Part 2 Polyurethane Bushings Installation for Rear Upper and Lower Control Arms on 92-00 Lexus SC300
If you’re looking to convert the rear suspension to polyurethane bushings as well, don’t expect to accomplish everything in just a day, even with some help on hand. The rear suspension is a five link suspension, consisting of the upper control arm, a lower control arm, toe rod, traction rod and the coilover strut. Like the front Prothane polyurethane bushings kit, it is also a complete set for the rear, that even comes with the bushings for where the traction rod is attached to the hub. Which we did not use since removing the hub requires the axel to be unbolted as well.
Like last time, it’s always a good idea to mark your camber and toe bolts, so the alignment wouldn’t be so bad once everything is back together. And again, alignment is still a must.
Note: If alignment is so far off, the car can feel wobbly and almost uncontrollably bad for daily driving. Not to mention can also damage your tires and suspension prematurely.
The bushings sizes slightly vary, so pairing them up ahead of time would be a good idea to make life easier later on.
The metal sleeves/spacers also vary in size. It is essential to have them paired up as well. And a bottle of beer too would help with this job.
You can start pressing out the bushings for rear lower suspension parts like how we did it in the front upper control arm. Here is the traction/strut rod, toe rod and lower control arm.
The only different bushing we encountered in the rear lower suspension parts was the traction/strut rod.
The traction/strut rod's bushing is again molded between an outer and inner metal sleeves, and will not simply pop out without a little bit of backyard engineering.
Simply using the hyrdaulic press to push out the bushing doesn't work, as the rubber will just stretch as the outer metal sleeve is just too tight to slide out. Some people chose to torch it and just dremel or saw off the outer metal sleeve in half, which needs to be removed regardless, for the polyurethane bushings to fit.
Having done this a couple of times, I found this to be the easiest and most logical way to take the entire thing out in one try. A size 32mm socket fits perfectly over the entire bushing, and works like a charm in taking the whole bushing out with the metals sleeves.
Position the 32mm socket carefully over the bushing, and start pumping it out.
Here is that darn bushing out.
After the traction rod's bushings are out, just simply grease up the polyurethane bushings and metal sleeves, and pop them in their respective suspension parts (according to their sizes of course) and you're done with the rear lower suspension parts.
One would like to start thinking that it's going to be a breeze from here on out since you only have one more suspension part left to deal with, but surprise, surprise... yes this last one is truly going to be a surprise.
Unbolt the ABS sensor from the hub.
And it's wire clamp that's attached to the rear upper control arm.
Take off the 19mm nut that holds the ball joint bolt unto the hub.
The pitman arm puller won't work with the rear upper control arms due to the tight space with all the suspension components in place. Best way to take the ball joints bolt off is to either hit it with a hammer or use a ball joint separator. Both work, but this works faster. Give it a couple solid hits and it will break loose.
Once the ball joint breaks loose from the hub, just pull it out and make sure to secure the hub by tying it somewhere. It is not ideal to have the weight of the hub on the axles.
Loosen the two 19mm bolts that hold the rear upper control arms to the rear subframe with a breaker bar. It's on there pretty tight.
Here is the rear upper control arm.
The rear upper control arm bushing design is also the surprise by the way. It consist of an outer metal sleeve that curves outward flush on the edge of the "ear", that will prevent it from going out the other way. Then there's the center bolt spacer that has multiple layers of metal shock absorbing cylinders (just a guess) that won't be reused so it doesn't matter.
Again, I've done this a couple of times already, and I know what would work faster and more effective at this point.
The problem with the outer metal sleeve curving outward on the edge of the "ear" was that there's not enough surface for the arbor plates to hold on too while you're trying to press it out. To fix that issue, I just hit the edge of the metal sleeves with a chisel to open it up a little bit. No need to do the entire edge and no need to open it up all the way, just enough ground for the arbor plates to hold on to.
This should be enough.
Like I said, because the bushings would only come out one way, due to the outer metal sleeve curved outward at the edge, we're going to need to torch at least one side again to access the other bushing with the hydraulic press.
Like last time, prying out the center metal sleeve with a screwdriver helps burn the rubber inside faster.
Here is that shock absorber looking bolt spacer I was talking about.
You should now be left with this.
Make sure it's cool to the touch before working on it again!
Here's a couple pics of how the outer metal sleeve curves outward at the edge of the control arm "ear".
View from the other side.
Grab the 32mm socket we used for the traction rod, and assemble it with a socket extension like this.
Now this is why we chiselled the outer metal sleeve to open up enough ground for the arbor plates to hold on to.
And this is why we only torched one bushing on each control arm. With one bushing out, we can press the other bushing with the makeshift tool we made and push it out the same direction it came in.
Take a second to make sure that everything is aligned and balanced perfectly before proceeding in pressing the bushing out or you'll risk large heavy metal plates flying all over the place and injuring yourself.
Watch closely for the bushing coming out to see if there's any problem with the assembly so you don't waste time and don't cause accidents.
Here is the mushroom looking bushing out of the control arm.
Flip the control arm to the other side, and position the tool for the metal sleeve.
As you can see, sometimes it requires us to use both hands... and a foot, to keep stuff from going everywhere.
Watch your other foot!
And voila! The metal sleeve is out.
You can finally install the last set of polyurethane bushings and metal sleeves.
Remember the washer and the weird looking nut when you took the rear upper control arm off? It was designed with a tab to stop itself from rotating with the bolt as you tighten it down to spec.
Installation of the rear upper control arms will be a bit of squeaze like the front lower control arms due to the stiffer and meatier bushings. Once you figure out how to get the control arms into position, align it with the subrframe holes for the bolts. The washer goes in first before the nut, of course.
Getting the nut in place is going to be a tight squeaze for guys with big hands. This slot in between the subframe and the chassis might work if you have steady hands.
The nut has a clever design, but not so good in execution. The subframe has a wall at the edge, where the tab is supposed to jam itself and prevent the nut from rotating. The wall curves up smoothly at the edge, and instead of the tab hitting the wall, it slides up the curve and just lose its purpose of design. The first time I did this job, my SC was on a lift, and we still dealt with the same issue.
It helps to hold the nut while you tighten the bolt as much as you can by hand.
Then you carefully balance and jam the tab of the nut with a screwdriver, then proceed with tightening the bolt from the other side. Once the washer and the nut sits flush on the subframe, you can let go of the screwdriver and let the tab do its job. Tighten them to spec and assemble the rest of the suspension parts.
Once you have replaced every single suspension bushing your car has, it will be a totally new car from there on. The stiffer polyurethane bushings never wear out, and will give you car an overall sportier feel. Yes, it will be way stiffer, but you should've known that that would be the results to begin with. Always test drive your car in a short backroad after you work on it, to find out if there's anything wrong or if you forgot to do anything else by accident before hitting the big open road.
Disclaimer: Use at your own risk. If you don't feel comfortable doing a procedure then don't do it. This information is to be used as a guide and is for illustration purposes only. By no means is my site a definitive source for the procedures listed; it is simply how I or the tutorial contributor did things. The tutorial contributor, and I are not responsible in any way for anything that happens as a result of following these guides.
Safety First: When working on your car put safety first. Use common sense and be careful. If you're doing electrical work disconnect the battery. If you need to jack up the car use jack stands and wheel blocks. Common sense is the key.