Ranger and BT-50 DIY Suspension Fitting Guide

By Brendan O'Keefe

If you plan on touring, towing, need more clearance or would just like a better driving and handling 4X4, then you’ll be wanting to upgrade its suspension, sooner rather than later, and there are plenty of aftermarket options available for the popular 4X4 makes and models. But what about fitting it yourself and saving a few dollars, dollars that could be better spent on buying a better quality suspension kit in the first place?

In this DIY series, we’re going to take a look at fitting new suspension to popular late-model 4X4s at home, on the ground and with a minimum of fuss. Or in other words, we’re going to pass on some of our model specific fitting tricks, to save you time and keep your frustration levels in check.

So let’s get the fine print out of the way!

Legal note:

This suspension fitment guide is based on what I consider to be an ideal way to fit suspension to the specific vehicle model this article is covering. It’s not necessarily the only way, nor should it be considered gospel. Suspension components are safety-critical items which must be fitted correctly, and they must be fitted by a person with an acceptable level of competence when it comes to working with vehicles and the tools used. If that isn’t you, then please have your vehicle’s new suspension fitted by a professional. No liability for issues arising from the incorrect installation of suspension components will be accepted by myself or the publishers of this article.  

Getting Started

1 – Patience Grasshopper

A suspension upgrade should be one of the last modifications that you make to your 4X4. You only want to select spring rates after you have all of the major accessories fitted and have a solid idea of the weight the new springs will need to deal with. If you do this arse about, you’ll end up having to upgrade the springs, again, after they’ve sagged. If you try getting tricky with it and fit higher rate springs than you need now, knowing that you’ll be adding a lot of accessories later, then you’ll end up with a high riding bag of poo, and compromise wheel alignment, ride quality and handling. So, fit all of your major (heavy) accessories and then work out what spring rates you need.

2 – Buy smart

Purchase a suspension kit that includes pre-assembled struts. Coils to suit modern IFS vehicles can have spring rates exceeding 1,000lb/in, and that is far too high for common DIY coil spring compressors, and that makes assembling them at home extremely dangerous. The struts should be assembled using either a hydraulic or Branick style coil spring compressor.

3 – Prepare and work smart

Mark the position of all wheel alignment eccentric bolts. This will help stop the alignment from moving too far out of spec if you loosen or remove the bolts during the assembly process.

Measure your trim heights before you start! It is recommended that trim height measurements are done from the centre of the wheel to the lip of the guard or factory flare. This keeps the measurement in line with the records kept by transport authorities and eliminates variance between wheel sizes. If the supplier requires the measurement from the bottom of the wheel, keep both on record.

Make sure you fill out all of the necessary paperwork for warranty! Many suppliers require you to record all measurements and part numbers for warranty purposes.

Do not fully tighten any pivoting bolts (e.g. control arm, lower strut bolt, shackle and fixed end pins) in the air. These must be fully tensioned to the manufacturer’s specs when the vehicle is lowered back down onto the ground.

4 – Check that you have all parts needed

For a full suspension upgrade for the Ranger or BT-50 you’ll want the following:

2 x pre-assembled front struts and coils

2 x rear shocks absorbers

2 x rear leaf springs

2 x greaseable shackles

2 x greaseable pins

1 x leaf spring bush kit

4 x high tensile u-bolts

1 x centre bearing spacer kit

Step by Step Guides

Front suspension fitted on the ground

This is the process that most people attempting to fit their own suspension would use at home, and it assumes that you aren’t lucky enough to have a hoist in the shed.

1. Measure trim heights.
2. Remove front bash plates to allow access to wheel alignment nuts.
3. Chock the rear wheels.
4. Mark wheel alignment eccentric bolts showing their current setting/position.
5. Jack up the front of vehicle.
6. Place jack stands under chassis allowing front suspension to be at full droop.
7. Remove wheel.
8. Loosen wheel alignment nuts so the bottom control arm can move freely.
9. Undo ABS line off upper control arm.
10. Remove circlip/split pin from upper balljoint.
11. Undo upper balljoint nut but leave on a few threads. This will prevent the spindle assembly from dropping too far when you undo the ball joint itself.
12. Separate the upper ball joint from the spindle by hitting the spindle with a hammer. Be careful not to hit the balljoint boot as this may damage the boot.
13. Undo and remove sway bar links.
14. Jack up lower control using a bottle or floor jack until the pressure is removed from the spindle/ball joint.
15. Undo upper ball joint nut and lift UCA out of the way.
16. Be careful to not let the spindle/lower control arm assembly drop too low at any stage of the install. This will cause the CV to dislocate from the diff. If it does dislocate, you will need to relocate the CV before refitting the suspension.
17. Undo the three top strut bolts.
18. When undoing the upper strut nuts, it’s a good idea to leave one nut on a couple of threads to prevent the strut from falling out unexpectedly when removing the lower bolt.
19. Remove lower strut bolt.
20. Remove strut assembly from vehicle. Adjust the height on the jack to gain more clearance if needed.
21. Fit new strut using the reverse of the above procedure.
22. The lower control arm and lower strut bolts must be fully tensioned on the ground and not in the air.

Rear suspension fitted on ground

1. Chock front wheels and then use a floor jack to lift the vehicle from the centre of the rear of the rear diff. Jack the vehicle high enough to fit your jack stands on their highest setting and then lower the floor jack until it just stops taking the weight off the diff and then remove the rear wheels.
2. Remove rear shock absorbers.
3. Undo the nut on the fixed end bolt but do not remove the nut.
4. Undo shackle nuts but do not remove the shackle, and then drop the spare tyre down enough to allow the shackle to be removed at step 8.
5. Undo u bolts on one side.
6. Lower the jack all of the way to give as much access as possible on the side with the u-bolts removed. Image shows wheels on but you’ll have a lot more success with the wheels off.
7. Remove the shackle.
8. Remove the fixed end bolt while ensuring the leaf spring is supported and can’t fall out.
9. With the help of another person, remove the leaf spring from the vehicle.
10. Grease new leaf spring bushes, shackles and fixed end bolts. When greasing the bushes, make sure you only grease the working parts of the bush. Then fit the new bushes into the new leaf springs.
11. Lift new leaf spring into place.
12. Fit fixed end bolt.
13. Fit shackle.
14. Jack the diff up so that the spring packs centre bolt head locates into its place on the axle housing. It may be necessary to move the wheel or diff assembly forward and back to help locate the centre bolt.
15. Fit new u bolts.
16. Repeat this process on the opposite side before re-fitting the wheels and lowering the vehicle back onto the ground, where you should now tighten the fixed end and shackle ends of both leaf packs.
17. Fit shocks and tighten and if supplied fit the centre bearing spacer kit per the manufacturer’s instructions.
18. Check that the spare tyre is back in position and then test drive the vehicle prior to re-checking the trim heights to establish exactly what has been achieved in this regard. If necessary, this is also the time to adjust the centre bearing spacer kit to remove (hopefully) any unwanted drivetrain shudder the lift may have introduced.
19. Take photos and post to Instagram.

Front Suspension fitted on a four-post hoist

If you are lucky enough to have a four-post hoist in the garage, there is another method for doing the front suspension that is easier and will save you some time. This method is completed from underneath the vehicle without needing to remove the wheel or undo the upper ball joint.

1. Measure trim heights.
2. Chock the rear wheels.
3. Raise hoist to access underneath the vehicle.
4. Remove front bash plates to allow access to wheel alignment nuts.
5. Mark wheel alignment eccentric bolts showing their current setting/position
6. Jack front suspension
7. Undo lower control arm eccentric alignment bolts and place bolts down in the direction that they face to help remember where they go.
8. Undo lower shock bolt.
9. Allow lower control arm to drop and move it out of the way.
10. Lower the hoist back down so you can access the top strut nuts.
    Undo the three top nuts while holding onto the strut and then carefully remove the strut.
11. Fit new strut and hold in place with one top strut nut.
12. Raise hoist again to access lower control bolts.
13. With the aid of a bottle jack, lift and position the lower control arm so the lower strut bolt and lower control arm eccentric bolts can be refitted.
14. Fit lower strut bolt and lower control arm eccentric bolts but leave them loose for now.
15. Lower front suspension so all weight is on the ground.
16. Tension lower strut bolt and lower control arm bolts to factory specification.
17. Refit bash plate.
18. Lower hoist to access top strut nuts.
19. Refit and tighten all top strut nuts.

Post fitment notes

A wheel alignment and headlight adjustment must be completed after the suspension is fitted. Many modern vehicles also require the steering angle sensor to be reset to suit the new height and alignment. All of this can be done by your local tyre shop.

Aftermarket control arms or offset/eccentric control arms bushes may be required to perfect the wheel alignment.

Re-tension and inspect all suspension components after 1,000km. Components like u-bolts will loosen as the spring pack settles in. It is also important to inspect the shock absorbers for any signs of leaking. If there is an issue with the seal on a shock absorber, it will normally be present after 1,000km of use.