Elephant Racing Rear Bushings

At the German AutoFest we had a chance to talk to Chuck Moreland of Elephant Racing about their PolyBronze Suspension Bearings which were advertised to work on the early short wheel base cars like mine. I've not been happy with the replacement bushings but they have been on the car for 33,000 miles so I really can not complain. The biggest problem with these are they are noisy and I've pulled them out to regrease, which works for a while. Luckily there are more choices for standard bushings now than when I bought mine in 2001, ones with more compliance.

But I decided to go another way and to get the Elephant Racing poly bronze bearings.

Both the hard plastic and products such as the Elephant Racing bearings have a reputation for being harsh riding. Perhaps so, and I'm not really not a judge because I've never had 'correct' ones installed in my car. I will say these new ones ride better than the hard plastic ones they replaced. I do not find them harsh.
030923-1931 Important If you want the ride height to remain the same after this operation and the rear geometry not to change, take some measurements as you are disassembling the suspension so you can put it back together the same way. I made three 'measurements':

  1. I spray painted the end of the spring plate to show there it matched the banana arm.
  2. I measured from the bottom of the spring plate - where the lower bolt is attached to the banana arm - to the floor.
  3. I pulled the spring plate off the torsion bar leaving the inside splines attached to the car. Then I put a piece of tape on the outside end and marked a vertical line on the tape.
030918-3759 Here is the kit. Instructions, a decal, two inner and two outer bushings, Some shim stock and some 5 mm thick washers. Each bushing is a two pieces as shown in the second row, a bronze outer bearing wrapped in a dense poly-urethane outer surface and a steel inner sleeve.
030918-3761 The first thing we discovered is that the inner bearing is smaller than the outer. The outside diameter of the spring plate carrier is the same for the inner and outer since it is constructed by welding a tube that passes through the actual spring plate.
030919-3765 Here is a view of the socket for the inner bearing. You can get an idea of the depth of the cavity by comparing with the diameter. This feature changed over time. The parts book shows a change from replaceable bushings to vulcanized ones starting with 911 chassis number 307-325 and 912 chassis number 354-938 at the end of the 1967 model year. I suspect the dimensions of this cavity changed at that time.

Notice, there are some imperfections in the socket left over from welding the body together. I ground these down with my air driven cut-off wheel so the bronze bearing would have a flatter surface to mate against.
030919-3766 Here we see the steel sleeves are fitted on the spring plate. The kit comes with shims of varying thickness that can be placed under the steel sleeves. I used 1 mil on one side and 4 mil on the other. These are the drivers side parts.
020727-1327 Here was the passenger side spring plate before cleaning.
020727-1329 And the same after sand blasting. This part required thicker shims. Obviously the sand blasting removed a couple of mils of material from the plate.
030919-3767 By the next morning the problem with the oversize diameter was fixed by cutting off the end of the inner bearing, including the sleeve. (Extra ordinary customer service! Lucky for me, Elephant Racing headquarters is just a few miles from my house).
030920-3772 The next problem found became obvious with a trial fitting of the inner bearing into the socket. The inside diameter is about 69.5 mm.
030920-3770 And the outside diameter of the poly-urethane cover is 73.8 mm. Much too large to force into the hole.
030920-3768 In proper backyard mechanic style, I fixed the diameter problem a bit at a time with a grinder that has been in the family since at least the 1960s until the outside diameter was 70.5 mm and the bushing could be forced into the socket.
030920-3773 Finally the bearing could be forced into the socket with the aide of a block of wood and the outside cover. This technique does not guarantee the inner bearing will be parallel with the mounting surface for the plate, but you want it to be as close as possible.
030920-3774 Now the torsion bar can be replaced, orienting it in the direction it came out. You can see the bearing is seated in the cavity with the zirk fitting toward the front of the car. This position provides access in order to fill with grease after the parts are all assembled. Here was my experience with the grease gun.

Final assembly was complicated for me because the design works when the two bearings are concentric. I was not able to grind the inner bearing perfectly round and concentric which caused the cover plate not to line up with the mounting holes. I needed a bit of freedom in position which was achieved by drilling out the mounting holes and placing washers under the plate of different thickness at each of the four corners. Measuring the distance of the plate to the stand offs mounted on the car was used for each of the four bolts. I made a trip to the hardware store to get a hand full of washers and then used a couple of the original thicker washers mounted under the plate.

I've now driven the car for a few days and still notice two improvements. First the rear suspension is much quieter than before. Second it rides better (although this is quite subjective and could be because of the elimination of the suspension noise). I like the solution very much and recommend it.

There are some changes required in the product design to fully support the 65-67 cars. I hope there is enough demand to justify doing that.

Elephant Racing is developing on some front suspension bushings of the same basic design for the short wheelbase cars. I expect to be a very early customer for these.
Last modified: Tue, 19 Aug 2003


Site Details. Disclaimer. Comments? Questions? Dave Hillman
Content attribted to others remains their property. Otherwise the text and images are licensed under a Creative Commons License.
Creative Commons License Valid XHTML 1.0 Transitional Valid CSS!