Z1 rear differential and subframe bushings
 

I ordered these a while ago and installed the front two bushings easily and then realized how much more effort was required to install the rear subframe bushing. So just this weekend I finally had time to install the rear subframe bushing.

I really wish the guys at Z1 would have given me some indication that the rear subframe bushing requires a lot more time and effort than you would expect as it will require a lot more planning than you would think. The problem is there is no good way to get the proper tools on the bushing to get it out. Most people cut open the bushing, drain it, and saw out the outer race.

We cut open the bushing, but then got creative. My technician decided to use a torch to melt the outer race so as not to cut into the subframe. It worked really well. I also put the bushing on ice for a few days to help ease the install. It slid in relatively easily with a hammer and some grease. I rented a ball joint removal tool from Autozone, but it was too big to press in the subframe insert. Fortunately, we had a similar smaller Mitsubishi tool we could use for that.

You do not notice much difference as far as driving after the install of all 3 bushings. As a result, I would only recommend doing these if your subframe bushing is actually leaking or if you plan to have the differential out anyway for some other project and you have a couple extra hours to screw around with the rear subframe bushing.

https://cimg1.ibsrv.net/gimg/www.myg...0a47bc79b6.jpg


Installed


https://cimg5.ibsrv.net/gimg/www.myg...6d513d0115.jpg

https://cimg6.ibsrv.net/gimg/www.myg...8fe203916f.jpg

https://cimg8.ibsrv.net/gimg/www.myg...93f94c5147.jpg

Any increase in NVH?

None as far as I can tell, but I do have intakes, intake plenum, headers, cats, trans mount, and coilovers creating a fair bit of NVH already. On a stock car you may notice a slight increase.

After installing the trans mount, I'm not looking to add more NVH.

I really did not notice any additional NVH with these bushings compared to what I noticed with the trans mount, but I am a bad gauge for that if you do not have similar mods. If I were you, I would definitely wait until you actually need a new rear subframe bushing. Kind of a time suck anyway. Or maybe talk to someone else who did them with a relatively stock car to see if they noticed anything.

Here's a good (if old) step-by-step, if you wanted to do the differential bushings yourself.

http://www.the370z.com/diy-section-d...-bushings.html

It's pretty intensive, as 4DRZ implies. Unfortunately, mine's already leaking, and while it's not necessarily too important to replace until it's completely dead, it's annoying.

That's a good DIY. We did it similarly, but got through it a lot quicker with a lift and torch. It still took about 2 1/2 hours, mainly because we wasted time trying a bunch of ideas to try to push out the old bushing- none of which worked. So set aside enough time based on the tools you have available.

Z1 told me that I wouldn't need to chill it. My old bushing is gone, so I need a new one. I was planning on using these ones compared to the Whiteline ones.

Good choice. Mine seem to be holding up well and I am looking into the rear subframe bushing inserts in the future as well.

Z1 says that their bushing should be a little easier to install than the whiteline. I am having a mechanic do it, but would like it to be as easy as possible. I would almost like to get the subframe bushings. I have heard that you should freeze them, although Z1 claimed you really don't need to. I got to make a decision soon.

inserts are cake walk, with the diff bushings and the inserts my rear end is solid now. Wheel hop is to a very minimum

I froze mine, but I am not sure it made much difference. Getting the old one out is still the most difficult part of the job.

They do look much easier to install. Good to hear about the wheel hop. I thought my car was pretty solid until I was purposely spinning the wheels to get rid of some cupping and noticed the tire stripes were not solid from the wheel hop.

I have never had a torn rear bushing that I at least know of before. I saw someone saying that it was because they made fluid filled, I think it partially is due to there only being one. Other cars I have looked up had two.

Could you enlighten me on what these are? Got a link?

All I find when googling are the rear differential bushings :dunno: