Will Timbren Jounce Spring TTORSEQ Make Off-Road Ride Quality Rough

Question:

How is the ride quality on the GX when going off-road unloaded? I have a 2005 GX470 with no KDSS and thinking about buying it on Etrailer and I read that it can be very stiff when hitting a bump, dip or going off-road when unloaded. Also, when the rear airbag fails during a road trip, can the Timbrens supports the load of the car and will prevent the rear sag until the airbag is replaced??

asked by: George

Expert Reply:

Timbren rear axle jounce spring kits, like # TTORSEQ that fits your 2005 Lexus GX 470, are normally not engaged with the axle with the vehicle unloaded, meaning not full of passengers and/or cargo and not loaded by trailer tongue weight.

If you were to be on a rough off-road surface with the vehicle unloaded you would be likely to feel the springs engage the axle when a wheel suddenly climbs up out of a rut. Since these springs are rated for 6000-lbs they are pretty stiff. They will support the rear end of a vehicle in the event of an air bag failure.

The Lexus dynamic suspension system (KDSS) operates in a different manner; it changes the stiffness of the interconnected front and rear stabilizers when it senses that a wheel has dropped. The Timbrens are either engaged or not, so you will feel their presence when the axle contacts them. In some conditions they would roughen the ride. Timbren part # TTORSEQ is the only rear axle option we have for the 2005 Lexus GX 470.

expert reply by: Adam R