Hello, can anyone tell me the name of this undercarriage part that goes in front of the tire?

It's all one part, the front horizontal piece, spat, and wheel well liner. There is a 3 bolt connection at the commencement of the wheel well liner, but those bolts are best consider rivets: at least in rainy climates they turn into rusty lumps.

It's item 9 here:

Fender & Components for 2014 Toyota Prius | McGeorge Toyota Parts

 

The front spat is part of one larger piece. Again, item 9 in the link.

Do a google image search to get better pictures, for:

53876-47070

The spat does bolt through two overlapped layers of liner, into a bar that runs along the inside, but they are low quality nuts, get hopelessly rusted up. So there's one part number, for the whole thing.

 

Yeah, good sleuthing.

There's the spat, then two overlapping layers (wheel well liner and horizontal cover from wheel well to front bumper), and then on the inside a steel flat bar, that acts like a big washer, with 3 weld-nuts. The bolts that pass through all the layers can get royally rusted up, in wet climates. I tried taking one off, and just snapped the head off. Not sure where you're at currently, but if you need to remove those bolts maybe start with some penetrant, and then use an electric impact, try to jar it loose.

 

Maybe substitute stainless steel pipe hanger and stainless steel nuts/bolts?

 

Did you miss applying boiled linseed oil there?

 

A good coating of Fluid Film will provide a lot of protection. Spray the entire bracket and all fittings and fasteners.

 

Yeah no kidding...

I just leave it be; it's one piece. Funny thing is, that's typically how toyota sells it, guess they expect it to turn to rusty doodoo.

Yeah if you catch it when it's new, good idea.

 

No, no, no... Mr. Mendel is boiled linseed oil guy. I haven't tried on mine yet. But the weather is better now, I am thinking of testing rust protection effectiveness, cost, ease of application, durability on boiled linseed oil vs fluid film vs RP-342.

 

Ahh, I see. Old school. Back when we walked to school both ways uphill in a snow storm...

I still use linseed oil on metal garden tools and wooden tool handles, but for the car, Fluid Film beats linseed oil hands down in my book.

 

I had two of my previous cars treated with Fluid Film. Unfortunately, I did not keep either of those two cars long enough to see the effectiveness. When I first got my PRIME before the first winter in NE, I took the car to the shop to have the Fluid Film applied as before. But the tech told me there is nothing he can apply the Fluid Film to without first removing all the plastic under covers. The cost of labor got too expensive, and I backed out. My car has not been treated so far, but I want to DIY to areas I can get to without too much trouble.

 

Part # 53852 - 47020 Left (driver) side
Part # 53851 - 47040 Right (passenger) side