The past few orders I have placed with Rock Auto have been more hassle than ordering parts should ever be. I've received wrong/defective parts on several occasions and have spent more time on the phone with them than I ever care to. To their credit, they handled a couple of situations well, but recently they've really burned me.
First situation was a big order of parts for the engine I'm building for my van. I'm leaving the balance shafts on and decided to replace the balance shaft tensioners and chain. The chain I received from them had the correct part number on the box. The engine was still at the machine shop, I was just preparing for the assembly. When I assembled the bottom end, the chain they sent was way too long. Long story short, they wouldn't replace the chain. We got into a little dispute on how to count chain links, regardless, the chain they sent is twice as long as the stock chain on a 2.5. They decided I somehow ordered the wrong part???? Even though the box had the part number on it for an 89 plymouth voyager 2.5 turbo. So I have a new chain I can't use, and the original chain is back on my engine.
Second Situation, I ordered 2 fan clutches for a mazda RX-7. One for my car, one for my buddy's car. Both fan clutch boxes had the correct part number. I was out of town for work when the box came in, my buddy installed one of the fan clutches on his car and it worked great, solved all his problems. Between work/ rebuilding a differential in one of my other cars/ dealing with the insurance company due to someone rear-ending me in another car/ etc. a couple months passed. The fan clutches were closeout parts with a 30 day warranty. After rebuilding the turbo on my car, doing some ceramic coating, and some suspension work, I went to install the fan clutch. Only to discover that the part was wrong. It was in the right box with the correct part number, but wouldn't fit on my car. I called Rock auto, and the shipped me a new one free of charge (great!). I received the replacement part, which was correct, but defective. My car overheats at idle with the new part. I called rock auto and told them this fan was defective, they won't cover it. So I'm out $70, and I still don't have the right part.
3rd situation, I don't even want to call them for this one. At this point I can't even believe it myself. I get more defective/wrong parts than I do correct ones. I ordered a A/C mode actuator for a 2000 envoy. Part is defective. Plug their part in, does nothing. Plug in original it moves. I give up, I don't think I can get on the phone with them again.
All this to say beware ordering from these guys, you might get wrong/defective parts and be stuck with them. I think I'm done doing business with them, which saddens me. I used to think they were pretty great. I never thought getting correct/working parts could be such a hassle.