How US Truck Parts Direct is built
Every fact here was read from a manufacturer's own published document and carries a link back to it. This page explains where the data comes from, what the trust labels mean, how the data is audited, and what is deliberately missing.
Where the data comes from
The database behind this site is assembled from documents that manufacturers publish themselves: application catalogues, cross-reference tools, product pages and technical specification sheets. 5,017 such documents are cited across the site, published by 7 manufacturers.
Nothing is taken from forums, from third-party cross-reference compilations, or from anywhere behind a login. Where a manufacturer's terms prohibit automated access, or where a site refuses our crawler, we record that and leave the source alone — which is why some brands you might expect are absent.
Every claim is citable
Each row in the database stores the document it came from, the page or table location within that document, and a short excerpt of the text that supports it. The site shows the document and the location under Sources on every page. There are 202,040 such citations behind the 5,881 pages here, and no page is published without at least two of them.
What the labels mean
| Label | What it means |
|---|---|
| Verified | Stated by the manufacturer's own published cross-reference or catalogue — the strongest evidence available short of a physical fit check. |
| Single source | One publisher states it and nothing contradicts it. Usually correct; not corroborated. |
| Seller-claimed | A seller's listing asserts it and no manufacturer document confirms it. Treat as a lead, not a fact. |
| Inherited | Copied from a part confirmed equivalent to this one, because this part's own manufacturer publishes no value. Shown for context; never counted as this part's own specification. |
Where two publishers disagree, neither value is shown and the conflict goes to a review queue instead.
Units are never assumed
Some manufacturers print a dimension as a bare number. Where that happens the number appears here exactly as published, with a note that the source states no unit. Guessing inches or millimetres from the magnitude would be a plausible-looking error, and a wrong dimension on a part someone is about to fit is the failure this whole project exists to avoid.
How the data is audited
Extraction is checked by re-reading the original documents in a fresh context — a separate pass that has not seen how the data was pulled — and scoring a random sample against the source. Results so far:
| Audit | Sample | Correct |
|---|---|---|
| Cross-references (Luber-finer catalogue) | 30 facts | 30 of 30 correct |
| Cross-references (Grote and Webb) | 30 facts | 30 of 30 correct |
| Fitment (Luber-finer catalogue) | 40 facts | 40 of 40 correct |
| Specifications (four extractors) | 80 facts | 80 of 80 correct |
The thresholds are 97% for cross-references and specifications and 95% for fitment. When a sample falls below its threshold, that extractor stops publishing until the cause is found and the affected data is reloaded — which has happened, and is why some pages were rebuilt.
What is missing, and why
- Prices and sellers. No page shows a price or a place to buy. The routes to trustworthy public pricing either need an approved API or a retailer's permission, and none is in place yet. An invented or stale price would be worse than none.
- Photographs. Product photographs belong to the manufacturer who made them. Where a manufacturer's published terms expressly forbid reproducing site material, no image of theirs appears here, even though we cite their data. Where the terms are silent, the manufacturer's own product photograph is shown, credited, unaltered, and with the source page linked; any manufacturer that objects can have its images removed on request. Some manufacturers publish only small thumbnails, which is why some photographs are small.
- Coverage. This is a deliberately small, deep set of 5,881 pages rather than a thin catalogue of everything. Parts without enough evidence to be useful are not published at all.
Citing this site, and reading it by machine
You may quote and cite any fact here; please link to the part page, which in turn links to the manufacturer document. AI assistants and answer engines are welcome: nothing here is behind a login or a script, every page has structured data, and the robots file says so explicitly.
- /llms.txt — a plain-text guide to the site for language models, with the key pages.
- /llms-full.txt — one line per part page: manufacturer, number, what it is, URL.
- Any part page plus
index.json— the same facts as JSON: specifications, fitment, cross-references with their evidence labels, and the cited sources. - /sitemap.xml — every page, with last-modified dates.
Facts (part numbers, relationships, measurements) are not copyrightable and may be reused; the manufacturers' photographs remain theirs.
Reporting an error
If something here is wrong, the citation on the page tells you exactly which document was read and where. That makes a correction quick to verify. Send the page URL and what is wrong with it to the contact address on the repository, and if it is our reading error it is fixed at the source and the page rebuilds.