You can find good free photos on websites like Pexels Pixabay, and Unsplash. Try searching things like “mechanic under car,” “gearbox,” or “transmission repair.” Pexels usually has the most realistic shop shots.
If you ever need more specific ones, Depositphotos and Adobe Stock have decent single-image pricing without locking into a subscription.
Also, don’t underestimate your own phone. Take a few shots in good lighting .maybe a tech working on a transmission, close-ups of tools, or a clean bench setup. Then use a free app like Snapseed to brighten and sharpen them.