UMI Performance 78-88 GM G-Body Non-Adjustable Tubular Rear Control Arm Kit - Red

Red Powder Coated Non-Adjustable Rear Four-Link Arms for the 1978-1988 GM G-Body

Four fabricated arms that replace the entire rear four-link on a G-Body, finished in bright red. Despite a working title that reads like front suspension, UMI sells this part as Rear Control Arm Kit, Non-Adjustable, and everything in the box mounts between the chassis and the rear axle housing.

Nothing in the kit threads or adjusts. Each arm is DOM tube with CNC machined ends and greaseable fluted polyurethane bushings pressed in at the factory, which is what makes it the quiet answer to wheel hop rather than the tunable one. The lower arms carry reinforced sway bar holes, and the whole set bolts in with the car's original control arm bolts.

Key Features

• Replaces all four rear control arms in one purchase.
• Lower arms in 1.500 inch DOM mild steel tube, upper arms in 1.625 inch, both 0.120 inch wall.
• TIG and MIG welded construction with CNC machined ends.
• Greaseable fluted polyurethane bushings with Zerk fittings at every joint, pressed in with their sleeves before shipping.
• Reinforced sway bar mounting holes in the lower arms for OEM and aftermarket rear bars.
• No rod ends anywhere, which is the fastest way to tell this kit apart from UMI's adjustable version.
• Grease pack supplied for bushing prep at assembly.
• Bolt-in with the factory hardware and no drilling.
• Bright red powder coat across all four arms.

Fitment

UMI publishes this kit for the 1978-1988 GM G-Body. UMI publishes year, make and model only for this part number and lists no submodel or trim breakdown, so the fitment tags on this listing stop at model rather than inventing a trim.

One documented inconsistency in UMI's own data: this product page lists the Oldsmobile Cutlass as 1981-1988, while UMI's 3011, 3028, 3034 and 3035 pages list the same platform as 1978-1988 and nothing in the engineering description changes by Cutlass model year. This listing publishes the 1978-1988 G-Body range that four other UMI pages agree on, and the conservative buyer-facing statement remains to confirm the year on a Cutlass build before ordering.

One shared-document caution: the cover of UMI's 3016 upper arm installation sheet also names the 1973-1977 GM A-Body, because the same upper arm is used on that platform. The 301516 kit itself is sold and listed by UMI as G-Body only, so no A-Body vehicles are tagged on this listing.

One colour caution worth knowing: a large retailer's index labels this R suffix part as black powder coated. UMI's colour naming and other retailers confirm the R suffix is red, and red is what ships against this part number.

Specifications

What's Included

• Two non-adjustable tubular rear lower control arms, part 3015, with polyurethane bushings and sleeves already pressed in
• Two non-adjustable tubular rear upper control arms, part 3016, with polyurethane bushings and sleeves already pressed in
• One installation instruction sheet and one grease pack with the lower arms
• One installation instruction sheet with the upper arms, plus the grease packet its procedure calls for
• All four arms finished in red powder coat

Mounting bolts are not included: UMI publishes hardware as not included for this kit and the factory rear control arm bolts are reused. The grease packet is genuinely in the box for this kit, which is a difference from UMI's adjustable 301417 kit, where no grease pack is documented.

About UMI Performance

UMI Performance builds chassis and suspension parts at 509 Hemlock Street in Philipsburg, Pennsylvania, using North American raw material from USA steel suppliers, machine-guided precision DOM tube bending, laser-cut plating and welds laid by skilled and robotic welders. Its rear suspension catalogue for these cars splits into adjustable and non-adjustable families. This is the non-adjustable family in red: fixed-length DOM arms, greaseable polyurethane throughout, and reinforced sway bar provision in the lowers.

Related Parts

• UMI 3028-B rear control arm reinforcement braces for 1978-1988 GM G-Body
• UMI 301417-R adjustable rear control arm kit for 1978-1988 GM G-Body
• UMI 3008 Super Lube synthetic grease for the greaseable polyurethane bushings

FAQ

The rear. The part is UMI's Rear Control Arm Kit, Non-Adjustable, and the four arms locate the rear axle housing. No part of this kit touches the front A-arms.

Because you want the car quiet and the geometry stock. This kit uses fixed-length arms and polyurethane at every joint, so there is no rod end noise and nothing to re-check after a season of driving. The adjustable kit exists for builders who need to set pinion angle or square the axle, and it accepts more noise in exchange for that control.

Yes. The lower arms have reinforced sway bar holes and UMI states they work with OEM and aftermarket bars. Unbolt the bar from the lower arms at the start of the job and refit it before the car comes down.

No. UMI lists hardware as not included and the kit is designed around the factory 18 mm control arm bolts. Inspect those bolts as they come out; anything stretched, badly corroded or previously over-torqued should be replaced with a correct-grade fastener.

UMI publishes 72 ft-lb for both the lower and the upper control arm bolts, applied with the weight of the vehicle on the rear axle. Suspension position matters a great deal on a polyurethane bushing: clamping the bushing at full droop leaves it permanently twisted at ride height.

At assembly, coat the outside of every bushing heavily with the supplied Energy Suspension grease. In service, UMI calls for 1 to 1.5 pumps per fitting on the lower arms and 2 to 3 pumps per fitting on the uppers. Orient the lower zerks toward the ground and the upper zerks toward the floor board so they stay reachable.

Expect more feedback than a car on collapsed rubber, and expect the axle to stay where you put it under power. Squeak comes from a dry polyurethane bushing, not from the material itself, which is exactly why these are fluted, greaseable and shipped with a grease pack.

No. The arms are fixed at factory length, which restores stock pinion geometry. If the car is significantly lowered or running a non-stock housing and needs pinion angle tuned, the adjustable 301417 kit is the correct part.

No. UMI's kit page shows a single 1.625 inch figure, but that is the upper arm. The lower arms are 1.500 inch outside diameter. Both use a 0.120 inch wall in DOM mild steel.

Not at all. B and R denote powder coat colour only, and the tube sizes, welds, bushings, sleeves and grease pack are the same on both.

They are designed around the factory G-Body housing. A swapped housing can change control arm mount spacing and effective arm length, so measure against stock before ordering if the rear end is not original.

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, exceeding the design limits of the product, improper installation, altered product, non-UMI components, 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. Note that the printed sheet in the box still carries an older, narrower disclaimer that predates the current two year term. The policy page is the current document. Neither is a Black Ops Auto Works warranty.

Installation Instructions

1. Raise and safely support the rear of the vehicle, then unbolt the rear sway bar from the lower control arms.
2. Work one side of the car at a time and change a single arm at a time so the axle housing stays located. The original control arm fasteners take an 18 mm socket.
3. Coat the outer surface of each polyurethane bushing heavily with the supplied Energy Suspension grease before the arm is offered up.
4. Fit each lower arm with its grease fitting aimed toward the ground.
5. Fit each upper arm with its grease fitting aimed up toward the floor board.
6. Reattach the rear sway bar to the reinforced holes in the lower arms.
7. Set the car down so its weight rests on the rear axle before anything is fully tightened.
8. Torque both the lower and the upper control arm bolts to UMI's published 72 ft-lb.
9. Charge each fitting with grease: 1 to 1.5 pumps on the lowers, 2 to 3 pumps on the uppers.
10. Re-check torque after the first drive, then keep the fittings serviced as part of routine maintenance.

72 ft-lb is UMI's published figure for these arms. For any fastener UMI does not cover, use the General Motors factory service information for your exact year and model rather than a generic value.