Figuring Out Big Tex Trailer Parts Diagrams Without Losing Your Mind
Parts diagrams for Big Tex trailers aren't as straightforward as they should be, and if you've spent any time looking for one, you already know that. The company publishes them, but the process of finding and actually using them is something else entirely. I deal with this stuff regularly and I still waste more time than I'd like admitting. The official route starts at bigtextrailers.com. They have a parts section, but it's not obvious where it lives on the page. You'll need your trailer's serial number or model number before anything else works. The lookup tool on their site won't give you anything without a valid VIN or serial. I've had people show up asking for diagrams and they don't even know their trailer's model number, which is a problem since Big Tex doesn't organize their diagrams the way you'd expect. Third-party sites like trailerpartsexpress and etrailer.com also carry Big Tex diagrams. Sometimes they're more useful because they cross-reference parts across different model years, which the official site doesn't always do well. I use etrailer as my secondary check when the Big Tex site is being unhelpful, which is often.
The serial number location matters more than people realize. On most Big Tex utility trailers, it's stamped on the left side of the tongue, near the coupler. On their landscape trailers, it can be on the frame rail near the axle. If you can't find it, the diagram won't load properly.
The Practical Problems You're Going to Hit
The biggest issue with Big Tex Trailer Parts Diagrams is that they're not always consistent between model years. A 2018 Big Tex 10TS and a 2022 10TS might share the same model name, but the bracketry, weld patterns, and hardware can differ enough that a diagram from one year won't map cleanly onto the other. I ran into this last fall working on a customer's 2019 Big Tex 83X with a failed swing-out spare tire mount. The diagram showed part number 8800-046-00 for the bracket assembly, but the actual trailer had a slightly different mounting flange that wasn't listed anywhere in that exploded view. I ended up measuring the bolt pattern, comparing it against a 2021 diagram for a similar model, and ordering the newer version which was backward compatible. The diagram didn't tell me that, but the physical evidence did. Another thing nobody warns you about: many Big Tex diagrams are what I'd call "functional" rather than "complete." They show the major assemblies and the parts that most commonly fail, but fasteners, washers, and minor brackets often get grouped under generic part numbers or omitted entirely. If you're trying to rebuild something down to the last bolt, you're going to be frustrated. I've had to source individual flat washers and hex nuts from McMaster-Carr because the diagram just listed them as part of a larger kit without breaking them out separately.
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Working Around the Inconsistencies
My approach is to print the diagram, photograph the area of the trailer I'm working on, and overlay the two visually. This sounds tedious but it saves about twenty minutes per part lookup compared to guessing from the diagram alone. The overlay step catches mismatches early, especially with suspension components and tongue assemblies where Big Tex has made undocumented changes between production runs. If the diagram you find online is low resolution or the part numbers are blurry, take the trailer to a well-lit area and photograph the actual part plate or stamping. Big Tex parts often have their own individual part numbers stamped or tagged on them, and those tend to be more reliable than what appears in the documentation. I keep a digital folder of these photos organized by trailer model and year, and it's cut my parts identification time down to maybe five minutes for most common components instead of the usual twenty or thirty.
When Diagrams Won't Help You
Let me be clear about where this falls apart. If you're dealing with a customized or modified Big Tex trailer—something with aftermarket fenders, a winch platform, or a non-stock coupler—the published diagrams are basically useless. Big Tex doesn't document third-party modifications, and their diagrams only reflect factory configurations. I've had a couple customers bring in trailers with homemade cargo ties or relocated jack stands and the diagrams had zero relevance to what they were actually trying to replace. For older trailers, pre-2015 models specifically, the online diagrams are spotty. Some of those are still available as PDFs through dealers, but they're not searchable and the image quality is poor. If you're working on one of those, your best bet is contacting a Big Tex authorized dealer directly and asking them to pull the diagram from their internal systems. It takes longer but it's often the only way to get a clean copy for older models. The diagrams themselves are generally accurate for what they cover. The limitations are real but manageable if you know where to look and what to expect. Take the time to locate your serial number correctly, don't assume year-to-year consistency, and keep a camera handy on the trailer when you're doing parts work. That's about all there is to it.
