UMI Performance Adjustable Rear Upper Control Arms - Roto-Joint - Black (1978-1996 GM B-Body) (3628-B)
Eliminate rear axle deflection, prevent wheel hop, and simplify pinion angle adjustment with the UMI Performance "On-Car" Double Adjustable Rear Upper Control Arms featuring Roto-Joints (3628-B). Specially designed for standard-length application on 1978-1996 GM B-Body platforms—including the Chevrolet Impala SS, Caprice, Buick Roadmaster, and LeSabre—these heavy-duty upper control arms provide the strength and adjustability required for street performance, drag racing, and pro-touring applications.
Constructed from 1/4" thick CNC laser-cut mild steel mounting pads with heavy-duty DOM tubing, these arms feature 4140 chromoly threaded tube adapters and a heat-treated 4140 chromoly turnbuckle adjuster. This double-adjustable design allows effortless on-car pinion angle tuning without unbolting the arm from the vehicle chassis or axle housing. Outfitted with UMI's rebuildable spherical Roto-Joints featuring self-lubricating Delrin races, they deliver 28 degrees of bind-free articulation while damping road noise, vibration, and harshness. Finished in a durable gloss black powder coat and designed as a direct bolt-in replacement for all factory and aftermarket rear axle housings.
Features
- Standard OEM length adjustable upper control arms replace flex-prone factory stamped steel arms
- On-car double-adjustable design uses a heat-treated 4140 chromoly adjuster for easy pinion angle tuning
- Features UMI rebuildable spherical Roto-Joints with 28 degrees of total rotation for bind-free suspension movement
- Self-lubricating Delrin races in Roto-Joints absorb road shock and vibration for a quiet street ride
- Heavy-duty 1/4" thick CNC laser-cut mounting pads with precision TIG and MIG welding
- High-strength 4140 chromoly threaded tube adapters for superior thread durability
- Direct bolt-in installation using basic hand tools in approximately 1-2 hours
- Durable gloss black powder coat finish protects against rust, corrosion, and road debris
- 100% designed, tested, and manufactured in Philipsburg, PA – USA
Specifications
- SKU: 3628-B
- Manufacturer: UMI Performance
- Country of Origin: USA (Philipsburg, PA)
- Mounting Pads: 1/4" Thick CNC Laser-Cut Mild Steel
- Adapters & Adjuster: Heat-Treated 4140 Chromoly Steel
- Bushings/Joints: Rebuildable Spherical Roto-Joints w/ Delrin Races
- Adjustability: On-Car Double Adjustable (Chromoly Adjuster)
- Control Arm Style: Standard Length Adjustable
- Finish: Gloss Black Powder Coat
- Installation Time: 1-2 Hours
- Unit of Measure: Pair (Driver & Passenger Side)
- Hardware: Uses OEM Frame Hardware
Fitment Notes
- Position: Rear Upper Control Arms (Pair).
- Fits 1978-1996 GM B-Body platforms (Chevrolet Impala SS, Caprice, Buick Roadmaster, LeSabre, Pontiac Bonneville, Catalina).
- Standard OEM length arms; designed for use with standard-length lower control arms.
- Compatible with factory stock and all aftermarket rear end housings.
- Direct bolt-in upgrade; reuses factory frame and axle housing bolts.
Fitment
1991 Buick Roadmaster
1992 Buick Roadmaster
1993 Buick Roadmaster
1994 Buick Roadmaster
1995 Buick Roadmaster
1996 Buick Roadmaster
1978 Buick LeSabre
1979 Buick LeSabre
1980 Buick LeSabre
1981 Buick LeSabre
1982 Buick LeSabre
1983 Buick LeSabre
1984 Buick LeSabre
1985 Buick LeSabre
1978 Chevrolet Caprice
1979 Chevrolet Caprice
1980 Chevrolet Caprice
1981 Chevrolet Caprice
1982 Chevrolet Caprice
1983 Chevrolet Caprice
1984 Chevrolet Caprice
1985 Chevrolet Caprice
1986 Chevrolet Caprice
1987 Chevrolet Caprice
1988 Chevrolet Caprice
1989 Chevrolet Caprice
1990 Chevrolet Caprice
1991 Chevrolet Caprice
1992 Chevrolet Caprice
1993 Chevrolet Caprice
1994 Chevrolet Caprice
1995 Chevrolet Caprice
1996 Chevrolet Caprice
1994 Chevrolet Impala SS
1995 Chevrolet Impala SS
1996 Chevrolet Impala SS
1977 Pontiac Bonneville
1978 Pontiac Bonneville
1979 Pontiac Bonneville
1980 Pontiac Bonneville
1981 Pontiac Bonneville
1977 Pontiac Catalina
1978 Pontiac Catalina
1979 Pontiac Catalina
1980 Pontiac Catalina
1981 Pontiac Catalina
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