Can anyone tell me the function of this part?

That is your central jack point for the rear.

@SFO can tell you all about it.

Doesn’t look like much, but it does the job.

 

You can also use it to increase tongue weight / overall strength when installing a trailer hitch...

 

I heard that was possible. Any details? I am interested in this.

 

I suspect some trailer hitch makers would offer that strengthening extension, but not the most popular hitch makers. The basic concept is welding one or two pieces of steel to the tow hitch surface and extending that long lever(s) to bolt to that mounting bracket.

Currently my Curt hitch is slightly bent from too much tongue weight and I hope to repair the damage or modify with this system, but I'd have to buy a welder and get good at welding first. If we lived near each other we could work on it together, but there's too much distance for a collaboration. But who knows? Maybe you have a scheme I've yet to consider?

 

...or find a welder to do it for you.

Also, I expect you would have to use angle stock if the lever arm is long - I'm guessing 1/4 inch steel angle would be required to add significant load bearing - and there you have a strength-weight trade-off. Titanium angle would be even better, but it would be expensive and would have to be bolted, not welded. Also, either configuration would have to be pre-tensioned which would make installation difficult.

I too have a Curt hitch (U-haul installed) which is limited to 200 lbs loads and requires the use of a support strap. I am hoping to find a way to increase load capacity.

 

Do a product search on 2" inch receiver for Prius... There's a company that makes a monster heavy duty one for gen3, not sure about Gen2

 

I couldn't find it. There's one comment in a thread regarding a 2" hitch mod, but the comment provides a post that now links only to the top PC forum menu with no further guidance. That suggests to me that whatever details were provided are probably no longer available. After thinking about it, I am more inclined to try to ruggedize my 1 1/4" Curt with a removable torsion lever. You would have to loosen the hitch to install the lever, and then tighten the hardware to apply torque.

 

Well... Yet again a long conversation about the strongest hitch for Prius that we had last Summer, which had the link to the most heavy duty hitch is impossible to find using all the search engine tricks I know... The SEO on PriusChat is a such an epic fail. It's so hard to find vital information. I used to be a web tech journalist and I have tons of ways to dig up information, but quickly realizing that this forum is so screwed up, most of the discussion we have on it are impossible to find later on. I'll keep looking, I'm sure you will too.

 

Ok, finally found it... Had to go into incognito mode because my current settings google search account are totally screwed up... Here it is: Torklift Central | Torklift Central | 2010-2015 Toyota Prius and Prius Plugin EcoHitch

 

The jack location.

Posted via the PriusChat mobile app.

 

OK. Thanx. The Curt hitch mounts to the six bumper mount bolt positions. These look completely different. I'm going to have to dig into this further.

 

I love the rear jacking point, so easy to find and use. Is there a specified front jacking point that is recommended to lift the car by? And then after doing so, what are the recommended places to put 4 jack stands?

 

According to the owner's manual ...

 

Toyota recommends the scissor jack locations. On our 3rd gen I did that once, and wasn't much impressed, settled on the marked points. I believe second gen is similar enough:



Some pics of the front locations:

Prius Jackstand position | PriusChat

The rear locations, I turn the jack stands 90 degrees, basically the cradle is at the "hump", directly adjacent to the distinctive oval plugs (on holes employed for locator pins during shipping?).

Both the front and rear locations are heavy, reinforced plate. No problems using these points for over 9 years now. I have the whole car on jack stands at least twice yearly for tire swaps, and more times, front or rear, for oil changes, brake work and so on.

 

My 1 1/4 curt does not look anything like that. It has one big rail on each side that 2 very big bolts that bolt each side rail to the chassis. I can’t see how welding anything to the body not the frame is going to make that stronger. It looks like any other hitch. Very strong. If your bending up the hitch your load must be super tongue heavy.

 

If there are just two bolts on each side, it's just a matter of measuring the distance between the two, compared to the horizontal distance out to where the gravity load is being applied to the hitch.

If you're towing a trailer, you're in luck, because the trailer typically has a lowish tongue weight, and that's just applied straight down on the hitch ball, which is not very far out from the car, horizontally. A foot, maybe? So if there's a 100 lb tongue weight coming down on the hitch ball, that's 100 ft lbs of torque on the hitch. Figure the two side mounting positions are identical, each resisting 50 ft lbs of torque, with the contact points being two bolts 3 inches apart, a quarter of a foot. The lower bolt is being pushed toward the car, the top bolt pulled away, by about 200 lbs on each side.

It gets more interesting if you have, not a trailer, but some kind of rear bike rack or cargo rack. The center of gravity of that thing might be two or three feet horizontally back from where the hitch mounts to the car, so 100 lbs sitting out there could be 300 ft lbs on the hitch, applying 600 lbs of force between the bolts. That's just the static picture, not accounting for the forces when you drive over bumps and stuff bounces.

That's why the picture can be improved a lot just by adding more mount points a larger distance apart. They don't even have to be especially sturdy mount points, if they're far enough apart.

That's back-of-the-envelope math up there; exact calculations for a particular hitch would start with a drawing of its shape.

 

yea... If you use a hitch-haul or bike carrier on a Prius you'd be wise to shorten the length of that lever to reduce force. The people who make that gear leave lots of length, which makes it easier to use, but way more force on your hitch, which typically has a tongue weight in the 200 pound range.