Have just had my 2007 Prius MOT'd (compulsory annual check in the UK for cars over 3 years old). It passed, but with the following advisory information: 1. Subframe mounting prescribed area is corroded but not considered excessive nearside rear [2.4.A.3] 2. Subframe mounting prescribed area is corroded but not considered excessive offside rear [2.4.A.3] 3. Suspension arm corroded but not seriously weakened nearside front [2.4.G.1] 4. Suspension arm corroded but not seriously weakened offside front [2.4.G.1] Tester says nothing to worry about. Not sure why this has suddenly appeared this year - wasn't said last year at test by same tester. Questions: a. Presumably the Suspension Arm is replaceable, but is the rear subframe? b. Presumably there's nothing much that can be done except for maybe cleaning it up and applying wayoyl or similar, but not sure how long that would last and sounds like an unpleasant job! c. Anyone ever actually had these parts fail due to corrosion, and if so at what age and mileage? (Mine has done about 90,000.
I've been looking at the undersides of Hondas for over 35 years, never seen serious corrosion on suspension components. I was a bit dismayed to see what was going on with our 2010 Prius suspension: lots of rust blooming. Weld zones in particular. And bolts, some pretty bad. I've heard here that the bolt coatings are not as good as in the past, due to tighter environmental/health regs?
Here is an example: Toyota Prius 04 09 Rear Suspension Axle Beam Sub Frame 42101 47040 | eBay Looks fairly replaceable.
check out the thread, 'any under-carriage rust from winter road salt?' by 'ski.dive'. there are probably some other threads as well.
