An ultra safe rear jacking adapter plate for tire changing and work in brakes

Since I first got my Prius, I explored the safest way to jack up the rear corner of your Gen 3 Prius to change a tire or to do brake work.


The problem was how to raise one rear corner of my Prius just enough to get the tire off the ground to remove the tire without a high lift extending both the shock absorber and spring to maximum length making it less safe.


We machined of the peek (polyetheretherketone), one of the most durable but expensive commercially available plastics invented in the 1970’s for the space program.


Placing the floor jack under the spring mount means that the jack needs to lift the rear corner of the car only an inch above the pavement with one third of the needed pumps of the handle. Oftentimes any movement of the car like jacking up the front with another jack would cause the bottom of the spring mount to slip off of the top of the rear jack, Locking the top to the spring mount means that any movement would be done by the jack’s wheels, not sliding off of its top.


The top is made to fit into the center hole of the spring mount and the bottom is recessed to fit the head of any inexpensive two ton trolley like the $33 Walmart Hyper Tough model shown, with the swiveling cup removed. (easily done by pulling the retaining pin holding the center retaining rivet.) The adapter plate will also fit any flat top racing floor jack.

 

The key to the design is to make changing the rear tire, working on the rear brakes or replacing the rear wheel bearing as safe as possible.

Jacking up using the rear jacking point means raising both rear wheels off the ground by 10-12 inches. That's a long distance to fall off the jack.

Using our tool means that three of the four wheels are still sitting on the ground. One wheel is raise about an inch off the ground. Basically, the car is sitting at ground level.

Even if the jack fails and collapses with the wheel off, the jack, locked onto the spring mount will still keep the brak disk from hitting the ground.

 

Today, I went out to my local Toyota dealer and measured the center hole on the rear lower coil spring mount on the 2023 Rav4, the Corolla, the Camry and especially the 2023 Prius.

They were all within 0.15 inch or each other, The 2.018 or 55mm center post on my adapter plate will work perfectly on all.

I've uploaded a photo of the left rear spring of the 2023 Prius.

 

Update:

The jacking plate has been further machined to fit the top pf any OEM supplied scissors jack, so it will allow changing a tire with minimal lift for extra stability.