• How I lifted my Previa

    I did some searching for a pre-fabbed lift kit, but could find nothing for the Previa. Since I have some experience as a tool maker and fabricator, I decided to build my own. Since the tire size is limited by the front struts, I decided that 2" would be about right for this project. Here are some pictures and details:

    I decided it would be easier to modify existing strut mounts than to build something from scratch, so I went to http://www.rockauto.com and found one their famous "close-out" sales on Previa strut mounts. I ordered 4 of these for only about $20 each. Here's what I got.




    The idea is to stack the strut mounts and weld them together. If this is going to work, then this bearing must be removed from the top mount (I'll need enough room to get a socket and extension down in there to install the strut mounting nut). This bearing is pressed in and also has a metal lip crimped in over the edge of it.


    Here is my answer to getting rid of that crimped metal that's holding the bearing in place.


    Here's what's left after 5 minutes with a die grinder.


    Now bearing can be driven out of mount.


    Okay, bearing's gone. That's it for the top mount.


    Lower mount doesn't need these 3 studs, so using a socket and a vise I press them out.




    Okay, that's it for the lower mount.


    Now it's time to do some shopping at the steel yard. I take the mounts with me and snoop around in the scrap pile. I find the perfect diameter and wall thickness, and have the metal guy cut me 2 pieces, each one 1 7/8" long.


    Burs are removed from the tubing and I use a wire wheel to remove paint from the places I want to weld on the strut mounts. Mounts are stacked together with metal tubing then clamped for welding. I use a hammer to gently tap parts into perfect alignment. Here we are ready to weld.




    Here's where the Tim's RV welding van comes in handy!


    To avoid overheating and damaging bearing, I decided to stitch weld and to cool after every 2 or 3 segments. This should be plenty strong.


    And here's the finished strut mounts after painting. These will lift the front exactly 2" higher than stock.






    Next I put the Previa on jack stands and remove the struts. Here is one ready to have the new mount installed.


    Spring compressor tools are a MUST. People have been seriously injured by removing mount nuts without 1st compressing and securing the spring.


    Once spring tension has been removed from the mount, the nut can be removed. Note: Strut should be laying on the ground aiming away from you and others (just in case the spring compressors slip). It's better to have parts flying sideways at ground level then to have things flying up toward your face .


    Here's the strut sporting it's new extended mount.


    Here's the top of the strut with the nut securing it to the new mount. That old bearing hole gave plenty of access for a socket and extension!


    Putting the extended strut and mount back on was a little more difficult. Things didn't want to line up due to the increased articulation of the A-arm. I was able to get the bottom bolt in by hand, then using a big C-clamp I forced things into position and installed the top bolt. Due to my concern of adversely affecting camber, after top bolt is pushed through, I tightened clamp more until bolts are pinched, then tightened nuts. This is not enough to compensate, but I'll take what I can get.


    Here's what you can see of my mounts after installed.




    Look at this unloaded lift!!!!




    Okay, so there's a problem. This extra lift has made my inner flexible brake lines too short. I have my buddy at Napa look these up, take note of the specs, then find a new line that's 2" longer. No dice on the 2" longer, but he finds ones that are 1 3/4" longer!!! This is so cool! I'll take 2 please!





    Note the wire tie holding my ABS sensor wire to the old screw mount. The nut plate and the screw part of the clamp are still attached to the wire harness, but I am not using these now. Length is okay with wire like this. Wheels can now be turned from stop to stop without interference on brake lines or ABS sensor wires.


    Okay, brakes are bled, front tires put back on, front is done!


    Time to do the back. I figured the best way to raise the back is to find longer springs, so I ordered a Moog catalog and started searching based on inside diameter, length, and gauge of spring. There is some guess work involved, and of course, a perfect match is illusive. A couple of springs come close to what I want. One is 3/4" shorter than what I want, but the gauge of the spring is about 10% bigger. The other is about 2" too long and also about 10% bigger gauge. I could get the longer ones and cut them down, or get the shorter ones and hope for the best. Well, I opt for the shorter ones and cross my fingers. The shorter ones are stock replacement coil springs for the front of a 65 Ford Mustang with a 6 cylinder engine. This is good news because this is a popular classic car and springs should be readily available. I go to http://www.rockauto.com and sure enough, I find my springs. I go with the Husky brand part # RC8088. These only cost $56 for the pair.

    So, with the Previa on jack stands (weight supported by rear axle) I remove the wheels and shocks and take a measurement.




    Next I disconnected the LSP & BV (Load Sensing Proportioning & By-pass Valve) linkage, support the rear of the van using the jack points and drop the rear end. There is enough articulation for me to remove the old springs by hand (no spring compressor needed). Here is an old spring next to a new one.




    Spring compressor is needed to install new springs.


    Springs are installed and jack is put back under the rear differential. I jack van up until weight is again supported by differential. Measurements are taken again. YES! the gamble paid off. New height is exactly 2" higher than before!!!




    Okay, so I go shopping for longer shocks. Bad news, nobody makes this type of shock that's 2" longer. Well fine, I'll modify some Monroe Gas Matics.

    Shock extenders would make the shocks too long, so I made my own extenders. The threads don't go far enough to do what I want, so I use a 3/8-16 die to cut some more threads. I purchased some 3/8-16 coupling nuts from the hardware store. I measured the nuts, then cut threads deep enough to position the bottom of the nut exactly 2" down from the shoulder on the shock.










    Now that the threads are cut, I measure and cut off the excess shock bolt. The objective is to have the threaded portion of the shock fill 1/2 of the coupling nut.






    Here is some 3/8-16 threaded rod I picked up from the hardware store. I cut off a piece and thread it into the other end of the coupling nut.


    I use double nuts to get a firm grip for tightening. This is nice because it won't damage the threads like a vice or vice grip would.


    I measure and cut to the same length of the old threaded area.




    Here's the extended shock next to the stock shock.




    And here's my new extended pair of Previa shocks.


    Okay, so the Previa has a LSP & BV (Load Sensing Proportioning & By-pass Valve). The LSP & BV's job is to increase braking power to the rear wheels when there are heavy loads in the van. As the weight increases, the suspension becomes more loaded and the rear end moves closer to the body. As this happens, the LSP & BV linkage pushes the arm of the valve up, and the LSP & BV allows more brake fluid to flow to the rear brakes. Due to the position of the valve linkage on the suspension arm, using math (and a little guess work), I determined that a 2" lift requires the LSP & BV linkage to be adjusted .78" higher to compensate.

    1st thing is to unclip the top of the spring retainer.


    Next thing is to loosen the jam nut at the bottom of the lower spring retainer. I was careful not to move the lower nut so I have a point of reference.


    After adjusting (extending) the linkage .78", top spring retainer is reclipped, and jam nut is threaded back up the rod and tightened against the adjustment nut.




    Okay, so there's one last thing. I was going to ignore this, but the thought of bottoming out and shoving a shock through the floor made me reconsider. Considering the increased stiffness of the rear springs, I doubt this would happen, but decided to drop the rubber snubbers just in case. This is a simple task, and all I did was cut some pieces of 2" steel tubing and drill some holes in it. I used these pieces as spacers for the snubbers. The hardware store had some metric bolts the right length, so installation was easy. Here's some pictures of this mod.











    So I finished it all and took it off of jack stands tonight. Here is the height from the concrete to the bottom of the passenger door area.



    Here is the height of the front bumper.


    New clearance of left front tire.


    New clearance of left rear tire.


    I drove it around the yard and it rides nice. 2" isn't very much, but it's very noticeable. I am still a little concerned about the camber issue as I don't see an adjustment for that on the van. I'll be taking it in for an alignment next, and I'll consult with the alignment guy. I may end up doing a few more mods to get that within specs and I will post this information here as it becomes available. Tim
    This article was originally published in forum thread: How I lifted my Previa started by timsrv View original post
    Comments 2 Comments
    1. kurtdaniel's Avatar
      kurtdaniel -
      cool writeup.. tnx for sharing this.. I also want to change my previa shocks into a longer one.. I will try Bilstein B8 from carparts.com.. i heard a lot of good thing from it..
    1. wharangi33's Avatar
      wharangi33 -
      thanks for the information, luv the fotoz. Clear az