Replacing GM Rear End Spherical Bushings
When I decided to do an LS swap in my 1981 Buick Regal, I knew that there were components that wouldn’t hold up to the power I planned on making. Let’s face it; you would have a hard time breaking anything in the drivetrain the original 110HP V6. The 7.5” GM 10 bolt will hold up well to all the power that the V6 will put through it, up until around 300 HP. After that, it’s a matter of time before the rear end breaks and damages you, your car, or an innocent bystander. My goal is 400+ HP, so I knew the first thing I wanted to do was to upgrade the rear end.
There are a few different options for upgrading the rear end. A Ford 9” is a great option, that Speedway Motors sells. My project is somewhat of a budget build. I was lucky to find 8.5” GM 10 bolt rear end in the junkyard. The 8.5 rear end for the G-body’s only came in the 1984-87 Oldsmobile 442 and the 1984-87 Turbo Buick Regals (Buick Grand nationals). I pulled the rear end out of the junkyard and knew I wanted to upgrade the bushings in it before I put it in the car. Upon looking for bushings for the rear end, I searched the Speedway Motors website, and I found Spherical Bushings. The spherical bushings are designed to free up suspension movement and help eliminate binding.
The first thing I needed to do to replace the bushings was to remove the old ones. This process was a little harder than it sounds, since they are pressed in, and I didn’t have a press. The first method I tried was using a block and a hammer. That worked okay, but not completely. The next method I tried was a gear puller to push them out. This way worked better as I was able to press them out completely. After the bushing were removed, I used Scotch Brite to clean up the holes a little.
With the old bushings out, I was ready to put in the new ones. I tried two different methods. For the first method I used an old seal driver. I lined up the bushing to the axle housing, then hammered it in using a hammer and the seal driver. This method worked well on the first side, but the other side was tougher to hammer in. I had a ball joint installation tool I decided to try on the side I was having trouble with. The ball joint install tool is basically a big C-clamp. After I got the bushing lined up, I tightened up the tool and it pressed in the bushing.
In conclusion, I’m happy with the bushing install. I hope this solves any binding problems that the stock bushing had. I only replaced the bushings in the rear end housing for now, but these bushings also work in the lower trailing arms if this is something that you would like to do. This is reasonably easy to install if you have the correct tools.