs of dust that landed in the paint, they turned out great, I'm very happy with the end results. You can actually see/read the markings in the cast pieces now.


Where I finished up Saturday Night.

Longer axle, inner CV.

Longer axle, outer CV.

Shorter Axle, inner CV.

Shorter axle, outer CV.

Both axles hanging to dry.

Next weekend I plan to get these babies installed with the new OEM Z34 wheel bearings.
Cheers!
-Icer

icer5160

iTrader: (4)

Update: New axles and bearings installed. The installation went smoothly, no issues. After taking apart the right rear brakes and removing the axle, it was very clear/apparent that the bearing was in the intermediate stages of failure. Although I couldn't detect any play/wobble with the bearing yet, when spinning by hand without the drag offered from the final drive, there are multiple rough patches. So it looks like my ears weren't lying to me when I listened with the stethoscope, it was just difficult to be sure because the noise wasn't audible at low RPM without any weight on it.

While I was under the car, I decided now would be a good time to service the differential fluid. Oddly, OS Giken doesn't have maintenance intervals posted on their support page for their differentials. I ended up emailing them directly and was told every 3 years at a minimum. They didn't give me a mileage number, but I'm guessing 3 years equates to roughly 30k-40k mi, possibly less depending on the vehicle use (heavy track or street). Also, confirming the bearing issue and the fact that no change was witnessed when removed, I reinstalled the Gktech diff brace.

After the work was complete and car back on the ground. I took it out for a shake down spin. I'm happy to report everything is quiet and smooth. Absolutely no rear end howling/growling. Whether at freeway speeds or rough/bumpy roads, everything feels as it should. Definitely an upgrade worth doing if you can source some quality axles. Going with used OEM proved to be the trickiest part, but I think worth it in the end.
Enjoy the pics! Cheers!
-Icer


All the parts/consumables. The axle hardware kits are from Z1.

Where's the beef!? The 370Z bearing is a chunker!

Passenger side axle in, feels nice getting those rusty hubs replaced.

Inner CVs mounted up without issue to the diff.

Looks clean!

The outer CVs for the 370Z axles are noticeable smaller in diameter, which makes future maintenance much easier!

Old hardware out, new hardware in, Z ready to go!

MelissaPeterss

I was going to do the Whiteline subframe bushings but ended up just going with the Z1 collars, they are almost as effective and SO much easier to do. I have the Whiteline bushings I never used that I could probably cut you a deal on.

MelissaPeterss

I was going to do the Whiteline subframe bushings but ended up just going with the Z1 collars, they are almost as effective and SO much easier to do. I have the Whiteline bushings I never used that I could probably cut you a deal on.