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Rod End Adjustable Rear Lower Control Arms for the 1978-1996 GM B-Body
This pair of rear lower control arms suits a 1978-1996 GM B-Body, including the 1994-1996 Chevrolet Impala SS and the 1978-1996 Chevrolet Caprice, where bind-free rear axle articulation matters more than isolation. The axle end uses a chrome-moly Teflon lined spherical rod end, while the chassis end bolts up on a polyurethane bushing.
That mixed configuration is the single difference that separates this part number from UMI's all-polyurethane B-Body lower arm. Everything else matches: 5/8 inch of added length with a further 1/4 inch of adjustment, 1.500 inch DOM tubing, full TIG welding, a 0.120 inch sway bar sleeve and a billet aluminium sway bar spacer.
Key Features
- Chrome-moly Teflon lined spherical rod end at the rear axle housing for bind-free articulation
- Polyurethane bushed end that bolts to the chassis
- Extended 5/8 inch over factory with a further 1/4 inch of adjustment
- 1.500 inch DOM tubing, fully TIG welded
- Sway bar provision reinforced with a 0.120 inch sleeve plus a billet aluminium spacer
- Ships fully assembled with greaseable Energy Suspension bushings
- New 10.9 grade sway bar hardware included and a direct bolt-on fit
Fitment
| Vehicle | Years |
|---|---|
| Buick Roadmaster | 1991-1996 |
| Buick LeSabre | 1978-1985 |
| Chevrolet Caprice | 1978-1996 |
| Chevrolet Impala SS | 1994-1996 |
| Pontiac Bonneville | 1977-1981 |
| Pontiac Catalina | 1977-1981 |
The packaged instruction sheet is headed 1991-1996 GM Impala SS, and older catalogue copy repeats that range. UMI's live application table lists the Impala SS itself as 1994-1996 within a 1978-1996 B-Body platform, so the 1991-1996 wording is B-Body generation shorthand rather than an Impala SS fitment range. The years published here follow the manufacturer application table.
UMI publishes year, make and model for this part number without a submodel, trim, engine or drivetrain breakdown, so the fitment tags on this listing stop at model level rather than inventing a trim. The one exception is the Impala SS, which UMI names directly.
Specifications
| Detail | Value |
|---|---|
| Position | Rear lower, sold as a set of two arms |
| Axle side joint | Chrome-moly Teflon lined spherical rod end |
| Chassis side joint | Polyurethane bushed end |
| Length versus factory | Extended 5/8 inch, plus 1/4 inch of additional adjustment |
| Tubing and welds | 1.500 inch DOM, fully TIG welded |
| Sway bar provision | 0.120 inch reinforcing sleeve with a billet aluminium sway bar spacer |
| Assembly | Ships fully assembled with greaseable Energy Suspension bushings |
| Material and style | Mild steel, tubular |
| Finish | Powder coat, black on this part number |
| Mounting hardware | Not included. Factory bolts are reused, and new 10.9 grade sway bar hardware is supplied |
| Modifications required | None. Direct bolt-on |
| Recommended torque | 72 ft-lb on the lower control arms, and as much as 90 ft-lb only if a clunking noise is present after installation |
| Ride quality expectation | A spherical rod end passes more road feel and driveline noise into the body than a rubber or polyurethane joint. UMI publishes no measured noise figure for this part number |
| Shipping weight and boxed dimensions | Recorded by UMI as not available |
| Country of manufacture | United States. UMI manufactures in Philipsburg, Pennsylvania |
| Manufacturer warranty | Two years from the original date of purchase against defects in materials and workmanship, to the original purchaser only and not transferable |
| Warranty exclusions | Misuse, abuse, neglect or accident, use beyond the design limits of the product, improper installation, acts of God, handling and shipping damage, any product altered, adjusted, tampered with or defaced, non-UMI components, incidental costs such as towing and labour, and normal wear items including bearings and bushings |
| Warranty document conflict | The packaged instruction sheet still carries an older all-caps disclaimer limiting coverage to freedom from defect at the time of purchase. UMI's live policies page publishes the current two year term and is the document summarised here. Neither is a Black Ops Auto Works warranty |
| Third-party component compatibility | UMI states it cannot guarantee compatibility or performance of its products with other components used alongside them, so confirm dimensions before mixing brands |
| Suitability versus warranty | UMI builds this arm for B-Body cars where the rear suspension needs to articulate without bind, typically street and strip use with a corrected thrust angle. That describes what the part is built to do. Warranty eligibility is separate: UMI covers defects in materials and workmanship for two years and excludes damage from exceeding the design limits of the part, improper installation, and normal wear on bushings and bearings |
What's Included
- Two adjustable extended length rear lower control arms, assembled, with a rod end on the axle side and a greaseable polyurethane bushing on the chassis side
- New 10.9 grade sway bar hardware
- Energy Suspension grease packet
- One installation instruction sheet
The shared instruction sheet lists one installation sheet and the grease packet. Itemised fastener counts are not published by UMI for this part number and none are invented here.
About UMI Performance
UMI Performance builds chassis and suspension parts at 509 Hemlock Street in Philipsburg, Pennsylvania, using precision bent DOM tubing, laser cut steel, TIG and robotic welding and durable powder coat finishes. The rod end B-Body lower arm sits alongside UMI's polyurethane version in the same full-size GM programme, giving buyers a choice between isolation and articulation.
Related Parts
FAQ
What is the difference between this arm and the all-polyurethane version?This part number uses a Teflon lined spherical rod end at the axle for bind-free articulation. The other B-Body lower arm uses polyurethane at both ends for more isolation.
Which end mounts to the chassis?The polyurethane bushed end bolts to the chassis. The rod end goes on the rear axle housing.
How much adjustment is available?The arms are 5/8 inch longer than factory as delivered, with 1/4 inch of further adjustment at the threaded adapters.
Do they arrive assembled?Yes. UMI ships them fully assembled with the greaseable Energy Suspension bushings already fitted.
What torque should I use?72 ft-lb on the lower control arms with the suspension loaded, and up to 90 ft-lb only if a clunk shows up after installation.
Is mounting hardware included?No. The factory bolts are reused, and new 10.9 grade sway bar hardware is supplied.
Will the rod end make the car noisier?A spherical joint transmits more road and driveline feel by design. UMI publishes no measured noise figure, so expect more feedback than a bushed arm and treat rod end wear as a maintenance item rather than a warranty claim.
Does it fit a Caprice as well as an Impala SS?Yes. UMI lists the 1978-1996 Chevrolet Caprice in the same application as the 1994-1996 Impala SS for this part number.
How do I set thrust angle?Loosen the bushing at the axle side, loosen the jam nut, adjust the length, then retighten the jam nut and the mounting bolts with the suspension loaded.
What warranty applies, and what is excluded from it?UMI publishes a two year warranty from the original date of purchase against defects in materials and workmanship, to the original purchaser only, and it is not transferable. The same policy excludes misuse, use beyond the design limits of the part, improper installation, acts of God, handling and shipping damage, any product that has been altered, adjusted, tampered with or defaced, components not made by UMI, incidental costs such as towing and labour, and normal wear items including bearings and bushings. UMI also states it cannot guarantee compatibility with other manufacturers' components. The sheet packed in the box still carries an older disclaimer that predates the current two year term, and the live policy page is the document that governs. Neither is a Black Ops Auto Works warranty.
Installation Instructions
- Support the rear of the car on two jack stands under the frame rather than under the axle.
- Remove the sway bar from the lower arms.
- Work one side at a time and remove the front and rear control arm bolts on that side.
- Pre-lube the polyurethane bushing surfaces with the supplied grease packet.
- Fit the new arm with the rod end at the axle housing, the polyurethane end at the chassis, and the grease fittings angled toward the ground.
- Repeat on the opposite side, then reinstall the sway bar after greasing the arm.
- Move the jack stands under the rear axle so the suspension is loaded.
- Tighten all four mounting bolts to 72 ft-lb, going to 90 ft-lb only to cure a clunk.
- Adjust thrust angle at the jam nut if required, then recheck all fasteners.
UMI publishes one installation sheet covering both B-Body lower arm part numbers at https://static.speedwaymotors.com/pdf/1853614B.pdf.
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