DIY - Cutting Suspension Spring
As you know, their isn't much out there available for lowering your SN with coilover setups or better springs......except for one (King Springs Lowering Springs), but it's costly and not much of a huge drop that we all love. So here is a write up from a 5 hour workout on my friends '81 Prelude "Oliver".
I based this writeup off my current Prelude as it was lowered about a year prior to me owning it. This method is old and crewed from the glory days of doing it backyard style. Since no setup exists to buy straight off the market and installed right on your prelude (maybe in the future ), this method is as simple and easy to achieve with great results. As long as you cut once, measure twice on all fours....you'll be fine!
- I TAKE NO RESPONSIBILITY IN FUTURE OR PRESENT DAMAGES DONE BY THIS TUTORIAL TO YOUR PRELUDE OF ANY OTHER TYPE OF CAR YOU CHOOSE TO PERFORM THIS ON.*
Tools Needed: Safety Glasses Jackstand (low profile if you have one) Flat Head Screwdriver Rubber Mallet 10mm Open-end Brake Wrench Coil Spring Compressors (we used cheap advance auto part brand) Vise-Grips 6mm Allen Key 1/4" Ratchet Ratchet Extension 10mm Socket 17mm Socket 19mm Socket 4-1/2" Grinder (Any brand will work) w/ a 1/8" Grinding Disc Marker PB Blaster (MUST BUY THIS STUFF NOW) Your Right Foot (Yep not joking...just don't remove it) Good Music Playing 4 hours of your time!
1. First things first, make sure you have all the tools listed above (more doesn't hurt) and find a good place to park your SN. We chose outside my friends garage with the beautiful weather.
2. Pull the E-brake, stick the car in gear, grab you jackstand and start on the front. Either side, whichever you prefer first. This is also a good time to loosen the lug bolts before you raise the car as the old brakes will sometimes not hold the wheel as the picture shows below.
LOWERING THE FRONT OF THE CAR - 2.75" Drop
3. Pop off the top hats on the strut housings and hopefully your upper strut bolt won't be too badly rusted. If so, grab a good bolt lube (we used the almighty PB BLASTER) and spray around it, wait about 5 minutes for it to seep in.
4. Next take off your wheel and admire your brakes. Here you can see our '85 Accord Brake swap looking good with some EBC Green Stuff.
5. Now look at your Strut and your Knuckle housing to see how their attached. Unbolt the two bolts circled.
6. Grab yoru can of bolt lube and spray around the strut where it attaches to the knuckle. This will help loosen it.
7. *Important* Keep the upper part of the strut still bolted down. This will help aid in pulling the strut out of the knuckle.
8. Here's a picture to show what direction the knuckle and strut need to go.
9. Now making sure the car is securely on jackstands and the ebrake is on. Take your right foot and place it on top of the rotor.
10. Slowly start to put pressure on the rotor. We had to jump up and down for it to slide out. This will not hurt your rotor or hub, as long as you are Goliath and weight over 400 pounds. Just slowly apply pressure and watch your axle as well. If you pop the strut out and keep pushing down on the knuckle, your axle will pop out from the transmission leading to fluid going everywhere. Might be a good idea to place a pan under the car for safe measure! For us we pushed too hard and it popped out. It easily popped back in place though.
11. Once the strut is out of the knuckle. Support the knuckle with something underneath, a coffee can works great. Then go to the top of your strut top and start to loosen the bolts. Place the 6mm allen key in the strut while taking a 17mm wrench and turning it against each other. Don't worry about the spring popping out at you. Our front struts are a combination of two top hats (similar to a Volkswagen design), so you really just taking off the top portion of the strut which isn't compressed by the spring. DON'T loose the rubber bump stopper that is under the top hat. It's shown in the third picture.
12. Now it's free!
13. Next, take your strut somewhere open, we used the garage for the first time *GASP* :lol: You can also take them to a shop to have the springs removed if you fancy. if not, take your spring compressors and follow their instructions on how to use. We simply made sure all four arms were attached to the coil when we started to tighten them.
- I TAKE NO RESPONSIBILITY IN ANY ACCIDENTS WITH THE SPRING COMPRESSORS. USE AT YOUR OWN RISK*
14. With a friend (highly recommended), slowly working in rhythm at the same pace while tightening the coil. MAKE SURE you tighten in the same speed as the coil needs to be evenly tightened or else it could potentially pop out at you resulting in massive injury or death. I'm not joking. Observation is key here!
15. Once the coil is compressed (you'll be able to move and rotate the strut perch and top hat easily, Take you 6mm allen key and adjustable wrench. Undo the bolt and remove it as so. If the bolt is loosened and the top hat is moving with it, go back to tightening the coil more as it's not tight enough. You don't have to compress it all the way, just enough to where there's no pressure on the top hat and strut perch.
16. remove the strut from the coil and take a flat head screwdriver to remove the top hat from the coil. Ours was stuck on there from 30 years of use!
17. Now slowly undue the spring with an even pace and speed. Again, if you do not keep the spring even on both sides while undoing the spring compressors, the spring will pop out and can lead to massive injury or death. Caution is advised.
18. Once the spring is undone, make note of the coils and our counting system we used. We count each 360 degree on the coil as 1 from the bottom. We want to cut the coil spring at the 4-1/2 mark. Observe the picture and mark your coil to where you'll cut it at. If you want to make it less or more, we figured the math to be roughly 11/16"-3/4" drop per coil cut!
19. Lay the spring between your legs, grab you safety glass and your grinder. Start grinding away!
20. Mind the coil from being HOT, put everything back together in the same order you took it apart. Revisit the picture above if you forgot what order the bearings & seals go back on. No need to tighten the coil as it's shorter and will not need compression.
21. Easiest solution we found to put the strut back in was to slide it back in the knuckle first and than bolt it down on the top.
22. Make sure everything is torqued to spec and tight. Repeat steps 3-21 on the opposite side. Once done, pull out the jackstands and lower the jack. Might be wise to check spring placement as you slowly lower the car back down so the coils seat properly. They won't be absolutely perfect but they'll be fine. Now admire your half way done job!
Now for a little RnR with a friends Jeep!
LOWERING THE REAR OF THE CAR - 1.75" DROP
Lowering the back is almost identical to the front minus a few small things. The differences being the strut tower has two bolts that need to be loosened, you'll have to disconnect the brake line & the rear coils are tampered unlike the front which are straight.
1. Grab the jackstands and migrate to the back of the SN. Use the tow hook in the center of the rear as a jackpoint and raise it up (Make sure the car is in gear). Place jackstands underneath and lets begin!
2. You'll first want to keep the top portion of the strut bolted down (same as we did for the front) so when you put down on the rear trailing arm, the strut housing will pop out of the knuckle. Take a look at what you'll be dealing with. You'll have to disconnect the brake line as it won't slide off and undo the bolt on the knuckle.
3. Using a 10mm open-end wrench, slowly undo the brake line, making sure not round the nut or else you'll be looking for a replacement. Lay it off to the side with a pan underneath to collect the brake fluid.
4. Now undo the knuckle bolt.
5. Next spray some bolt lube around the strut housing to help ease it out. Take your foot and start to push down on the knuckle (be sure the car is secure at this point).
6. Once free, unbolt the two 10mm bolts holding the strut to the strut tower.
7. Take your strut assembly to an open area (we used the garage again) and get the coil compressor on it. Please refer to the beginning of the thread for safety on using the spring compressors and the danger behind them. In an even rhythm, compress the spring just enough to where both ends of the assembly are loose.
8. You'll notice that there are two 19mm nuts holding the strut down. Since there is no allen key hole on the strut, there are two methods that can be used here to undo the nuts. One is to get a vise grip on the end of the strut, you'll notice it's squared off slightly, and clamp it down. With the strut on it's side, use the vise grips as a means to block the strut from rotating and undo the nuts with your wrench. We found this didn't work too well so we resorted to plan B.
9. Clamp the vise grips down on the furthest part of the strut to keep it from moving. We realize that this isn't the best solution in the world but it worked well and we haven't had any problems with leakage or damage. The idea is the vise grips will leave small marks on the lower part of the strut which rarely will be raised above the opening seal to cause leaking.
10. Grab your 19mm socket and with the vise grips, undo the 2 bolts. They both came off at the same time with us.
11. Next undo the compressors in an even rhythm, allowing the spring to be undone with out any problems. Refer to the beginning of the the DIY for more information.
12. Now one thing to keep in mind with the rear springs is that their tapered inward at the top, making them a little more custom fit in the spring perches than the front coils. You'll notice they taper inward from the bottom to the top. The best place to cut the springs is the bottom since the top is smaller in diameter and cutting off more will increase it. Better to have a smaller diameter in a bigger perch than the opposite.
13. For the rear, we only took off about 1-1/2 Coils on the bottom.
14. Once marked, lay the spring between your knees and grind away!
15. Grind off the bottom so it seats better in the perch and re-assemble the strut assembly in reverse order!
16. Slide the strut back in the knuckle, use more bolt lube if you have too.
17. Re-bolt the top of the strut to the strut tower. Can be tricky since the spring is cut.
18. Bolt the knuckle together and connect the brake line.
19. Once everything has been torqued and bolted back, take out the jack stands and slowly lower the car.
- Critical Point to be made! Since the springs are tapered and now cut in the back, grab a friend and watch the springs seat properly when lowering the car. Once the springs grab onto their perches, you can be assured their ok. YOU MUST do this every time you jack up the car and lower it. If not done properly, the spring will not seat in the perch properly and will do strange things, the worst being it could start to coil itself and stretch. *
20. Once done, let off the ebrake and admire your new lowered SN! Good Job sir, you've just made it look 10x better!