Defender suspension overhaul
SPEAKING of hard work, my muscles are still recovering from a job I did a couple of weeks ago. The vehicle was a 1995 Defender 90, and the job was to change every single suspension bush, the rear A-frame ball joint, springs and shock absorbers. That is a lot of work, especially if things start to go wrong. Most of the bushes are of the Metalastik type, with inner and outer steel tubes bonded together with rubber. If the securing bolt has rusted into the tube you find yourself attempting to cut through the bolt without damaging either the suspension component or its mounting bracket. This is seldom an easy task.
On this vehicle all the bolts came out with no trouble. If you are replacing the bolts with new ones, it saves a bit of time to fire up the angle grinder and lop off the threaded ends which protrudes beyond the nuts, as these will inevitably be badly rusted. To change the bushes you really need a hydraulic press. If you are planning to fit polyurethane bushes you will be able to get away with burning the centres out of the old bushes then cutting a slot in the outer tube and knocking it out with a chisel. Polyurethane bushes will go in with a G-clamp and a couple of steel plates. Metalastik bushes usually need pressing in unless you have a Bushwacka or similar tool. Polyurethane versus original bushes is one of those debates which seem to run on forever on Internet forums – my personal preference is for good quality original-type bushes, and that is what this particular customer wanted.
The vehicle still had a couple of problems to throw at me. The first concerned the front bushes on the rear radius arms. These consist of a steel triangle sandwiched by two large round rubber bushes with thick steel end plates. The bushes are bolted to a bracket on the chassis, with one of the round bushes passing through the large hole in the bracket. The bushes on this vehicle had deteriorated badly, and had deformed so that they were too large to pass through the hole. I have come across this one before and the quickest way out, I have found, is to cut the end plates in half and remove them. This relieves the pressure on the bushes, which can then be knocked through the chassis with a lump hammer. That is after you have removed the three securing nuts and bolts, which will have corroded to shapeless blobs: two are easy enough to access with a disc cutter, the third is tucked away out of reach and takes a little more perseverance.
With the lower rear radius arms rebushed and refitted, the last job was to tackle the upper A frame – bushes and ball joint. The bushes last well and I very seldom find myself having to change them, which is a good thing because the bolts and nuts are massive and not especially easy to get a large socket and spanner onto. With hindsight it might have been easier to remove the propshaft and exhaust system to give me more swing, but I persevered, sweating buckets and cursing Solihull’s designers, until I was able to remove the frame, joint and carrier in one piece. The two arms of the frame are secured to the joint and carrier with two long bolts and nuts. Normally when changing the balljoint I remove the two bolts and leave the arms on the vehicle. As it turned out, needing to replace the arm bushes was a blessing in disguise, because one of the long bolts was rusted solidly into the carrier. Heating it up made no difference and trying to press it out just bent it.
After struggling for far too long I gave up and fetched another carrier out of the scrap bin. This one had been binned because one of the two 8 mm bolts which attach the balljoint to the carrier had sheared off. I drilled out the broken bolt, then removed the old balljoint using the method I described a few months ago, running a bead of weld round the inside of the old joint casing to shrink it so that it just dropped out of the carrier. I was now on the home straight. With the vehicle back on its wheels it was just a question of settling it level on the suspension, then tightening all the suspension bolts so that the Metalastik bushes were locked in a neutral position. It is important not to tighten the bolts until the vehicle is sitting level, otherwise you run the risk of overstressing the bushes and breaking the bond between the centre tubes and the rubber inserts.
I headed home for a long soak in the bath, and the next morning I was pleasantly surprised to find that I could still move. I’m not too old for this game just yet. No need for the four-post lift just yet.