Introduction: How to Replace Trunk Lift Suppports

Looking to save money and gain great hands on experience fixing your car. Then you have come to the right spot! My trunk lift supports began to fail on my Lexus RX300. When I was searching for the cost to replace them I found it would be a few hundred dollars to take it to a shop and have someone else replace them. So, I decided to spend the $70 to buy the two lift supports and then swap them out myself. These instructions will be geared toward my Lexus, although everything should be similar for other vehicle models. The only thing, I foresee, that might be different are the bolt sizes. I have grown up fixing cars, thanks to my Dad and had success when I swapped out my own lift supports. I hope these instructions help you fix yours!

Step 1: Materials

To stay organized you should gather all of the materials listed below and bring them to your work site.
  • Long piece of wood or material to prop up the door (size varies)
  • 2 trunk lift supports
  • Ratchet
  • 10 mm wrench (I used an adjustable wrench)
  • 10 mm socket
  • Pan (to place bolts in)
  • Threadlocker blue

Step 2: It's Not Broken

When you are examining your new lift support you will not be able to make it go in and out yourself, this does NOT mean it is broken. If you can, move the support easily, then it is faulty and needs to be replaced. The lift support needs a lot of resistance because the door weighs a few hundred pounds. In the picture I am placing all my weight and the lift support still does not collapse.

Step 3: Prop Open the Rear

To begin, the rear door needs to remain open for the entire process. To do this, raise your trunk as high as possible and then place your piece of wood or other material in such a way that props the door open. It is important that the door is as open as possible. If your original piece of wood it to short find another or stack a few to make the height just right. I started my piece of wood from inside the trunk because I could not find anything longer. If you have a longer material the piece could start from the ground.

Step 4: Compare

Once the rear is open take your new support and roughly compare it to the old. Checking to see that the length looks about right and the design looks similar. Make sure you remove and replace one support before starting the next. This is a safety precaution as well as a way to potentially save time. If for some reason, when replacing a lift, you find it is not correct you only need to fix the one and not both.

Step 5: Note the Orientation

When swapping out the old lift support for the new, it is important to note the direction of the pieces. They need to be oriented exactly the same when replaced or the trunk will not shut properly.

Step 6: Closer Look at Orientation

The first picture is the top of the support. It is important to note the top has a ball shape and where the bolts are located it is shaped like a triangle. With the point of the triangle angled in, towards the inside of the car. The second picture depicts the bottom of the lift support. Notice that one side is flush with the car. When replacing the lift this should be fairly easy to remember because it will only fit a specific way.

Step 7: Using the Ratchet

Take the 10 mm socket and attach it to the ratchet. Make sure the ratchet is turned to the off position and loosen the top bolts followed by the bottom. Loosen all of the bolts before completely removing them. This will prevent any one bolt from holding all the weight.

Step 8: Wrench to the Rescue!!

When taking off some of the bolts the ratchet will not fit. This is when you will use the 10 mm wrench. I recommend using an adjustable wrench so, you do not have to keep picking it up and fitting it on.

Step 9: Don't Loose the Bolts

A total of 4 equally sized bolts should be removed. Place them in a pan to ensure you do not lose them. Also, compare the new support to the, now detached, old support. Again checking that there are no huge differences.

Step 10: Threadlocker Blue

Before the new support is bolted back into the car, place threadlocker blue on each bolt. This will become gooey, which will prevent the bolts from rattling out. Make sure you only place a small dab on each bolt and then work it into the groves by placing two of the bolts together and twisting one (see picture for help). To much of threadlocker blue and the bolts have the potential to not seat properly when being re-installed. The order the bolts go back in does not matter, however be careful not to tighten them to much. You want them to be snug and the threadlock should do the rest.

Step 11: One Down One to Go!

Once the first support is replaced follow the same instructions, return to step 4, for replacing the second. The only thing changing will be the direction of the metal pieces, where the bolts are located. For example the triangle shape, on one side the point will be to the right while on the other the point will be towards the left. It should be a mirror image.

Step 12: Checking Your Work

Once both supports have been replaced remove the material propping up your door, it should stay open by itself, and any tools that would prevent the door from closing. Slowly lower your rear door checking to see if there are any problem. DO NOT slam the door shut because if something was installed incorrectly you could damage your car and be in worse spot than when you started.

Step 13: Cleaning

Once you have finished installing the supports it important to wipe down your tools to remove any grease they may have picked up while being used.