I’ve got 77K miles on this truck. It runs fine except for a squeal under the hood for the last 35K miles. When it first came up I sprayed it with belt treatment. no difference. At 50K the dealer replaced the serpentine belt. No difference. At 60K a different dealer tried to lube it. No difference. At the 75K maintenance, the dealer told me the above parts should be replaced for $788, but it was not a critical repair. Am I getting sold a bill of goods here? Is the price fair?
I had this same problem with a 2003 Toyota 4Runner which occured right after the delivery as a new car. The dealer changed the belt three times and the squeak was still there. On one replacement, the belt was not installed correctly and it pulled out the oil seal behind the crankshaft pulley. I finally told the dealer politely, but firmly, that he had one more chance to make it right or he could buy the car back under the lemon law. The problem was traced to a defective tensioner. A new belt and tensioner corrected the problem. I have not returned to the dealer since that time.
I think the price you have been quoted is high. If you have a good independent garage in your area, I would get a price from them.