Bearing Carrier TLZ for X4 Jacob's Ladder Left

• Fits Z-link (trailing arm) rear configuration. Does not work with wishbones. Fits Hyper X4 and other manufacturer's Chassis.
• Fits 1-3/4" axle.
• 4-1/2", 5" and 5-1/2" spread.

We recommend the bearings be greased before the first use with DAYLube™ High Performance Grease 77-800 & 77-805.

Uses (1) 7/16-20 x 2-3/4" HHCS with (1) 7/16-20 nylock half nut for the torsion arm bolt, (2) 5/16-18 x 2" SHCS for standoff.

What changes do moving the upper and lower mounting points on the bearing carrier have?

On a Z-link car, it is actually pretty complicated and not real straight forward on what those different mounting points do to the car handling. But here are some general concepts.

Lowering the top link on the bearing carrier and leaving the point on the car the same, the chassis will have more anti-squat. More anti-squat will generate more weight transfer from the front to back under acceleration because the chassis center of gravity height will be higher as the anti-squat geometry will resist the rear squat of the car.

Moving the torsion arm to the lower hole closer to the center of the axle will make the rear torsion arm angle less which will generally make the effective spring rate less, which usually make the car tighter if done on the right, and looser if done on the left.

So those are fairly easy and straight forward, the harder part to figure out is the rear steer effects of these changes. Rear steer is how the axle moves forward and back as the rear axle moves up and down. As the right side of the axle is steered forward the car will get tighter as it will point the front of the car toward the outside wall! Changing the mounting points on the bearing carrier will change when and how much the rear of the car is steered. And you have to consider the left and the right side and how it is steering car at any particular roll angle. This is hard to figure out when and how much the car is rolling especially with the wing on. The car will roll left on entry then roll right on exit. How much and exactly when depends on the size, shape and conditions of the track. Also, the ride heights you are running (how high you block the car) will change these transition points as well. Take the stops off your bars with the car on stands and move the rear axle up and down and you will see.

Lowering the top link on the right rear will move the right rear back more as the car rolls right making the car looser when rolled right. Moving the bottom arm closer to the center of the axle (up) will make the right rear steer forward more making the car tighter. The effects are the exact opposite on the left rear as far as tight and loose go.