LetterAgent
Mail physical letters by just asking your AI assistant.
Home > Guides > Shipping car parts
Small car parts ship fine in a sturdy box with heavy padding, as long as you drain every drop of oil, coolant, or fuel first and bag the part against leaks. Heavy parts like engines and transmissions do not go in a box: they travel as freight, strapped to a pallet. Carriers treat residual fluids as hazardous material, and a leaking box gets pulled out of the network fast.
| Part | Best method | Key requirement |
|---|---|---|
| Small parts (sensors, mirrors, trim) | Padded box | Wrap sharp edges, fill all voids |
| Heavy parts (rotors, calipers, alternators) | Heavy-duty or double box | A single-wall box will not survive |
| Body panels (fenders, bumpers) | Oversized box or custom crate | Protect mounting tabs and edges |
| Tires | Banded together, no box needed | Confirm your carrier accepts unlabeled tires |
| Engines, transmissions | Freight on a pallet | Fully drained, ports plugged, strapped down |
Drain first, pack second. Any part that ever held fluid gets drained completely, then sealed in a heavy plastic bag as leak insurance. Cover sharp edges and mounting flanges with cardboard so they do not cut through the box from inside. A brake rotor will punch straight through a single-wall box, so heavy small parts get a heavy-duty or double box with padding on all six sides. Fill every void: a part that can shift can build enough momentum to break its own packaging.
These ship as freight, not parcels. The engine gets fully drained of oil and coolant, all ports get plugged, and it gets bolted or strapped to a pallet or crated. Most people book this through a freight broker rather than calling a carrier directly, because brokers consolidate loads and the price difference is real. Measure the palletized dimensions carefully: freight is priced on size and weight, and a pallet that does not match its booking gets re-rated. This is also the one category where a photo record before pickup pays off, since freight claims are paperwork-heavy.
Fluids are the big one: carriers reject anything still wet with oil, fuel, or coolant, and a leak discovered in transit can get your whole shipment quarantined. Batteries and airbags are regulated as hazardous materials and need hazmat-compliant packaging and labeling: this is not a DIY category. Used catalytic converters attract extra scrutiny because of theft and recycling regulations. And tires surprise people in the good way: several carriers accept banded tires with a shipping label stuck on, no box required, though you should confirm the policy with your carrier first rather than assuming.
Ready to ship it? Get a shipping label with LetterAgent: describe it to your AI assistant, approve the exact quoted price, and get your label.
LetterAgent is a working name. Prices include print, postage, and our service fee. US prices in USD, Canadian prices in CAD (Canadian prices exclude applicable sales tax, added at checkout). Currently in private testing.
Need help? Ask your assistant: it can check a job's status any time. If it ever can't handle something: hello@getletteragent.com