Taking the opposite point of view of the previous post, I really like my Bilstein shocks and firm ride. To repair my defective suspension, I first picked the OME 2906 rear springs and then studied the available shock absorbers. The following statement from the Bilstein installation instructions convinced me that the 5100's were optimally engineered for the moderate lift and spring rate of the 906 springs: *PLEASE NOTE: For optimum ride performance it is recommended that 2" lift rear coil springs be installed (220 lb/in) in conjunction with the 5100 series front (24-248730) and rear (24-249966) shock absorbers.* With an empty vehicle, the 5100's seem rather rough; half loaded with four people in the vehicle, they seem to smooth out and to be just right; loaded to the GVWR with 1300 lb in the vehicle, they get slightly bouncy on longer humps or dips in the road. Seems to me to be an excellent balance.
I cannot discern any problem with the original front springs, but I have always wanted a winch and I think I may try tall '99 front springs if I replace the front bumper and add the winch. My upper support (a.k.a. top hat) and cushions (bushings) and retainers (washers) are in poor shape, but at the instruction of Bilstein, I reused them. I will replace them with new Toyota top hat, bushing and washers if I install new springs. Toyota specifies a Lower Retainer, Upper Support, Cushion, and Upper Retainer for t he top of the strut assembly. Judging by the picture of the upper support, it incorporates a large retainer and cushion on the bottom side to go next to the lower retainer; apparently the other cushion & retainer go above the top hat next to the Bilstein-supplied nut.
For the top mounts of the rear shocks, Bilstein supplies three washers and two bushings with a crystal clear diagram of how they are to be installed. The top nut on the rear was rather difficult to install. I ended up buying an offset 14 mm wrench to hold the nut, and a 5 mm allen socket for the ratchet wrench to turn the shaft of the shock.
