Diff Bushing upgrade
 

How many here have gone with urethane diff bushings? What were your experiences? Did you experience more vibration as a result? What performance benefits did you experience?

Looking at this set: https://www.z1motorsports.com/z1-pro...t-p-10356.html

Don’t.

I’ve done solid bushes with rose jointed suspension on an S13. The noise is horrendous. It handles well, but it is awful noise


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Which type did you run? The ones I linked are urethane, any experience with those?

Hard race


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Lots of people here have gone with the Z1 urethane diff bushings and reported no big increase in NVH.

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:shakes head: Go to your favorite web search and type in "urethane bushing site:the370z.com" (site:the370z.com limits the search to this site). Add -christ to omit hits on a sig that has urethane in it.

Indeed if you search you will find a lot of info on this topic. Depends on what your tolerance to noise is? What do you use your Z for? If your Z is mainly for street duty I recommend the urethane differential bushings as excessive noise from solid differential bushings used for street duty can be annoying to some. If you track your Z at all definitely solid differential bushings would be the choice. I recommend the Whiteline urethane differential bushings I found them to be quite durable in my experience. If you install differential bushings don’t forget to get the rear differential bushing removal tool you will need it. Also this is a great time to change your differential fluid.

Thanks! I don't track the vehicle, it is my daily at the moment and my driving is spirited whenever I have the opportunity. I most likely won't be doing the install myself. Should I expect vibration with the urethane bushings also? In what form would vibration manifest itself with them? Cabin noise? Vibration felt in the shifter or other controls?

I've had the Whiteline poly diff bushing installed for the last 80K miles. There's still some slop back there but no issues on the street. SPL solid bushings are sitting in the garage awaiting install for track mode.

White line was mine. I did the anti roll bars as well. Diff noise was terrible but fun also. Don’t go for rose joints


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If you can’t or don’t have the means of doing the rear differential bushing install yourself take your Z to a shop or Nissan dealership service department you trust to do the install for you. This is an ideal job for a transmission/driveline shop. Depends on if you are on stock suspension or not will also depend on what noises you will hear from your suspension as well. Also consider the streets/highways you are driving on as well. Most of all brand polyurethane differential bushings for our Z’s have the same characteristics and noise level as the Genuine Nissan OEM rubber bushings don’t be afraid to install them and polyurethane bushings are also more durable than rubber bushings in turn they will last a lot longer. Performance wise it will improve with the polyurethane differential bushings but you will still have some play in the rear. I have been running solid differential bushings on every Z I have had only really notested noise with the solid differential bushings the polyurethane differential bushings are overall quiet.

Do the install yourself. If you're not mechanically inclined that's okay. You'll gain lots of new tools and knowledge out of the experience.

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I actually am mechanically inclined. Have a bad back and neck, so I choose my battles these days lol :icon17:

You need an Acetylene torch to cut the old
Bushes out. If you like refinement don’t do the Diff bushes. If you like the whine of a Hewland race box do it, because it grinds and whines like a rally car . I regret going solid bushes for a daily driver


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I have the Z1 poly bushings and like them. No gear whine at all. My subframe however has solid NISMO bushings. I also have a modified Bellworks diff brace. I did get some noise from that.

Was it that good?
I was talking just about solid sub frame bushes. I had rose jointed suspension. Handled like it was a Kart, but the noise, was tough but loved it


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What are you trying to do with the torch? Burn the car down? :eek: A 2" diameter deep hole saw will cut the old bushing out. Then use a sawzall to cut the outer shell in 2 places. Then knock it out with a muffler tool. Takes me about 3 minutes to remove the old bushing. I've done 3 bushings for other people so far.

I have the SPL solid diff bushing, the Bell diff brace and the SPL sub-frame bushings. I did the diff bushing first. Really, it wasn't that noisy. Even with the solid diff bushing, diff brace, and solid sub-frame bushings. It's not that noticeable.

Every suspension bushing on my Z has been replaced with SPL spherical bearings. There is NO rubber in the suspension. :driving:

No I took the subframe off first


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Here's all of my install threads for the suspension. :tup:

http://www.the370z.com/brakes-suspen...uspension.html

http://www.the370z.com/brakes-suspen...on-almost.html

http://www.the370z.com/brakes-suspen...e-install.html

http://www.the370z.com/brakes-suspen...ml#post3825514

Here was my S13 subframe. Solid bushes, poly bushes and Rose jointed suspension

It was noisy as hell but handled like a go kart

https://uploads.tapatalk-cdn.com/201...36617c9f29.jpg


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The only downside to it is going on and off throttle in traffic. 10mph There is no play so it is not very forgiving. It will buck some if you get the throttle and clutch input wrong. Been stuck in traffic many times.

I replaced my rear diff bushing since, as expected, the fluid-filled OEM bushing started leaking. My Z is stock (total DD), so I didn't have any noticeable increase is noise or vibration. The rear feels slightly more "planted" during take off and gear shifts, but it's very subtle.

If you have a transmission jack, it makes the replacement much easier. A multi-oscillating tool and sawzall is all that's needed to replace the original bushing. I went with Z1 in front, and Nolathane for the rear - and changed out the diff fluid in the process.

Have you replaced them out yet?

I did poly subframe, diff bushing, Z1 Diff cover, bell raceworks diff brace, and poly trans mount when my diff bushing blew out half a year ago and I just installed all the rear SPL knuckle bushings and replaced all my suspension arms to voodoo13 and SPL endlinks.


It's so much easier drop the entire subframe and work on it on a table

You got the Bell diff brace. What exhaust you have? How much clearance between the exhaust and brace?

I have berk exhaust and no clearance issues. I saw your post with the FI clearance issues.

Z1 solid front? What's Nolathane?

If your funds and/or S/O allows for it I would upgrade the subframe bushings while you are in there. The difference is night and day :excited:

Australian brand like whiteline, but cheaper

So the Diff Brace clears with no issues with the Berk CBE? Any modifications needed for install? Was looking at getting this but read somewhere that it won’t clear the OEM or similar type of exhaust systems and it had only been proven to clear with the single exit Tomei

Any exhaust that tucks up tight with the diff will have clearance issues.

Yup no issues, no modifications. I wasn't really planning on doing anything on the rear since it's a daily driver, but the diff bushing blew and then i accidentally blew a bunch of money to upgrade all the rear bushings. The rear subframe is really easy to drop.

As mentioned; the Nolathane bushings appear to be identical twins to the Whitelines. I installed the Z1 polys in front (DD, not a track car).