Rear Shock

1985 RZ350

Replacing the R6 Shock Bushings

In order to make the upper and lower eye openings in the R6 shock be the same as the original you need to remove the existing R6 bushings and replace them with new ones. The R6 shock has a 12mm bolt hole at the top and we need an 8mm one.

So the easiest way to change them out is to use a system of threaded rod and nuts/washers with a spacer and gradually draw out the old bushing. The idea is that the spacer rests on the cast part of the shock and the nut on the left is used as a stop. When you tighten the nuts together, the race is drawn out of the shock in to the spacer area.

In the shot above you can see how the bushing is being drawn out and...

...I removed the spacer halfway through the process to show how the bushing is being drawn in to the spacer area. You could just try and hammer them out but with about $2 in hardware store parts you can do it this way with no possible damage to the shock.

The bottom eye is similar but you need to pry out the two small oil seals and throw them away before drawing the caged roller bearing out.

On the bottom I was able to use a similar system but used a socket as the spacer.

For the upper bushings you need to get two McMaster Carr bushings - part number 6659 K36 Metric SAE 841 Bronze Flanged Bearings which have an 18mm shaft diameter, 22mm outside diameter (OD) and 18mm length. These need to be placed in the upper eye in such a way that you have about the same amount sticking out on each side. I did it by placing them all in a vise and carefully tighteneing it. If one side went in a little further, I removed it from the vice and used a little hammer to tap it in. Finally they touched inside the eye and look pretty centered.

The final step for the upper bushing is to remove the steel sleeve from the existing shock....

...and push it in to the R6 bushings you just replaced.It should just push in with finger force but you can tap it in if necessary.

The bottom of the shock is very similar using a spacer to remove the caged bearing, and inserting the two bushings from either side. The difference is the bushings are two McMaster Carr bushings - part number 6659 K42 Metric SAE 841 Bronze Flanged Bearings which have an 20mm shaft diameter, 24mm outside diameter (OD) and 20mm length.

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