Monthly Archives: June 2020

A90 Supra S.TECH Rear Bump Stop Modification

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With the newly released S.TECH lowering springs for the A90 Toyota Supra, we wanted to put a notice out to owners about modifications needed to the rear bump stops.

S.TECH Lowering Spring set part number: SKTJ4-S1B00

Our S.TECH spring kit (part number: SKTJ4-S1B00) includes a pair of bump stops and dust boots specifically for the rear shock absorber. However, it is to be used in conjunction with a modified OEM bump stop.

Please follow along as we show you what needs to be done.

First, the rear shock absorber mount needs to be removed. Then, the the OEM bump stop can be pulled out of the mount. Now, the OEM dust boot is simply press fitted around the OEM bump stop. You can just pull the dust boot out, or you can leave it attached. Either way, the OEM bump stop needs to be trimmed significantly, and the portion to be removed also removes the OEM dust boot. Our included TEIN dust boot will replace this piece.

The rear shock absorber mount needs to be removed from the shock absorber assembly.

With the OEM bump stop removed, you need to measure 20mm from the top of the bump stop (widest portion) down and mark this location. This 20mm piece will be reinstalled in the rear shock absorber mount. You can use a razor blade (utility knife will do fine) to cut the bottom portion of the OEM bump stop off.

The OEM bump stop and OEM dust boot are assembled as one piece. The OEM dust boot is easily removed by pulling it off the OEM dust boot.
The top of the OEM bump stop will need to be remained. This should be 20mm thick after trimming.

Now, the included TEIN bump stop also needs to be trimmed. 10mm needs to be trimmed off the bottom (narrow portion) of the TEIN bump stop.

The included TEIN bump stop also needs to be trimmed, too. The bottom portion needs 10mm but from the bottom, which is the narrow portion of the bump stop.
A utility knife makes trimming of the OEM and TEIN bump stop easy work. Just use caution when cutting.

This picture shows how it is to look on the rear shock absorber (without the TEIN dust boot, for example only) along with the trimmed OEM bump stop.

For reinstallation, hand fit the modified TEIN bump stop onto the piston rod. Then, fit the TEIN dust boot onto the piston rod.

Then, reinstall the rear shock absorber mount (with the trimmed OEM bump stop hand pressed in) onto the piston rod. Now you can tighten the rear shock absorber mount with the 16mm flange nut.

Make sure the TEIN dust boot and bump stop are placed up against the trimmed OEM bump stop (basically you are going to sandwich the top of the TEIN dust boot against the trimmed OEM bump stop and trimmed TEIN bump stop).

The final assembly should look like this. The TEIN bump stop is covered by the TEIN dust boot, and both pieces are pushed up against the trimmed OEM bump stop. The TEIN bump stop is a tight fit around the piston rod in order to keep the TEIN dust boot in place and to protect the piston rod from any debris damage while driving.

The rear shock absorber assembly is now ready to be installed back onto the vehicle.