GKTech - Rear subframe slip-in collars R32 / R33 / S14 / S13 - rear-cllr The GKTECH rear subframe collars are used to eliminate axle tramp and to also tighten up the rear end giving more precise control of the vehicle under harsh driving conditions.- CNC Machined- 8 Piece Set VEHICLE COMPATIBILITY Nissan CEFIRO A31R32 SKYLINE GTRR32 SKYLINE GTS-TR33 SKYLINE GTRR33 SKYLINE GTS-TR34 SKYLINE GT-TR34 SKYLINE GTRS13 KA24 240SXS13 KA24 HATCHS13 SR20 240SX HATCHS13 SR20 240SX/SILVIAS14 240SX/SILVIAS15 SILVIAZ32 300ZX What’s the advantage of the slip in collars? The slip in collars sit above and below your standard subframe bushes and essentially compact them. This results in less movement of the subframe and eliminates axle tramp and increases stiffness in the rear of the vehicle. How hard are these to install? Installation is pretty straight forward and the slip in collars are as the name suggests, slip in. Installation shouldn’t take you longer than 45 minutes - 1 hour. Is there a noticeable difference in the feel of the car when driving around normally? Ie. any vibrations? If you don't already have coilovers and other noisy parts then you will notice an increase in NVH however if you're running coilovers, there's no notable difference