BuckeyeBoys

So our new to us 05 Roadster with 73k miles needs work. I drove with the top up one cold morning and heard the whine of a bearing. Sounded like left rear and would change with speed and putting car in neutral made no difference in sound. You really can't hear it with the top down!
I lifted it and got under it today. The left rear does have a small amount of looseness when moving the rim. All the other wheels checked good and tight. I did notice some oil staining on the inner CV axle hub, so I'd like to know about that as well? Do these leak?
I see plenty of YouTuber videos changing the rear wheel bearing, if you folks have a favorite Z guy on youtube please let me know. My question is about the cv axle also, plus I heard you can upgrade to the 370Z axles and wheel bearings? IF that is true I'd like to know what parts to get. I have pictures that show the difference in the right dry/rust covered hub and the left/driver side oily hub.
Pictures show the oil covered and the dry/rusty axle. Also my W brace is rusting away, don't see a need for an aluminum brace on this car, supposedly this is a almost new Nismo exhaust also? removed from another car. At least my differential bearing is not leaking. When i replace the wheel bearing this winter I will probably change the shocks and w brace. Good place to look for the W brace? I was looking at the Bilstein shock replacements but I'd really prefer a smoother ride for this car and I heard they are way stiffer than factory shocks. Thanks for any help





axle

icer5160

iTrader: (4)

Hey Buck,

I just went through this process on my Z. You can read up on the details in THIS thread. But to summarize...

1) I went with OEM 370Z rear axles that I found on Ebay, the 1st set was super clean (as seen on Ebay listing) but one unit apparently was damaged in shipping, so I grabbed an alternate set from a more local auto dismantler and returned the damaged set. I felt kind of bad for the seller, but that's why you use proper protection for heavy items when shipping cross-country!
2) I went with OEM Nissan wheel bearings that I purchased through Z1. I don't trust the NVA (Nissan Value Advantage) parts, they are much cheaper for a reason. I also don't trust the aftermarket options. A brand new Genuine Nissan 370Z axle costs over 1k each and should last the lifetime of the vehicle assuming boots are properly maintained and greased.
3) I used the Z1 hardware kit simply because it was easy, and I'm sure much cheaper, once you piece a kit together yourself directly from Nissan. The quality of the Z1 hardware kit is good.
4) If you go the 370Z upgrade route, make sure you follow the 370Z axle nut torque specs, use 350Z specs for everything else.

Ok, now into the finer details...

If you do your homework on 370Z axles, you will discover that depending on the year and AT vs. 6MT, the axle flange design changes. Some have threaded flange holes while others require a bolt + nut to capture the flange to the diff (same as 350Z). The 370Z axle flanges are also thicker, about 1/8" of an inch. You can re-use the original 350Z nuts and bolts, but you would have to drop the lock washer to accommodate the thicker flange. I didn't like this, so just another reason I went with the Z1 hardware kit. To ensure a proper fitment and lower mileage, I searched for 2016+ 370Z axles from a 6MT.

The 370Z bearings are a direct replacement (same x/y/z perimeter dimensions), no modifications required to the rear knuckle. The splines are simply larger to accommodate the beefier 370Z axles, hence the upgrade needs to be done as a set. But it's clear that the 370Z bearings are nearly or about twice the strength vs. the 350Z design. I suspect the 350Zs bearings are a single set/row of ball bearings, while the 370Z is doubled up. That or there's a bending moment issue (load not evenly dispersed).

Now to answer your other questions. Just purchase a new OEM W-Brace. You can get these from many parts sellers, including Z1 or direct from Nissan. As far as the oil residue, this is normal. The end caps on the axle can start to seep as they age, I suspect the CVA grease inside starts to break down. It's not something I would be super worried about unless it was slinging oil/grease around your undercarriage. I'm guessing the rust might be opening up the gap between the flanges and allowing some seepage out. When I installed my new axles, I put a very thin layer of grease on the mating surfaces to help prevent surface rust from forming.

In terms of the exhaust system, I can't comment based on 1st hand experience. If it was a Genuine Nismo system, it would say Nismo on the muffler(s) or rear tips. Based solely on my memory of seeing pictures of them for sale over the years.

In terms of the suspension. I'm running with Bilstein B6s and I'm happy with them. They are a bit more aggressive vs. the OEM units, but I also upgraded my coil springs to the OEM Nismo units (off an 08 Nismo). I think the coils have more to do with the ride quality in my case vs. the Bilsteins. If comfort is your goal, then this is one area where I would recommend going with the OEM shocks/struts. They shouldn't cost any more than buying a set of Bilsteins. If you're only targeting the rears, then I recommend the KYB upper bushing kit. I would also pick up a sheet of silicone gasket (1mm thick) and make new gaskets for the upper shock hat where there's metal on metal contact. Doing this helps eliminate squeaks/creaks/thunks when working the suspension hard on driveways and such. The OEM gaskets all flake apart over time, they were never made of sturdy material.

There's a ton of Youtubers covering 350Z stuff. You're right to be wary about who you take advice from. I think AnthonyJ350 does a decent job covering a lot of stuff. Other channels I respect are "Full Throttle" and "Z-speed." Otherwise, it's mostly hit and miss, weekend warriors just covering one small aspect of Z maintenance & repair.

Hope this helps!
Cheers!
-Icer

icer5160

iTrader: (4)

Also, it looks like it's really time for some new Differential Bushings. I can't even see the capture nut through all the rust! Amazingly, the rubber doesn't look ripped or cracked through yet.
Cheers!
-Icer

BuckeyeBoys

Great reply, thanks! Your recommendation of axles, (06 6sp manual) will those work ok since my car is an Automatic?
Also is 73k miles a normal time to wear out a rear wheel bearing? Just curious. I'm sure the shocks need replaced but the springs also?
Thanks for the detailed help!