My JZS171 came with Buddyclub coilovers already installed all round. The spring rates for these coilovers are 14kg/mm front and 10kg/mm rear. The rear coilovers have always had a slight knocking sound in the rear, ever since I purchased the car.
I searched everywhere looking for new lower bushes for the rear coilovers. Without success i decided to measure up the old ones and make new custom ones.
After trawling through the Nolathane and SuperPro catalogues for a polyurethane bush, the closest one i could find was the SPF2795 from SuperPro. It had the correct shoulder, inner and outer dimensions etc, but was slightly too short. This was fine as i intended to make 1 bush from 2 and insert from either side.
I cut the old worn bushes off from one side, then knocked them out using a punch.
Then I measured up the inner metal sleeve at 54mm and divided by two. This meant the new bushes I had to cut at 27mm each.
I inserted the halves into the coilovers after cutting them to length with a bandsaw and applying some grease to the outer sides.
Then I pushed the metal insert through the centre.
The car has been test driven and as a result, found to have its rear clunking noise minimized dramatically.
I hope this article and photos is of help to others.
PS. JZX110 BuddyClub coilover lower bushes are replaceable in the same manner, since both the JZS171 and JZX110 utilize the same suspension.