What exactly is the rear lower control arm inner bushing, and how is it different from the knuckle bushing?

The rear lower control arm inner bushing (this listing) is the large rubber bushing at the inboard end of the rear lower control arm; the point where the arm attaches to the rear subframe. The SPL RLCB E9X (a separate product) is the bushing at the outboard end of the lower control arm, where it attaches to the rear knuckle. Both are important bushing positions in the rear lower arm assembly; each one is a separate purchase and addresses a different connection point. A complete rear lower arm spherical bushing conversion addresses both the inner subframe connection (this product) and the outer knuckle connection (RLCB E9X).

Why does the OEM rubber inner bushing cause camber and toe to change dynamically?

The factory rubber bushing at the rear lower control arm inner position is under load every time the suspension sees lateral force, braking force, or bump input. When the rubber compresses under those loads, the lower control arm moves slightly relative to the subframe; that movement changes both the camber and toe at the rear wheel. On wide-tire, high-grip builds that generate more lateral load than stock, the deflection is more significant and the geometry consequences more pronounced. The SPL RLBI E9X holds the arm position fixed under all load conditions; the geometry set at the alignment rack is the geometry the car runs during a corner.

What OEM part number does the SPL RLBI E9X replace?

The SPL RLBI E9X replaces BMW OEM part number 33326770829, which is the factory rubber rear lower control arm inner bushing used across the E80/E82/E82M, E90-E93, and F80/F82/F83/F87 platforms.

Why does SPL use the largest possible FK bearing in this location?

A larger bearing distributes the same load over more contact surface area, which reduces specific loading on both the bearing and the housing, slows wear, and produces lower NVH than a smaller bearing handling the same forces. SPL specifically uses the largest possible bearing with the tightest fit FK offers at this location because the OEM bushing is large; using an undersized replacement bearing in an oversized housing would reduce the engineering benefit. The bearing size matches the scale of the load.

Should this bushing be replaced at the same time as the outer knuckle bushing?

Ideally yes. Replacing the inner subframe bushing while leaving the outer knuckle connection in factory rubber keeps a deflection point that partially offsets the gains from the inner bushing upgrade. A complete rear lower arm spherical conversion addresses both the inner (this product, SPL RLBI E9X) and the outer knuckle (SPL RLCB E9X) positions simultaneously for the full benefit.

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Description

SPL Parts Rear Lower Control Arm Inner Bushing for E8x / E9x / F8x BMW 1 & 3 Series / M2 / M3 / M4

The rear lower control arm on the E8x, E9x, and F8x BMW connects to the subframe through a large rubber inner bushing; one of the most deflection-prone rubber points in the rear suspension. This is not a small bushing doing minor NVH work. It is a primary structural connection between the lower arm and the subframe, and the rubber at that connection compresses and deflects under the full lateral and longitudinal load of hard cornering, braking, and acceleration. When it deflects, the arm moves; camber and toe change dynamically during a corner, right when the tire contact patch and rear grip balance need to be most consistent. On high-grip cars with wider tires that generate more lateral load, the deflection is more pronounced and the geometry consequences more significant. The SPL RLBI E9X replaces that rubber with an F1-spec, self-cleaning PTFE-lined FK spherical bearing pressed into CNC-machined 6061-T6 aluminum bearing shells and spacers. The bearing articulates freely through the full suspension range of motion without deflecting, holding the lower control arm in its set position under all load conditions. Camber and toe stay where they were aligned rather than shifting under load; the rear suspension delivers what the alignment targeted rather than what the rubber allows after deflection.

Features

Replaces the large factory rubber rear lower control arm inner bushing with F1-spec, self-cleaning PTFE-lined FK spherical bearings; eliminates bushing deflection and binding at the primary subframe connection of the rear lower control arm
Preserves rear camber and toe geometry under bump; arm holds its set position through the full suspension range of motion under cornering, braking, and acceleration loads
Largest possible FK spherical bearing used in this location with the tightest available fit; distributes load over maximum contact area for improved longevity and lower NVH versus a smaller bearing at the same load
CNC-machined 6061-T6 aluminum bearing shells and spacers; precise fit to the OEM control arm and subframe connection
Maintenance-free PTFE liner; self-cleaning; no greasing required
Particularly beneficial on wide-tire, high-grip builds where lateral loads generate proportionally more deflection in the factory rubber

Specifications

Material: CNC-machined billet aluminum or PTFE-lined spherical bearing (per part)
Replaces: OEM rubber bushing
Adjustment: None (solid replacement)
Origin: Made in the USA

Applications

BMW 118d: E81, E87 | 2004-2013
BMW 120d: E81, E87 | 2004-2013
BMW 123d: E81, E87 | 2007-2013
BMW 116i: E81, E87 | 2004-2013
BMW 118i: E81, E87 | 2004-2013
BMW 120i: E81, E87 | 2004-2013
BMW 125i: E81, E87 | 2007-2013
BMW 128i: E82, E88 | 2007-2013
BMW 130i: E81, E87 | 2004-2013
BMW 135i: E82, E88 | 2007-2013
BMW 1M Coupé: E82 | 2011-2012
BMW 318d: E90, E91, E92, E93 | 2005-2013
BMW 320d: E90, E91, E92, E93 | 2005-2013
BMW 325d: E90, E91, E92, E93 | 2005-2013
BMW 330d: E90, E91, E92, E93 | 2005-2013
BMW 335d: E90, E91, E92, E93 | 2006-2013
BMW 316i: E90, E91, E92, E93 | 2005-2013
BMW 318i: E90, E91, E92, E93 | 2005-2013
BMW 320i: E90, E91, E92, E93 | 2005-2013
BMW 323i: E90, E91, E92, E93 | 2005-2011
BMW 325i: E90, E91, E92, E93 | 2005-2013
BMW 328i: E90, E91, E92, E93 | 2005-2013
BMW 330i: E90, E91, E92, E93 | 2005-2013
BMW 335i: E90, E91, E92, E93 | 2006-2013
BMW M2: F87 | 2016-2021
BMW M3: E90, E92, E93, F80 | 2007-2018
BMW M4: F82, F83 | 2014-2020

Notes

Installation Instructions
SPL components are made-to-order in the USA; build time will be confirmed at the time of order.

Frequently Asked Questions

What exactly is the rear lower control arm inner bushing, and how is it different from the knuckle bushing? The rear lower control arm inner bushing is the large rubber bushing at the inboard end of the rear lower control arm; the point where the arm attaches to the rear subframe. The SPL RLCB E9X is the bushing at the outboard end of the lower control arm, where it attaches to the rear knuckle. Both are important bushing positions in the rear lower arm assembly; each one is a separate purchase and addresses a different connection point. A complete rear lower arm spherical bushing conversion addresses both the inner subframe connection and the outer knuckle connection.
Why does the OEM rubber inner bushing cause camber and toe to change dynamically? The factory rubber bushing at the rear lower control arm inner position is under load every time the suspension sees lateral force, braking force, or bump input. When the rubber compresses under those loads, the lower control arm moves slightly inboard or outboard relative to the subframe; that movement changes both the camber and toe at the rear wheel. On wide-tire, high-grip builds that generate more lateral load than stock, the deflection is more significant and the geometry consequences more pronounced. The SPL RLBI E9X holds the arm position fixed under all load conditions; the geometry set at the alignment rack is the geometry the car runs during a corner, not the geometry after the rubber has been pushed through its deflection range.
What OEM part number does the SPL RLBI E9X replace? The SPL RLBI E9X replaces BMW OEM part number 33326770829, which is the factory rubber rear lower control arm inner bushing used across the E80 / E82 / E82M, E90-E93, and F80 / F82 / F83 / F87 platforms.
Why does SPL use the largest possible FK bearing in this location? A larger bearing distributes the same load over more contact surface area, which reduces specific loading on both the bearing and the housing, slows wear, and produces lower NVH than a smaller bearing handling the same forces. SPL specifically uses the largest possible bearing with the tightest fit FK offers at this location because the OEM bushing is large; using an undersized replacement bearing in an oversized housing would reduce the engineering benefit. The bearing size matches the scale of the load.
Should this bushing be replaced at the same time as the outer knuckle bushing? Ideally yes. Replacing the inner subframe bushing while leaving the outer knuckle connection in factory rubber keeps a deflection point that partially offsets the gains from the inner bushing upgrade. A complete rear lower arm spherical conversion addresses both the inner and the outer knuckle positions simultaneously for the full benefit.

About SPL Parts

SPL Parts is a USA-based manufacturer of high-performance suspension components engineered for both professional racing and demanding street applications. Built on the core principles of strength, lightweight construction, low friction, and precision, SPL Parts products deliver the adjustability and alignment performance required by top race teams and discerning enthusiasts alike. Every component is produced using USA-sourced, certified materials and machined by experienced local shops to exacting tolerances. Professional TIG welders ensure maximum weld integrity, while each part is hand-fitted and treated with anti-seize and 3M internal panel coating for lasting protection. SPL Parts conducts all research and development in-house, allowing the team to leverage firsthand product knowledge and deliver unmatched customer support. Their suspension components feature innovative adjuster designs for quicker, more precise alignments, and utilize spherical bearings with Teflon liners that are self-cleaning, self-lubricating, and built for long service life. From concept to assembly, SPL Parts is made with pride in the USA by skilled machinists and welders who are committed to quality, innovation, and performance.

Additional Information

The Bulletproof Automotive website contains many thousands of products purchased in multiple different currencies. All of the prices are entered manually and accurately at the time of entry. Due to the consistently fluctuating international exchange rates, at times prices may not be able to be honored at their original intended rate. We apologize for any inconvenience this may cause, unfortunately our website is unable to compensate dynamically for what can at times be volatile changes in the cost of items due to currency values fluctuating, changes in prices from suppliers, changes in shipping and import duties, and other factors. Rest assured that any order you place on line will be at zero risk to you in this area. If in the event your order cannot be fulfilled at the original intended website price we will offer you a 100% refund, no questions asked. We will continue to do our best to maintain updated prices and we will always continue to offer our price match guarantees as well to ensure our prices are always the best for you. In short, prices may change without notice. It is always advised to give us a call prior to placing your order online to confirm availability and to confirm current pricing.

Shipping Policy

Items that are in stock in the US, either at Bulletproof’s warehouse or at a supplier’s warehouse, are generally delivered within 7-10 days. Special order items from overseas take considerably longer. As a courtesy Bulletproof offers delivery estimates to our customers which take into consideration manufacturer availability and shipping schedule. These estimates represent our best guess based on previous orders from the manufacturer and do not in any way imply a guaranteed delivery window. Many manufacturers work in a “just in time” inventory system and often take 2-20+ weeks to produce an item once an order is submitted. All deliverable items are then sent to our Japanese warehouse. Bulletproof ships a minimum of one full ocean freight container every month from Japan, oftentimes more than one a month. Ocean freight takes an average of 4 weeks. Typically it breaks down to one week in Japan for paperwork and customs, two weeks by boat and one week in US customs/clearance. Due to the wide number of variables between manufacturer and shipping schedules, delivery estimates are simply just that – estimates. We attempt to estimate conservatively and we usually deliver faster than our estimates suggest. It is not Bulletproof’s policy to guarantee delivery time of any special order item, this is impossible for us to do. By ordering you acknowledge that there is no required delivery ETA and an order may not be canceled or altered due to manufacturing or shipping delays, all ETA’s are provided as a best guess only. Please review the full Terms & Conditions here.

BP Pricing Difference

We do pricing a little differently on our JDM brands and we believe in making things simple and clear. No hidden fees or surcharges. Every price you see includes the shipping cost to our office in Los Angeles, California and all the associated taxes/duties/fees for bringing the products into the US. The only shipping you ever pay is from our facility in the US to your location. Be wary of resellers that don’t include the cost of international shipping in their pricing on JDM parts. While we believe we’ll always have the lowest all-in price on JDM products, we offer a price match guarantee for all authentic parts purchased from authorized dealers as well. For many international customers, it’s much more affordable to ship from the USA than from Japan directly, as the air freight and ocean freight costs are typically much less. However, for customers looking to ship directly from Japan outside of North America, or domestically in Japan, we can provide pricing specifically for that scenario. Please do not hesitate to contact us with any pricing questions or concerns. Please email us at sales@bulletproofautomotive.com with any inquiries.

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SPL Parts Rear Lower Control Arm Inner Bushing for E8x / E9x / F8x BMW 1 & 3 Series / M2 / M3 / M4 [SPLRLBIE9X]

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SPL Parts Rear Lower Control Arm Inner Bushing for E8x / E9x / F8x BMW 1 & 3 Series / M2 / M3 / M4

Features

Specifications

Applications

Notes

Frequently Asked Questions

About SPL Parts

Reviews