Serpentine Belt BS
 

My in-laws Subaru threw the serpentine belt and it got wrapped around the ac pump. Dealership it was towed to refuses to simply replace the belt and wants to replace all the pulleys and idlers. In-laws already confirmed all pulleys and idlers spin by hand, idler spring works, engine starts, and removed the belt and other debris themselves. Is there any way the dealer isn't full of it saying the extra work needs to be done?

You have to discover why it threw the belt in the first place. Just because your in-laws can spin the pulleys and the spring has some tension doesn't mean there isn't a problem with one or more of them. How many miles on the car? Was all the services done per the book or only the basics when needed?
I'm not criticizing, just asking so you/they can make an informed determination. You replace all the spark plugs when you change them, not just a couple which look bad. Same goes for pulleys etc. especially if it’s a higher mileage vehicle.

I swapped out all of my idlers and tensioner when I did the S belt service. They all spun freely but two of the idlers hummed pretty loudly indicated bad bearings. The tensioner I just did preemptively as 80% + of the time the car only sees track use.

Welp, they could just replace the belt, put it back together and see how it looks and sounds - maybe they will get lucky.

:iono:

Yeah it's got like 120k on it and my FIL can replace the pulleys himself. It probably went because the belt is 18 years old. Both of us understand there is more follow up to do.

The problem is the dealership refuses to just replace the belt and let him drive it home to do the rest of the work himself. They won't even explain why, other than "the technician said it has to be done".

Yes, but they also apparently want to swap out the crank pulley and maybe other stuff. Which sounds really weird.

Even if the idlers aren't in great shape, it should be fine to drive the 30 miles to his house.

Back in the day, when I had less money than I now do, I would have purchased a belt from the parts department, tell the dealer to give me the keys to my car, drove it off the lot, parked it on the street, replaced the belt and driven it home.

:iono:

That's basically what is happening as soon as the dealer gets the belt, which is apparently taking a week to get there.

You are more polite than me. I would do it right in their parking lot. If they can’t tell me a reason something needs done they can pound sand.

I have never heard of a crank pully going bad.

But, if they do - they are a bitch to replace - :confused0068:

Maybe go to the parts department in a bigger garage?

:iono:

I had the crank pulley on my son's 05 Forester go bad. The outer ring started slipping when the ac was on. It looked fine. I replaced the belt and was getting ready to replace the compressor when someone more knowledgeable than myself pointed out the problem.

I've replaced belts alone on good faith to save the customer money but as they say, no good deed goes unpunished. Nowadays I immediately specify tensioner and idler pulleys be replaced with the belt. Better to do the job once. Tows aren't cheap