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Does your hood shake at idle and rattle over every bump? The hinges usually get blamed first — and they are usually fine. The real culprit is the small rubber bumper the hood rests on when it is closed. Years of weight have flattened it.

The fix is cheap and quick: about 30 minutes with hand tools, no hood removal. The hood rest bushing channel assembly covers eight Peterbilt models, from the 379 (1987-2007) to the 389 (2007-2024). It restores the support the hood was designed around.

Why a flat bushing shakes the hood

The hood is a big fiberglass shell — roughly a quarter ton. The rear hinges carry the weight, but the front just rests on a small rubber bumper. That bumper sets the gap and holds the hood still.

Rubber squeezed for years goes flat and stays flat. Mechanics call this compression set: the rubber never springs back. A gap opens at the front, and now every idle pulse rocks the hood.

Ignore it and the damage grows. The hood lands on bare metal, the paint wears through, rust starts, and the fiberglass cracks. A $25 bushing turns into a body repair.

The 5-minute finger test

Not sure it is the bushing? Run this check with the hood closed:

• Press down on the front of the hood and let go. A good bushing rebounds silently. A flat one clacks.
• Slide a finger under the front lip. Feel for a hard, glossy, flattened band — that is worn rubber.
• Compare the left and right rest points. If one feels different, it is worn.
• Look for oil or grease on the rubber. Petroleum products eat this material.

One more clue: shake that is worst on a cold morning and softens as the truck warms up. Flat rubber is stiffest when cold.

Which part fits your truck

Peterbilt's own number for this bumper is 13-04711. The aftermarket cross-references it openly — Atro lists HM75-65711 as the same part. So pick by construction and warranty, not by the number on the box.

Both sides wearing out together is the normal case — they carry the same load. That is why the two-piece set exists. Bumper parts, hood hardware and trim for the same trucks live in the exterior parts collection.

Rest bumper or pivot bushing? Do not order the wrong part

This is the most common ordering mistake on these trucks, and it costs a wasted teardown. The two parts sound similar but live in different places:

• Hood shakes while closed → rest bumper (13-04711), the part in this guide.
• Hood flops while tilting → rear pivot bushings — a different part family, e.g. OEM 13-04588 on the 386 (2006-2015).

Replaced the rest bumper and the hood still rocks? Then the play has moved into the hinge holes and hardware. Diagnose by location before you order.

How to replace it: about 30 minutes

1. Park on level ground with the hood closed and supported so it cannot drop.
2. Unbolt the worn bushing or channel from its mount.
3. Clean the mounting surface. Scrape off rubber residue and rust — corrosion left under the new part restarts the wear.
4. Set the new unit in place. On the channel assembly, align the track first, then seat the bushings.
5. Torque evenly and close the hood. You want rubber compression everywhere, no metal contact, and the header panel level with the fenders.

No programming, no fluids, no calibration. If a fresh squeak shows up weeks later, the channel was under-torqued or misaligned — recheck the bolts.

Seeing dash warnings at the same time? A sensor fault can ride along with the shake, and this pressure sensor for Peterbilt, Freightliner, Kenworth and more is worth ruling out. On camera-equipped trucks, hood work also raises the calibration question — see the ADAS calibration troubleshooting guide.

Frequently asked questions