Knowledge Base - How To:- Swap Your Suspension Struts & Springs
How To:- Swap Your Suspension Struts & Springs
You will have to excuse me if this seems a little narrative it's just the way I wrote it.
Hmmmm where to start? at the beginning I suppose, I have been getting the dreaded knocking noises for some time, from the rear of the car mostly but occasionally from the front too. On top of that, just lately whilst driving on motorways and smooth roads the car has been "shimmying" which is the best way I can describe it. It has a sort of cyclic side-to-side motion, snaking I suppose, which is not how it used to be.
To begin with I thought it was my 17" wheels causing it, but I have now changed back to my Rev2 standard 15" wheels for winter and it's still the same. I'm now convinced it is a combination of tired old shocks & springs along with drop links, ball joints and generally bushes throughout the car. Hence my mission to replace everything with new or improved components, after much searching on this forum and others, the shopping list I came up with (see below) will give me the combination of ride comfort and handling that I am looking for whilst lowering the car enough to improve it's aesthetics.
Bilstein Yellow B6 Struts
Tein S-Tech Lowering Springs 35mm drop approx
Front & Rear Ball Joints
Front & Rear Drop Links
Full Set Of High & Tight Polyurethane Bushes Front & Rear
Powerflex Shock Absorber Bumpstops & Gaiters
Goodrich Stainless Steel Braided Brake Hoses.
When I first set out to replace my suspension I had intended to use Koni SSK inserts and springs. I could see that doing the shock and spring replacement utilising my existing re-build able struts was going to take lots of time and would mean my car being off the road for a long time. So I started my search for a set of spare struts that I could strip down at my leisure, clean up and fit the Koni SSK kit, which would then save me time later on. I was lucky enough to be offered a set for the princely sum of £40.
Ultimately I decided not to go the Koni route, but what this did is provide me with a set of front & rear topmounts in very good condition, the front mount bearings were very smooth and had no play in them and the rubbers of both front and rear mounts were not perished and were solid. They basically needed to be de-rusted as well as possible, which I did using a bench grinder with a wire wheel mounted. Then using some machinery enamel I gave them a couple of coats of paint.
I've decided to do this in two distinct separate stages, first I'm going to concentrate on theshocks and springs and change them first with the new drop links. Then after a test drive to gauge any improvement I will then do the polyurethane bushes and ball joints and then another test drive to see if there is further improvement. I don't have the luxury of being able have the car off the road for extended periods of time. I'm still looking for a place local to Norfolk that can do 4 wheel Laser alignment, so if anyone can recommend somewhere I will be suitably grateful.
Today I assembled the new struts, I started with a front strut for no particular reason, it's just the first box I opened. The first job was to fit the Powerflex combined bumpstop and gaiter.
At this point it is worth noting that the very top of the piston rod there are two flats which when everything is assembled need to fit in the corresponding location in the top cup. I worked out that these flats needed to be lined up so that they faced the outside/inside of the strut rather than across. Anyway I found it was a good idea to orientate these flats now to prevent twisting the secured gaiter later on.
Fitting the gaiters entailed trimming the bottom to fit the top of the strut leg (there are two stepped collars). Cutting the smaller of the two off made it a perfect fit, and then all that was needed was to slide the gaiter and bumpstop over the top of the piston rod and secure the gaiter to the strut and to the bumpstop with cable ties. See pic below:
Next step is to fit the front coil spring, this has a flat wound coil at one end which needs to be facing up, the end of the coil at the bottom needs to fit in the location on the strut cup. See pic:
Next piece to fit on the front strut is the top cup; this has a rubber insulator or cushion if you like fitted to the underside. See pic:
This cup is then inverted and fitted cushion down on top of the spring. If you look at the top surface of the cup you will see the word OUT and an arrow, this needs to face outwards, you can just make this out in the picture below. The way to judge this is to line the word OUT & arrow up with the hub mounting lug at the bottom of the strut since this faces the outside of the car when installed. Having done this the pink coloured dust seal then needs to be fitted, see pic below.
Next step is to place the topmount itself in place see pic below.
I then enlisted the help of my trusty assistant Maggie, while I pressed down on the cup with two hands, she spun the top nut on as far as possible. This was surprisingly easy to do since there only needed to be about 30mm compression to get the nut on. If you are doing this on your own then it would be relatively easy to compress the spring using proprietary spring compressors which I had to hand just in case. A word of caution here though, I would not recommend trying to remove any car coil spring without the aid of compressors since it is impossible to know the level of compression an existing spring is under. Once the nut was in place I then used a ratchet & 19mm socket to wind the nut on as far as possible, making sure that the flats on the piston rod were located properly in the top cup. I will torque them up finally when installed in the car. Below is a picture of the front strut fully assembled.
Next I attacked the rear struts, same procedure as before required to attach the bumpstops and gaiters in place, once again remembering to align the two flats at the top of the piston rod inside outside before tightening the last cable tie. Again to prevent the gaiter getting twisted when lining up the top mount later. The rear coil springs also have one end flat ground, which needs to be facing upwards, whilst the other unground end needs to locate in the strut bottom cup as shown in the picture below.
The top mount and top cup of the rear shock is a one-piece item unlike the two-piece item at the front. This needs to be fitted on top of the ground end of the spring, it again needs to be lined up with the mounting stud which is the odd one out (tip of an isosceles triangle) facing the outside of the car (hub mounting lug side). There is then a spacer, which goes on before the top nut.
Again my trusty helper Maggie spun the top nut on while I compressed the spring about 30mm but as I said before you can use a set of spring compressors instead..it just takes longer. A word of caution here though, I would not recommend trying to remove any car coil spring without the aid of compressors since it is impossible to know the level of compression an existing spring is under. I then tightened the top nut up fully, making sure the flats on the piston rod located properly in the top mount. I will again torque them up fully when installed in the car. See picture below of the fully assembled strut.
Had some time this morning before going to work so decided to make a start on swapping the old shocks out for the new ones. I used a trolley jack in the center of the rear cross member and got the car high enough to install axle stands at each end of the same cross member.
I then removed both rear wheels, after this, the first job was to spray all the nuts and bolts with WD40 hopefully make them easier to remove. I decided to start with the drivers side shock first.
As I am replacing the rubber brake hoses with Goodrich SS braided lines I decided to swap this over first. I applied the brake hose clamp to minimise fluid loss then undid the banjo bolt at the caliper end, next the bottom clip where the hose is secured to the strut needs to be removed which then allows the hose to thread up through the strut bracket. Now it was just a case of undoing the two bolts that secure the other end of the hose to the inner wheel arch. I then bolted the new hose top bracket to the arch, then swapped the hard brake line connection over and applied the hose clamp to the top of the new hose, again to minimise fluid loss, I left this hanging ready for when the new strut was installed.
Next up was the removal of the drop link, since I am replacing my drop links I only needed to undo the ARB end of the link. This is accomplished by using a hexagon 5mm allen key to prevent the ball joint of the link from turning while the nut is undone with a 14mm Metric spanner. I was lucky and managed to get the nut off but just in case I had my trusty angle grinder nearby, which I suspect I will have to use at some point.
Having done that I then loosened and removed the hub to strut mounting bolt nuts using a breaker bar and 19mm socket. I removed the lower bolt totally but left the upper one half in to stop the strut dropping and potentially damaging the CV boot.
Time to look at the top end of the strut now, first I needed to remove the engine side panel and the top mount dust cap to gain access to all the strut mounting bolts.
I didn't need to do this, but here is a handy tip if you are removing your struts to replace the springs or inserts: Loosen the top piston rod nut(19mm) ¼ of a turn before taking it out of the car, it's much easier to do this now than when the shock is off the car.
Next I undid and removed two of the three (13mm) top mount securing nuts, the third one I undid and left screwed on a couple of turns. This was so that when I removed the final bolt at the hub end of the shock, it wouldnâ€™t drop down unsupported.
I then removed the second hub mounting bolt and eased the hub assembly out of the bracket at the bottom of the strut with the aid of a large flat bladed screwdriver. Then while supporting the weight of the strut I was able to reach up and remove the final top mount nut. It was then just a case of gently threading the strut down and out of the wheel arch.
Now it was time to install the new strut that I described building up earlier. This needs to be threaded up past the disc and hub so that the three top mount studs locate in the holes in the strut tower. Once these are located I span the three nuts on loosely for the time being. Being careful not to damage the CV boot I then fitted the hub-mounting lug into the bracket on the bottom of the strut, this just needed me to press down with a little weight until it slid in, and the mounting bolts were then re-instated.
I then tightened these up to the recommended torque of 188 ft-lb
Next step was to install the new drop link, which was straightforward, and then these were tightened to the recommended torque of 36 ft-lb. At this point I threaded the brake hose through the strut bracket and secured it with the spring clips. After reconnecting the hose to the caliper, using 2 new copper crush washers for the banjo bolt, I then used an easy bleeder to get air out of the system.
Next step was to tighten the three top mount bolts to the recommended torque of 59 ft-lb and the shock absorber piston rod top nut to 54 ft-lb. The top mount dust cover and engine side cover were then re-installed.
Repeat the above procedure to do the passenger side strut.
Time to start on the front struts now, at this point my camera was in use elsewhere so I wasn't able to take any pictures. Fortunately I have found someone elses pictures that I'm going to use instead (Many thanks go to Randall Aiken).
As with the back struts, I jacked the car up using a trolley jack in the middle of the wheel well, then placed axle stands under the sill jacking points and lowered the car onto them. First job to do for someone changing their struts and re-using their springs etc is to loosen the center nut ¼ of a turn whilst still on the car, this will make it easier for you to dismantle them once off the car.
I then slackened all 4 of the top mount nuts just a few turns for now so that the strut couldn't fall through when the bottom was released.
The next step was to release the bottom banjo bolt from the brake line where it connects to the caliper, then after removing the bottom clip from where the line is secured to the strut I then threaded the hose up through the bracket.
Next came the removal of the droplink from the Anti roll bar, this should have been accomplished in the same manner as the rears but unfortunately this one needed cutting off with an angle grinder. However this picture is of one successfully removed using the 5mm allen key to stop the ball joint turning and a 14mm spanner to undo the nut.
The two bottom strut to hub mounting bolts were removed next using a breaker bar and 19mm socket, then using a large flat bladed screwdriver inserted between the hub lug and strut I eased the two apart whilst pressing down on the hub itself.
Then with the bottom of the strut separated it was just a matter of removing the 4 previously loosened top mount bolts while supporting the weight of the strut and then threading the whole strut out through the wheel arch. Although the following picture is not my front strut, mine looked identical, right down to the rusty strut body and the destroyed rubber boot.
Now I was ready to install my pre-built struts (see the beginning of this how to for info).
First thing to do was to install one end of my new drop link to the strut, I don't have a picture of this but all it involved was popping the threaded stud on the drop link ball joint through the bracket on the strut from the inside out. Then screw on the nyloc nut and then tighten up to the recommended torque of 47 ft-lb using a 17mm spanner and 17mm socket. (I was able to use a spanner instead of a 5mm allen key on my new drop links because the ball joint itself had spanner flats instead of an allen key socket).
Before attempting to install the strut I needed to check that the top cup was still orientated correctly with the word OUT and arrow pointing towards the outside of the car with the hub mounting bracket lined up properly. Also the edge of the upper swivel part of the top mount that is cut in slightly has to face the rear of the car..see picture below. Although in this picture it needs to be rotated 90 degrees to line up.
Being careful not to move anything I then threaded the strut up into the wheel arch whilst lining up the 4 top mount studs with the holes in the strut tower.
I then propped the bottom of the strut against the lower suspension arm while I loosely fitted the 4 nuts at the top.
Next I fitted the bottom of the strut to the hub mounting lug, this needed the hub depressing slightly with body weight to get it low enough for the bracket to line up.
Then using my trolley jack handle as a makeshift lever to press down on the lower suspension arm I was able to fit the hub to strut mounting bolts.
Next job was to connect the bottom end of the new drop link to the ARB, and again tighten up to the recommended torque of 47 ft-lb. The strut to hub mounting bolts were tightened to the recommended torque of 188 ft-lb using a torque wrench and 19mm socket & spanner.
Then it was back to the top mount nuts and using a torque wrench and 14mm socket they were tightened to the recommended setting of 26 ft-lbs.
I then checked the torque of the piston rod top nut which should be tightened to 36ft-lbs..be careful to hold the strut top cup in place to prevent it turning..I used a set of molegrips to to clamp the edge and hold onto it while tightening with the torque wrench.
I then threaded the brake hose through the strut bracket and fitted a new bottom clip (sourced from Toyota for 88p part No.90468-08034) and then connected up the banjo bolt to the calliper with 2 new copper crush washers. I then bled the air out of the system using an easy bleeder kit and refitted the road wheel. I then went on to repeat the procedure for the passenger side.
I have taken the car out for a test drive and although I still have my ball joints and most of the high & tight bushes to fit, I can honestly say it has transformed the ride of the car totally. Gone are the rattles and bangs that were present previously and the overall drive is much much smoother. I have yet to really try it in anger but so far I'm impressed.
As for overall drop, Tein say the drop should be approx 35-38mm, but I measured the car beforehand and the back was 630mm to the inside edge of the wheel arch and the front was 640mm from flat level ground.
After drop my measurements are 610mm at the rear and 610mm at the front. This has confirmed my suspicions that my standard rear springs were seriously sagging, as were my fronts to a lesser degree. The front of my car has always appeared to sit higher than the back, so this has now been corrected which I am happy about.
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