I have been meaning to reply to this thread on the method I use, but have been holding off until I got some pics. I don’t remove the wheels or the shocks and just remove the shackles and U-bolts. If you’re replacing shocks at the same time, it’s only one extra step to do them. I had already replaced my shocks previously with OME shocks, which are also used with the OME 40mm lift, so there is no shock replacement mentioned in this “How-to”. My philosophy is that the wheels normally do a great job of keeping the diffs off the ground, let ‘em do it. In this way, I can change all 4 springs on a Sierra or LJ in around 1 ½ hours. This method works for Spring Under Axle arrangements, but could be amended to work with SPOA. All information is provided for your consideration, and no guarantees are expressed. YOU are responsible for your own safety.
Tools required are 2 axle stands, a Bottle jack (preferred) or Trolley jack, 14mm socket, 17mm socket.
Step 1: Find a hard level surface to work on. If it is level, you can rely on the handbrake, but chocking will be more secure. If it has any sort of slope or uneveness, you will need to chock both the wheels on the axle you are not working on, on the front and back sides of the tyre.
2: Lock the front hubs, put the car in Lo range and apply the handbrake.
3: Loosen the following nuts one full turn while the vehicle is still sitting on the ground. You do this while the car is still firmly on the ground as they have spring lock washers and can be stubborn. You don’t want to be fighting them while their up on jack stands. The nut on the large bush bolt can be removed altogether.
4: Put the jack stands next the chassis at the point you are going to support it. (For the front axle, this will be as far forward on the flat part of the chassis rail behind the front springs. For the rear axle, it is as far rearward on the flat part of the chassis rail in front of the rear springs. Actual position will be slightly different for SWB, LWB, Ute or LJ). Extend the axle stand to be the height of the bottom chassis rail PLUS the estimated amount of lift PLUS one pin hole.
5: We’ll start on the rear axle for no reason other than you have to start somewhere. You could do the front first if you want. Raise the rear axle with the jack. I’m using a bottle jack, so I have to do one wheel at a time, but a Trolley jack could do the whole rear end in one go. When you have raised it enough to put the axle stands under the chassis, slide both the stands under the chassis.
6: When the axle is raised, the spring is in Compression. Depending on your calculations for axle stand height, you usually have enough droop in the spring to allow you to lower the wheels so they will sit on the ground. At this point the spring will be in Tension. You can now lower the wheel (or axle), but only go about halfway. At some point midway, the spring will be neutral. Remove the nuts, spring washers and sideplate for the shackle. At the neutral point, you will be able to remove the shackle. You might need to adjust the spring up or down to find the sweet spot, or assist the shackle pins with a hammer, but they should come out easiest with spring in neutral.
7: When you have removed the shackle, lower the wheel completely to the ground. Remove the 4 nuts on the U-bolts and remove the U-bolts. Swing/rotate the plate to one side (it will be held in the air by the shock absorber). As you remove the U-bolts and/or the bottom plate, support the shackle end of the spring as it will drop on you when you release the bottom plate. Lay the shackle end on the ground.
8: Remove the bolt going through the large bush end of the spring. Remove the spring from under the vehicle. Removing your first spring should have taken you about 15-20min.
9: Do the other spring on the rear axle in the same manner.
10: Get your new springs ready. The bushes and shackle pins need to be lightly lubricated to prevent binding. You only need a light smear of grease to do this. Excessive grease will retain dirt and accelerate wear of your pins and bushes. If you are using Polyurethane bushes, Moly grease is best. If your are retaining the original style Rubber bushes, use a GRR rubber grease or even Vaseline petroleum jelly. Moly or Chassis grease will attack Rubber bushes. Fit the bushes to the springs and slide the springs under the car.
11: Lift the large bush end of the spring up to the chassis, and fit the bolt. Put the spring washer and nut on but just nip up the nut at this stage. Bolt comes in from the outer side of the chassis and the nut and washer is on the inner side. Don’t fully torque it up.
12: Lift the shackle end of the spring and fit the shackle to the spring and chassis. Again, fit the shackle from the outer side and washers and nuts on the inside, but don’t fully torque the nuts up.
13: If your spring is of a much higher lift that the old ones (that’s why you’re fitting them I suppose!), the spring will still be hanging well below the spring seat. Use the bottle jack to raise the spring by compression up to the axle. Use a point on the spring that will not interfere with you rotating the bottom plate back into place. This is why I prefer using a Bottle jack in place of a Trolley jack. It’s much more compact and controllable for this step.
14: As you raise the spring, the centre bolt of the spring pack needs to locate into a hole in the axle spring seat. By having the handbrake on and in Low range, the axle shouldn’t have moved too far for this to occur, but you may need to give a gentle shove on the axle tube or tyre to seat the spring correctly. Put the U-bolts over the axle tube, ensuring that they sit properly over the bumpstop saddle and that the bumpstop if oriented vertically. Swing the bottom plate back into place. You might need to compress the shock to get the plate into position. Pass the U-bolt through the plate and put the washers and nuts on. As you tighten up the nuts, try to keep then even (ie same amount of thread on each nut).At this stage, you can fully torque the nuts up to the specified value between 45 and 70Nm.
Lower the jack.
15: Once you have done both springs and the both wheels are on the ground, you can fully torque up the shackles and large bush nuts. The nuts on the shackle are torqued to between 30 to 55Nm, and the nut on the large bush bolt is torqued to 45 to 70Nm. My preference on these is to set the torque wrench to a high point in that range, but not maximum. That is, about 45Nm for the shackles, and 65Nm for the U-bolts and large end bolt.
16: You are now halfway done! Repeat the same procedure for the front end.
17: Once both ends are done, go for a shakedown run around the block. Try some slalom stuff, and try and fit in a potholed section of road or some speed humps. Come back and re-check the torque figures for ALL nuts. After about 2 weeks of driving, but not more than 1000Km, re-check all torque figures on nuts again and you’ll be right.
