So while doing a little research on polyurethane complete differential bushing sets I came across something that triggered a question. I noticed a significant price difference among the more popular brands. I found a set of ES bushings, sold by Z1 for $48, which require the factory sleeve insert to be re-used. Z1 sells their own brand of differential bushings for $90 which they say include an "upgraded" insert. Additionally, I found a set of Whiteline bushings (appear to come with the insert) for $103, and Prothane bushings (again, re-use factory insert) for $32.

What, if any, dramatic differences are there among the brands? Durometer rating maybe? Durability and overall longevity? Is it simply the websites that I came across these prices on? I know that the "upgraded" inserts can't account for the $50 - $70 difference.

Here are links for reference:

Z1- Brand Bushings:
https://www.z1motorsports.com/z1-pro...s-p-10356.html

ES Bushings sold by Z1:
https://www.z1motorsports.com/suspen...CABEgKuJPD_BwE

Whiteline Bushings:
https://whiteheadperformance.com/pro...35-03-07-copy/

Prothane Bushings:
https://www.prothanesuspensionparts.com/141603

 

If i were to do my diff again, would use solids.
The ES and prothane will be very similar. There are some posts a few years back where people had issues with the main rear bushing pushing out of the subframe. Installed this bushing backwards from the inside of the subframe in order to keep it from pushing out. Personally using the ES. They do feel great just not sure how long they will last.
Whiteline many speak well of.
z1 urethane if not mistake are super pro bushings from australia. may be mistake on this but look identical. Very good brand from what i have heard.
Honestly i would go spl solids, still may at some point down the road do this.

One thing to keep in mind, what do you want to do with subframe bushings down the road. If you go solid subframe and diff, i hear can get really noisey. Some aftermarket diffs can get even louder. I don't mind noise for the most part but opted for urethane subframe incase i decide to upgrade to solid diff later to limit nvh some.

 

So it actually is a case of better quality, not just "paying for the name". I appreciate it, Rusty.

Planning to do poly subframe bushings as well. The car is not strictly track, otherwise I would do solids. The poly SF and diff bushings for me were the best choice due to balance and consistency across the drivetrain (poly motor and trans mount already). I want to still allow everything to have that little bit of flexibility that full solids do not offer and to keep the car somewhat tame on the inside.

 

Although it is a little hard to see, i reversed my ES bushing so it wouldn't slide out. The dif is a bit harder to install this way but does go in very firm. Lowest cost option but probably the easiest to install albeit the prothane is surely the same.
The z1 and white line you will probably want to freeze to make install easier.

 

Planning to do the subframe bushings and differential bushings at the same time. Figured there was no reason to unbolt things twice and the extra room may make it easier to work with. While the subframe is out might as well replace the rear suspension bushings too, right? And since I would need an alignment I may as well go ahead and replace the front suspension and steering bushings too!

Side note, did you notice any change with that aftermarket brace?

 

Only difference i noticed with the brace is room for the exhuast. Weight and handling seemed about the same. The condition of the stock brace was why i changed. If you want to look in my albums you can see how beat up the stocker was.
Pulling the diff is a fairly quick job and don't have to drop all that you would need to drop the subframe. Might speed things up about an hour if you do the subframe at the same time. Both sets of bushings won't see you back much. Only thing you won't be able to notice how much the dif and subframe bushings help individually. Changing both together will be a drastic change

 

I've had both the Whiteline and Z1 in my hands and my vote goes for Z1 and those were the ones I went with. Alternatively if you want something easy you can get Z1 collars for the subframe. I was going to do the Whiteline subframe bushings but opted for the collars because of easier install. Still have my Whitelines hanging around I'll give you a deal on them if you want to go that route lol

 

Looking forward to experiencing the difference once those are replaced. I'm sure once I do my complete overhaul it will be like a brand new car.


I appreciate it, bud! I am going to go with Z1 since I already have their brand motor and trans mounts. I like to keep consistent among brands unless one brand is good for one thing and another is good for something else, you know?

 

Yup same, I had a lot of Whiteline stuff but when I saw the diff bushings I wasn't comfortable with how they looked. Their subframe bushings look fine tho and I don't think Z1 has poly bushings for the subframe, only the collars. It's the Whiteline subframe bushing that I have laying around, don't know if I'll ever use them lol.

 

When it was time to replace my rear diff bushing my installer told me I had three options: use another OEM bushing and probably have to redo this if I intended on keeping/driving the car, use a poly bushing and I'd eventually hear some really loud squeak noise no matter what he did to it, or I could go solid aluminum and do it once and never be bothered with it again. I chose SIKKY solid bushings and never looked back.

 

You will NEVER get squeaks from the diff, they don't move like suspension does. If a tech ever told me that I'd burn rubber out the place. Not that I let many techs touch my car. They aren't as good as me lol

 

There is a hard rubber diff bushing available, given the amount of heat both from the diff itself and the exhaust I'm not convinced that urethane is a good option for that particular application. How good the hard rubber one is? All I know is that it looks like a suitable option.

 

I mean, plenty of folks use poly engine mounts and they do fine. One of my exhaust pipes is pretty darn close to the bushing so I wrapped a section with heat wrap. Who sells hard rubber?

 

On the ES do you still have to remove the outer steel sleeve?