* Engine Options: GMC 2500s in 1985 came with a variety of engine options (V6, V8, diesel). The transmission choice depended on the engine.
* Transmission Types: Common transmissions for this era include:
* TH400 (3-speed automatic): Popular for heavy-duty applications.
* TH700-R4 (4-speed automatic): More fuel-efficient, offered with some engines.
* SM465 (4-speed manual): A strong, robust manual transmission.
* NV4500 (5-speed manual): Introduced later in the 1980s, may be present in some late-model 1985 trucks.
To determine the transmission in your specific truck, you'll need to:
1. Check the VIN (Vehicle Identification Number): The VIN contains information about the truck's build. You can use a VIN decoder online to find the transmission code.
2. Look for a tag on the transmission: The transmission itself may have a tag that identifies it.
3. Check the owner's manual: If you have the original owner's manual, it should list the transmission type.
4. Consult with a mechanic: A mechanic can easily inspect the truck and identify the transmission.