The Install Series: Powerflex Bushings

Gutted Evo 6 on Jack Stands

The winter build continues on our Budget Time Attack Evo 6!

This week we will be focusing on fixing an issue any Evo owner is likely familiar with – the suspension.

Evo owners know all too well the aggressive clunk they get from the car when shifting gears like a mad pro! So let’s fix that issue up for you. It’s time for some new bushings to replace those worn out rear differential bushings. We’ll be showing you how to install a set of Powerflex bushings (PFR44-120 and PFR44-121), but the process is pretty much the same for all poly bushings out there.

As we were pulling the suspension off of the time attack Evo, we couldn’t help but notice a little issue with our rear differential carrier. The bushings were extremely worn, and in some cases the rubber was completely torn out. This explained why we had been experiencing such issues with clunking when shifting.

The first step was to source some new bushings. There are several options out there for your Evo, but you must be careful when purchasing the bushings. In the case of the rear differential, there are 2 sets you need; the front bushings, and the rear bushings. As well, the front bushings are different depending on if you have an AYC equipped model, or not. The rear bushings, however, are the same for all models. And just to clear it up, this applies to all Evos, 4 through 9.

Now this is not some shameless plug. Like we said, there are several options out there for bushings including the OEM set, Ralliart, Whiteline, Powerflex, and SuperPro. Don’t be afraid to research a little and decide which one is best for you. Since we’re based in Canada, Powerflex ended up being the easiest for us to source at a reasonable price.

So let’s get to the install. Our Budget Time Attack Evo 6 is a GSR model equipped with an AYC rear differential. The part numbers we are installing are PFR44-120 and PFR44-121. As well, we decided to go with the Black Series since this is a track dedicated vehicle. If you are working on a daily driver, you may not want to go as stiff.

For our install, we are fortunate to already have the rear differential out of the car, and the carrier arm and mustache bar removed. However, for most of you, you will need to start by removing the rear differential and sub frame. Check out this great write up for removing your diff.

With the rear diff off the car and the carriers unbolted, you’re going to need to remove those old worn bushings. There are a couple of ways to get this done. The easiest is to take it to a shop with a hydraulic press. This is quick, easy, and eliminates the risk of you damaging your differential carriers. On the other hand, if you’re adventurous, you may try removing them yourself. One way to achieve this is with a hacksaw. Begin by cutting out the rubber on your stock bushing. Then, insert a hacksaw blade into the now hollowed out bushing. Attach the blade to your hacksaw, and start to cut away at the metal sleeve. Be very careful not to cut into the differential carrier as you do this. When you’ve cut all the way through the sleeve, it’s now just a matter of knocking out the bushing.

Let’s start with the front carrier and PFR44-120. Start by cleaning up the bore in the carrier with a cloth. As well, you will want to take a round file around the edge of the bore to remove any jagged or uneven edges, as well as give it a slight chamfer. This will help the bushing to slide in. Again, clean up the arm before continuing on. Now the bushing you received has 3 pieces to it. The two polyurethane pieces, and the inner steel sleeve. In the case of PFR44-120, the two poly mounts are the same dimensions, so there is no wrong way to install them.

You should have received a packet of grease with your new bushings, and you are going to be using this a lot. Apply the grease to the inside and outside of the bushings. Press the first half of the bushing into the arm. We opted to use an arbor press for this step, but you should be able to muscle it in there too. Repeat this for the other half of the bushing. Now you need to insert the metal sleeve into the bushings. Again, apply grease, and it should only take a bit of light tapping with a hammer. Be sure not to damage the sleeve. A rubber mallet is great in this situation.

Repeat the process for the other side of the carrier. With that, you should be all ready to install the front carrier back into the car. Slide the carrier onto the 2 bolts underneath the car. You will then reuse the bottom washer from the stock bushing, followed by the nut. Torque the nuts to 118 Nm (87 ft-lb).

Now for the rear bushings (PFR44-121). For the mustache bar (rear carrier), you will again be greasing up all the areas where rubber and metal contact on the bushings. Insert the two halves (once again, they are both the same size) into the cleaned up bore on the arm. Insert the steel sleeve into the bushings and marvel at the easy part all done!

Now comes the hard part. Installing this mustache bar back into the subframe. There is nothing fun about this, and you will really start to doubt your skills as a DIY mechanic at this point. The tolerance between the bushings and the respective mount bracket on the subframe is extremely tight. It will be very helpful if you chamfer the edge of the mounting bracket with a file, much like you did for the bore on the arms. This will allow the bushing to ease into the bracket without damaging the rubber.

You are going to apply a very liberal amount of grease to the sides of the bushings, as well as the respective mount on the subframe. Next, you will need to rock the bushing back and forth as you slowly press them into the brackets. This will truly be an exercise in patience. However, once you finally have the bushings started into the brackets, you can bring out the sledge hammer! Using a piece of wood, you can smack the bushing into place with the hammer. This will take a while to get the holes lined up for the bolts to slide in. Once they are in, you can torque them to 88 Nm (65 ft-lb).

Once you’ve gotten all the cursing out of the way and have taken out all your anger with the sledge hammer, you should be looking at a finished product. Congratulations, because you now have those suckers installed. The last thing to do is bolt everything back up! This is the reverse of removing the rear differential, but with a little twist. Be sure to refer to the Evo workshop manual, as there is a specific order to bolting up the subframe to the chassis. If you don’t have a copy of this manual yet, check out this site. It is also worth noting, the workshop manual for the Evo 6 is a supplement to the 4/5 manual, so you will want to refer to that one as well.

We hope this install is helpful for those of you wanting to tackle this job. It is a relatively easy job up until the reinstall of the mustache bar in the subframe. If you have any questions, hit us up in the comment section.