Springs/Struts Install

The install of lowering springs in a 2G Prius isn't particularly difficult, it just takes some time due to the number of components that must be removed before you can even get to the point of removing the struts. The pictures below should be all that is required for installing most lowering springs in a 2G Prius, but if you need more, see the bottom of the VFAQ for links to the 04 Repair Manual docs used in this install. Note that the docs work well for an 06, there were no surprises.

The springs I used are Modellista springs for 15" wheels, an option available in Japan. See Priuschat.com or other Prius forums for info on companies that can get them, or there are several other companies with lowering springs available (finally!).

While I didn't replace the struts, this VFAQ covers everything you need to know on strut replacement, as the teardown is exactly the same for both, you have to remove the springs to swap the struts.

Click on the pics if you want to see the fullsize versions.

Front Struts

    Starting off, stock height.

    Here you can see on my 06 with about 500 miles on it, the front is at about 25 3/4" to the center top of the wheelwell.

    Start off by removing the cap on the driver's side wiper.

    Then remove the nuts (circled) on both wipers. Then drop the hood, flip the wipers up, and wiggle them off. Note: If your car isn't dirty like mine was, make sure to put some tape on the windshield under the tips of the wipers before removing them, and mark the tape where the tips of the wipers are, so you can make sure to get them back on correctly.

    Remove the rubber seal on the cowl. Just look under the front edge of the plastic cowl pieces for the white and blue tabs holding the seal in. Pinch them with your fingers, and lift up on the seal. Make either grip the tabs where they are inside the seal, or very near them, so that you pop the tabs out of the cowl, not out of the seal. Note that on my car, the far driver's tab was white, the rest were blue. If this is the case on your car, make note of it so you can put the seal back on correctly.

    Passenger side of the seal. The seal may have black, sticky butyl holding it to the cowl in various places, just lift up slowly until it tears loose (don't worry about tears, butyl is self-healing). Place the seal somewhere out of the way where the butyl won't stick to everything.

    The plastic cowl cover is in 2 pieces. Both pieces have pushpins on the outer corners. Just depress the center of the pushpin with something, then lift the pushpin out. The front of each cowl piece has tabs that snap into the metal cowl. Locate the tabs, push them back towards the back of the car while lifting the plastic cowl piece. Start with the driver's side, pop all the tabs, then lift the plastic cowl piece up a little, then pull towards the front of the car to unhook it from under the bottom of the windshield. Remove the passenger side piece in the same way.

    Next you need to remove the wiper motor. Unplug the power (circled), then remove the bolts shown (3 circled).

    Remove the rest of the bolts (2 circled), then lift the wiper motor assembly up and out.

    Unbolt this relay box from the metal cowl bracket.

    The relay harness is clipped to the metal cowl bracket in 3 places, seen here from the back side. Pinch the tabs in each clip (they're obvious on each one, but 2 have horizontal tabs, one has vertical) and pull the harness from the cowl bracket.

    Start removing the bolts holding the cowl bracket to the car (7 bolts total). Driver's side bolts shown.

    Center bolts.

    Passenger side bolts. Once all 7 are out, lift the cowl bracket out of the car.

    Jack up the front of the car and put it on jackstands. You can lift the entire front of the car, or do one side at a time as I did. Remove the wheel, then remove the stabilizer link from the strut. The ratchet has a 6mm Allen socket on it, it keeps the balljoint in the link from rotating. It's a Good Idea to have this, but in my case it wasn't necessary, as the link didn't rotate as I was removing the nut (nor when tightening it later).

    Remove the bolt holding the lines to the front of the strut. The one line just lifts out once the bolt is out, but the other is clipped to the strut - make note of how you had to rotate it around to get it off the strut, as you'll need to reverse this to put it back on later.

    Remove the nuts holding the strut to the spindle. Only remove the nuts, do not remove the bolts yet.

    Loosen the 3 top strut nuts until they are only on a few turns.

    Put a jack under the lower balljoint on the spindle (use a piece of wood to protect the balljoint), and lift the suspension until the bottom strut bolts can be pushed out. Then hold the strut, reach up and remove the top nuts, and pull the strut from the car.

    The front strut out of the car.

    Pry the dust seal off the top of the strut - just get a fingernail under the edge and pull.

    Crack the strut nut loose at this time - you'll probably have to use a pipe as a lever on your ratchet as I did - just crack it loose, do NOT try to remove it, or you're in for some serious pain!

    Place the strut compressors on opposite sides of the strut as shown. I bought some really cheap compressors from Harbor Freight, they were fine for the job. Note that on one side, you can get the ends of the compressor pretty far apart, but that is not possible on the other side. You want the ends as far apart as possible.

    Tighten the compressors. You don't have to crank them both down completely, just fully compress the "short" side, and compress the "long" side an equal amount.

    Once you start seeing/feeling the spring getting loose on the strut, you can stop cranking down on the compressors. Then remove the top nut - note the urethane washer between the strut top hat and spring top hat as shown - don't forget to put everything back in this order later.

    The circle denotes a cutout in the spring top hat and a tab in the rubber insulator. Make note of their orientation compared to the bottom of the strut to make sure you put them back on right later (better pics below).

    Remove the spring top hat.

    Remove the rubber isolator/shaft cover.

    Lift the spring off, then slowly back off the compressors, alternating back and forth between them every few turns, until they are loose enough to remove from the spring. DO NOT just loosen one all the way, then move to the other, as the spring will twist, and could pop out of the compressors.

    Place the new spring in place, drop the isolator into it. Make sure the end of the pigtail on the spring fits into the indent on the strut housing.

    Here's where the tab is important again. Orient the strut so that the tabs that held it to the spindle are pointing at you, as shown.

    With the bottom tabs pointed towards you, rotate the isolater until the rubber tab is pointing at you as shown. Place the spring top hat over the isolator, making sure the notch in the top hat is over the tab in the isolator.

    Not shown (as I don't have 6 hands): completing the strut assembly. Put the urethane washer over the strut shaft. At this point, you can complete the assembly several ways:

    • Use the compressors to compress the new spring, then drop the strut top hat over the strut shaft, and tighten the nut.
    • Place the strut top hat on the strut shaft, push down hard, and have a helper start the nut.
    • Place the strut top hat on the strut shaft, push down hard, and start the nut yourself. This can be tricky, but it is possible, as I did it. It's difficult to hold the spring compressed while getting the nut into place, but it is possible.
    I recommend using the compressors on the front struts if you are by yourself, it is the safest method. I only did it without as I have done many, many spring installs in the past, and know exactly how hard I can push and still keep a hand free for the nut.

    Now crank the nut tight. It's obvious when it is tight, you will feel the nut bottom out.

    Reinstall the strut in the car in reverse of the above, replace the wheel, and drop the car. Bounce that corner a few times, then measure the drop...and you might see what I did, virtually no drop.

    Don't worry about it, it will drop further as the suspension settles in.

    Modellista spring next to stock. You can clearly see the drop in height.

    After installing the rear springs, I measured again, and the front had already dropped 1/2" to 25 1/4". After a 30 mile trip the next day, the front was down to 25". I expect maybe a tiny bit more settling before getting it aligned.

Rear Shocks

    Stock height on the rear, 26 1/4". It might have been artificially high, though, as I jacked the rear up, forgot to measure, so dropped the rear, bounced it a couple times, then measured.

    Remove the cargo floor and lift out the cargo box.

    Pull the deck trim cover. Just grab the inside bottom edge and lift up.

    Remove the deck floor box. Just lift up the entire box, cover and all. Note the stud on the trunk floor, and the post on the bottom of the box - when replacing it later, make sure the post drops over that stud.

    Remove the 12V battery cover. The tabs holding it to the quarter panel are shown. You need to put a finger or 2 on that top edge of the large plastic tab, push the cover down, then pull the tab away from the quarter panel to pop those tabs loose. Once they are loose, lift on the back of the cover, then swing it towards the center of the car to get the front tabs loose.

    Remove the rear seat bottom, then the side trim panels (bolt circled). To remove the seat bottom, just wedge your hand under it about 10" in from the ends and lift straight up to pop the 2 clips holding it down, then lift up and forward while wiggling it out. With it out, you will see these bolts, one on each side. Remove them, then lift the side seat trim up and forward, wiggling it out.

    Remove the front spare tire D-rings from the front of the cargo area.

    Remove the rear spare tire D-rings from the front of the cargo area.

    Remove the front quarter panel bolt - this is in a very deep recess, you'll need a ratchet extension.

    Remove the rear quarter panel bolt.

    Remove the HV battery cover - peel the velcro from the seat backs as shown, then grab the back edge of the cover and lift straight up.

    There are 3 white pins holding the cover to the HV battery, as shown. They often stay in the battery, if they do, grab them with a needlenose pliers, pop them out of the battery, and put them back in the slots on the cover.

    Once you have the battery cover off, you will see a black pushpin on each side holding the quarter panels in. This is the passenger side, the pin goes into the battery cooling duct.

    This is the driver's side, it goes into a bracket you'll soon remove.

    Slip a needlenose pliers under the pin and the quarter panel, and wiggle it until the pushpin starts coming out, then move the pliers above the quarter panel and pull the pushpin out.

    These pushpins hold the battery cover and quarter panels to the car. Drop the rear seatbacks down to find them and pull them, then lift the battery cover out (you'll probably have to fight with the Velcro again). Remove the quarter panels - Start from the back hatch area, slip your fingers under the edge of the quarter panel, and lift away from the car a bit, you will see the white pushpins holding the edge down. Pop them all loose, then pull the quarter panels towards the center of the car to release all the top tabs. Don't pull the driver's side too far, you need to disconnect the cargo light before removing the panel.

    Once the quarter panels are out, you now have 2 very large brackets to remove to expose the shock. This is the driver's side shown, with the 4 top bolts circled. Remove all 4.

    There are 4 front bolts on this bracket. The Repair Manual has you remove the seat backs, but they're a pain to reinstall, and it isn't necessary. Shown is the top front bolt removed, and the lower front bolt. It's really buried down there, but if you have a 6" or longer ratchet extension, just lower the seat partway and work the socket to the bolt. Make sure you keep the socket on the bolt at all times, and once the bolt is almost out, reach down there from under the seat back and grab it to finish removing it, as if it falls out, there is a cover under the seat bottom it can roll under.

    The other 2 front bolts, top one removed. This bottom one is trickier, as you have to hold the seatback and rotate it through its' range until you find the right position to get the socket in there.

    Lift out the bracket, and you can finally see the top of the shock. It is held to the body with 2 nuts and a bolt from the underside. The lefthand circle is the bolt, the righthand is the nut.

    On the passenger side, you have to remove the HV battery cooling duct before you can remove the metal bracket. Use a pliers to release the tab holding the relay to the duct (top circle). Pull the pins holding the duct to the metal bracket (bottom 2 circles). Then push the duct towards the center of the car a little, lift the top of the duct off of the HV battery cooling fan, then pull the duct out of the HV battery and lift it out.

    The 4 top bolts for the bracket. Remove them.

    The 4 front bolts. Use the same technique to remove them as on the driver's side. Lift the bracket out.

    The passenger shock.

    Jack up the rear of the car and get it on jackstands. Then place a jack (with a block of wood) under the axle on the side you are working on. Raise the jack just enough to start moving the axle - you're not trying to support the weight of the car, you're just trying to support the axles a bit. Remove the wheel.

    The 2 nuts and bolt are circled. Remove the 2 nuts (left and top right circle).

    Remove the bolt from the wheelwell.

    Remove the lower shock nut and washer. Push the shock off of the shock stud, keeping a good grip on it. Lower the shock out of the car.

    The shock out of the car.

    If you have the 6mm Allen socket, use it to hold the shock shaft while you crack the nut loose. Just like the front, only crack it loose, do not remove it.

    Loosen the nut until it's even with the top of the shock shaft as shown.

    Place the compressors opposite each other and snug them on.

    Here you can see how I placed them so they wouldn't rub the shock top hat while tightening them.

    Once the spring feels a little loose, spin the nut off. Note the orientation of the top washer, put it back on with the cup up as shown. Remove the top hat with its' rubber isolator.

    Remove the shaft cover, lift the spring off, and decompress the spring as noted before.

    Not shown: completing the shock assembly. Put the new spring in place, replace the shaft cover. Replace the top hat and isolator. Stand the shock up, wrap one hand around the top hat, push down, and place the washer and nut on, and spin the nut on. Unlike the front struts, you should easily be able to do this without the compressors, as the top hat is easier to grip. Now crank the nut tight. It's obvious when it is tight, you will feel the nut bottom out.

    Reverse the removal procedure. For the "hidden" front bolts on the shock covers, it is easier to work your hand under the seat back and start the bolts, then fit the ratchet in there.

    Here you see the difference in height from Modellista to stock.

    Here you see the back dropped to 25 1/4". After that 30 mile trip, it is now at 24 7/8", and again, I expect a little more settling before I get it aligned.

    Get an alignment done within a few days of the install! I don't recommend getting one for a couple days to allow the suspension to settle - you don't want to have to take it back if you get it done right after installing the springs, and the suspension settles more. But definitely get one done a few days later.

    Once you have gotten an alignment, use the Headlamp Leveling procedure if you have HID headlights.

As noted, the various sections of the Repair Manual used are:

Please only download them if necessary, as some are very large.

Questions, suggestions, comments, constructive criticism and/or corrections? Fill out this form.

This document can be reprinted for personal use or reference for your mechanic(s) with no prior permission needed. It can be linked to directly, as long as you have a link to the main VFAQ page of http://www.vfaq.net/, though linking to the main page instead is preferred. This document can NOT be reprinted for profit/resale/redistribution of ANY type without expressed WRITTEN permission from me in advance. Bulk copying of this document onto your web site without prior permission will not be tolerated, link to it instead.
Last modified: July 26, 2007
Copyright 2006, Tom Stangl