Trailing Arm Replacement Solid Bushings
This monoball bushing set, is manufactured by VAC Motorsports, and is designed to eliminate the excessive unwanted bump steer which is inherent in the stock rubber bushings or even the best poly bushings in your BMW E36, E46 and related Z4 chassis. By substituting the stock bushing with a premium spherical ball joint, (replaceable), mounted in an aluminum housing, these complete bushing replacements prevent toe changes caused by bushing flex during cornering and can also help prevent tearing of the trailing arm mounts.Premium spherical bearings are used for long life, precision, and quieter operation from the suspension components. While these don't decrease ride quality, they can transfer a bit more road noise over irregularities.
Sold in pairs (L&R) for E36, E46, and Z4 chassis.
Quick FAQ
Q: Do these require regular maintenance or greasing?
No. The monoballs use high-quality PTFE-lined spherical bearings, which are self-lubricating. No periodic greasing or adjustment is required.
Q: Will these make my car uncomfortable on the street?
Ride quality remains very close to stock. You may notice a slight increase in road noise over sharp bumps, but no harshness or vibration under normal driving.
Q: How long do the monoballs typically last?
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Street use:
40,000-60,000 miles
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Street + track/autocross:
25,000-40,000 miles
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Dedicated track/drift/hill climb:
1-3 seasons
Actual life depends on driving style, road conditions, and alignment.
Q: What parts wear out over time?
Only the spherical bearing is a wear item. The CNC-machined aluminum housing is designed to last the life of the car.
Q: Can they be rebuilt instead of replaced?
Yes. The spherical bearing is replaceable, allowing the bushing to be refreshed without replacing the housing.
Q: How do I know when service is needed?
Signs include increased play, clunking during throttle transitions, unstable alignment, or visible movement during inspection.
Q: Are these better than polyurethane bushings?
Yes--monoballs eliminate toe changes caused by bushing flex. Poly bushings still deflect under load; monoballs do not.
Q: Are these suitable for motorsports?
Absolutely. Commonly used in track, autocross, drift, rally, and hill climb applications where rear toe stability is critical.
Q: What vehicles are supported?
BMW E36, E46, and Z4 chassis. Sold as a complete left & right pair.