The rear bushing are very pliable on the rear axles, which translates into loss of handling (under-steer). I used Urethane instead of Polyurethane. Urethane is toxic, unlike polyurethane, so wear gloves. Urethane is softer to avoid too much ride discomfort, compare to a hard rubber.

TOOLS
19mm socket
Ratchet 3/8
Swivel 3/8
Extension 3/8
Pocket screw driver
3M 08609
Caulking gun
Ramps
Jack

WORKING TIME
45 min

DRYING TIME
24-36 hrs (2-3 days)

DIFFICULTLY
4 (1-10)

3M Urethane:


Here is the bushing we are filling with polyurethane, we are NOT removing the axle from the car (pic is just for reference):



PROCEDURE

Step1.
Drive rear tires up ramps, so only the back of the car is in the air.
Use jack on axle (red arrow) to unload axle bolts:


Step 2.
Remove two clips and plastic cover (red arrow) to access axle bolt (green arrow):




Step3.
Remove axle bolt 19mm.
Lower rear axle using jack.
You may need a second jack to jack the side of the car to gain more access.
Outer bushing (orange arrow):


Inner bushing:


Here is the area you will fill (orange arrow) (clean first). The key is to make sure its deep in the bushing, and do not go nuts with the Urethane.


Step 4.
Do one side at a time.
Fill Left outer bushing (blue arrow):


Fill Left inner bushing (blue arrow):


Step 5.
Jack up right side while on the ramps and repeat.

Step 6.
2-3 days drying time


Check out my other DIY:
https://www.fitfreak.net/forums/2nd-...ount-fill.html

https://www.fitfreak.net/forums/2nd-...t-install.html

https://www.fitfreak.net/forums/2nd-...brake-kit.html

https://www.fitfreak.net/forums/2nd-...c-1st-gen.html

 

Good idea, but the drying time is a killer.....

Any where else to do this filling?

 

Dry time is highly dependent on temperature. I would do this on a day above 80 degrees to speed up the process. A 2 day dry time is required at least to assure that the inner filling dries. I also filled the motor mounts and dog bone.

https://www.fitfreak.net/forums/2nd-...ount-fill.html

Here's a couple of generic pics, but you can also fill the front control arms:

 

are you going to fill the arms DE36?

 

Yes next month. I've had such a hard time getting a hold of the HardRace LCA Bushings that in the mean time Im going to fill them. Probably with a harder poly than what I have been using.

 

Good shite De36.

 

I am looking for a softer ride... And I wanted to work on those arms, then I read about bushings which are hard to find here unless I import'em.....
When u do all this u are looking to limit the free movement of these bushings so u can control ur ride on the track?
Control is good, but don't like to feel vibes all the time....
I saw the 3M has a 55-60 hardness.... How about hardness of 40... Would that be silly?

 

Most people use the 3m urethane 8609 like I did because it's "softer" and less harshness for street use. Polyurethane is harder than urathane, it sound like you want to stick with 3m urethane 8609. I'm only filling the existing rubber bushing so it doesn't restrict normal motion. I didn't invent this method, I'm just one of the first to do it on a Fit. I have filled mounts on my other cars.

 

for engine mounts, 55-65A is considered "soft" yet responsive


3M should be fine, though it is medium soft-hard, it is just filling in gaps of soft rubber. You wont have a harsh ride. It will however be a bit more responsive

 

Thanks ...
will read more about the benefits /review to see if the trouble fit my needs. Filling the arm bushing seems to be tricky... small space, probably totally worth it...
Cheers

 

cant find that specific 3 M here
so i am trying to find a replacement with same specs Hardness 55-60...

 

For race applications what 3m product would work? How much of a difference are we talking for this urethane to a harder poly urethane. The car is slowly becoming more fitted for AutoX then DD.

It seems the Racehard products aren't available for the GD3 right now. Plus pressing in the bushing is not going to be fun.

Did you leave the vehicle on jack stands for 2-3 days or just set it back down. Does the vehicle weight affect the way it will dry and settle? Figured you'd want it at a neutral state as much as possible while drying.

 

For race application you would want a Polyurethane with a shore hardness of 80 to 90. In racing, the coil-over should to do all the work and not the chassis parts. I've seen solid bushings in some applications of racing.

The 8609 urethane is a Shore Hardness of 55, the equivalent of hard rubber (most likely what HardRace is using). The Poly with a SH of 80-90 is almost solid.

Yes I have other cars so I left the rear beam hanging for the 2 days. Yes the the weight will effect the way it settles, but the difference is small.

 

That's fine any name brand will work, I suggest to buy a good name brand. Dont cheap out.

 

Does anyone know the 3M part number for the harder PU?

 

I will have to look into doing this, since it doesn't cost much at all.

Do I want to fill all the space in the bushing? It is a little hard to tell in the pictures.

I will just have to put the Miata on daily duty for a few days while it dries. Oh woah is me, what a horrible fate.

 

Haven't had any luck finding a PU or U sealant/adhesive with a 70-90A hardness. Some 2 part adhesives was probably the closest to the hardness. Nothing from 3M though. Anyone know more on this?

 

Yes, fill it.

 

Polyurathane is going to be two part. Energy Suspension product:

dSt DIYMMI Do It Yourself Motor Mount Inserts - Liquid Urethane Made by dSt

Energy Suspension Control Arm Bushings

 

Damn this is a project. For a 2 part I'd have to remove everything to pour in and set. The only way I might be able to do this is tape one side good, partially tape the other side and inject PU to tape line then add more tape and fill, repeat till filled. Still a messy job.