How to Replace the Front Lower Suspension Wishbone Arms on a Discovery 3, 4, and Range Rover Sport

Hello and welcome to the Britpart workshop. We're here in Shropshire with Paul Myers, who is the MD of Britpart. Paul, tell us a bit about the company. We wholesale Land Rover parts around the world. So we ship parts for Land Rover vehicles from 1970 to brand new. Wow, and this site is absolutely enormous. How many people work it? We've got 300 people work on site, 55 acres of land and about half a million square foot of warehousing. Wow, and you're expanding all the time aren't you? Sure. Yes, yes. We've got plans at the moment to, put another warehouse up. That's great stuff. Okay. Today we're here fitting this component. What have we got here? This is a bottom arm of a Discovery three, Discovery four, or Range Rover Sport. Slight differences in the part numbers, but effectively the same item on all, all cars. Okay. And if you've got one of those vehicles and this component begins to fail, how would you know, how would you diagnose it? Two main causes of failure. This bush is called a hydro bush, it's actually full of oil. When that ruptures, it starts to move around too much and you get a clunking as a car goes backwards or forwards or hits a bump. And this ball joint will wear and a rattly sound on the outside of the suspension. Okay. And why not just replace the the bush or the ball joint? The bushes are very difficult to push out, and put back in, Okay. and we need a special tool to get the alignment right in the setting of the bush right. Otherwise the geometry of a car will never be correct. I see. Okay. Fair enough. So you've got this, that goes on the vehicles that you mentioned. You've also got these bolts. Is this a separate kit? Sure. The separate kit that we do includes all the bolts, and obviously the nuts and the washers to put the item back on the car. The reason that we do these, and recommend that you take these when you take the arm, is that the bolts actually seize into these holes and it's far easier to cut them out rather than try and push them out. I see. And you've got these offset washers. How do these work? What's the point of those? This is a camber washer, a camber bolt washer. and this works by as you turn the bolt you can actually set the geometry of a car. So there's a geometry of a relationship of a bush to the ball joint is very important. Yeah. I might address it on the bottom of the car. Brilliant. Okay. That's great. And of course, if there are any other wishbones which are worn on the vehicle you sell all those components too. Absolutely. The other high wear item on the suspension of these cars is a top rear wishbone. We do a full kit for that as well. Great stuff. Okay. So we're going to go over to the workshop now, we're going to go and see Steve and Martin and watch them fit one of these. See how they get on. Right. We've started by removing the plastic under tray that goes underneath the gearbox. That's to allow access to the nuts that hold back at the bottom arm on. We're going to start on the outside of the arm and move inwards to remove it, starting with the lower hub ball joint. On early vehicles it's sometimes necessary to undo the hub nut, and push the drive shaft through, which allows enough space for the hub ball joint to pass up and unhook itself when we've got everything else undone. So we're going to start by unbolting and removing the hub joint first. It's a 24 ml nut, so that needs to come off, and then we need to shock the joint apart which will then allow the arm to come off with everything else disconnected. So Steve's gonna. This is normally quite tight. Hopefully the joint won't crack before we've got the nut all the way off. This one appears to be cooperating. Steve hasn't removed the nut all the way. That's so that when he shocks the joint loose the hub doesn't drop out. So he's gonna give it a few whacks with a hammer to shock it loose. There we go. That's released. So the next job is to remove the bolt which holds the bottom of the strut to the lower arm. And if you look through our other videos you'll find there's a instructional video on how to replace the strut itself. They can sometimes fail if the bag's perished or it splits. So we've got a 24 ml nut on the back and I believe it's 21 ml headed bolt. Yeah. Once that's loosened, the bolt can be pushed out which will release the strut from the lower arm. It's nice and least we don't have to hit too hard. They're generally not too bad. Before we loosened the inner inboard bolts, you'll notice that they've got this strange shape around the bolt head and that's because they're cam bolts and what they do is set the geometry of the suspension. They adjust the caster and the camber on the vehicle. So it's really important to mark them before you remove them. To explain why alignment is so important, especially on a big vehicle like this, here's Fuzz with his top tip. This is my car. We've got a problem with these tires. This one has even wear across the whole of the surface. Whereas this one has wear on this outer surface. Now that has been caused by this wheel running slightly out of line. The vehicle tracking is incorrect. As it has been going along the outside of this tire has been scrubbing as the car has tried to carry on in a forward motion. Now, if we set the vehicle's wheels accurately we can get even tire wear at the front, on the steered axle, but also at the rear. It's important that we don't have the rear axle out of alignment, like so, because that then means that we have to compensate with the fronts to keep in a straight line. Which means that the body of the car, suddenly, is skew-whiff like so. So we align all the wheels on the car because it's vitally important that the relationship between the rears, and the fronts, and the left and the right, is exactly correct. So that we have accurate steering and controllability on the road. So the first thing we're going to do before we loosen and remove the inner bolts is Steve is going to mark the concentric washer, in relation to the chassis, so that when we put it back together, we're kind of roughly in the right place. He's just using a paint pen there, to make it really obvious when we put it all back together, that's going to be about right. Obviously it will have to go have an alignment done properly. He's marking it in two places to make sure that each bolt goes back in, in the right location, and also the right way round. The nuts and bolts that hold the arm to the chassis are really, really prone to corroding in place. And they won't release from the bush, no matter how much you hit them. And it's often the case that you'll have to get a hacksaw blade in between the arm and the chassis and cut through the original bolts in order to remove the arm. It's quite a painstaking and not much fun at all, but if it's the only way to get the arm off, then so be it. And obviously you'd you'd then transfer your paint marks to your new bolts before you fit them with the new arm. So the 24 ml spanner and 24 ml socket and a breaker bar and fingers crossed, these ones are going to come undone. Yeah, well the nuts come loose anyway, so that's half the battle. On this side you've got the catalytic converters in the way. So it's a bit of a pain to get on the nut on the rear most bush. So it's important to try and hold the nut with the spanner and then turn the bolt head, just to make life a little bit easier. Yeah. It looks like the bolts have broken free, so that's a bonus. If you do have to cut them off it's really important that you use a hacksaw blade, not an angle grinder. Because as you cut through the bolt, as there's tension from the chassis plate onto the arm itself, it will pinch the blade of the angle grinder, which can obviously cause it to snatch and cause all sorts of problems. So use a hacksaw blade either in a reciprocating saw or just by hand. So both the nuts are undone now and Steve can just tap the bolts. There he goes. We'll transfer the paint marks onto the new bolts when we fit the new arm. So it doesn't matter too much if he mushroomed the end over giving it a tap. Again, this one's a bit tricky for access because you've got the exhaust catalytic converters in the way. Makes life a little bit trickier. If you've got the luxury of air tools in your workshop, something like an air hammer can really help. So as soon as the washers lined up on the bolt, the pressure's released and the bolt will slide out. There's the washer. So now that everything's loose the long bolt can be removed from the bottom of the strut. We've depressurized this by putting the car in access mode before we lift it up. So there's not a lot of pressure, if any, in the airbag itself. From there the two inner bolts can be slid out of the chassis, like so. And then finally the ball joint nut can be spun off for the last few turns. The inner half of the arm can be brought down and then the arm should unhook from the hub. And the arm is free. Okay. So we've removed the old arm, Steve's unpackaged the new arm, and we're going to start by hooking the ball joint into its socket on the hub. Sometimes it can help to just pull the hub outward slightly, to expand the gap, and help the joint slot in more easily. Is that in? Yep. And he's going to just start the nut on the bottom of the thread there to make sure it doesn't go anywhere. Once that's in we can pull the hub out again, and slot the two bushes into their places on the chassis. So before we fit the hardware to that, Steve's going to transfer the paint marks we made on the old bolts onto the new ones, which will help us get the alignment as close as possible before we have it done at an alignment place. Again, because it's such a precise adjustment, you can get it pretty close with paint marks, but to make sure your tires don't wear unevenly, or anything like that, it's best to get it done professionally with laser laser alignment tools. He's also going to apply some copper grease to the shank and to the thread of the new bolt That's to prevent the problem that you may have come up against stripping your vehicle down, where they seize in place in the center of the bush. Once the bolts are prepared, they can be pushed through the bracket in the chassis and all the way through the bush. Cam washer slides onto the back of the new bolt, onto the two grooves in the bolt. You've then got just a normal washer before the nut goes on. And we're going to get both those bolts started loosely, and then we're going to set the ride height on the vehicle before they're torqued up. Hopefully you'd never have to replace these lower arms again, but just in case you need to take them off, for any other jobs on the car, greasing the bolts makes life a lot easier because you're not struggling for ages trying to cut them or, hammer them out. Again, with the rear bolt, the bolt pushes through from the front to the back of the car, you've then got the cam washer on the back, the normal washer, and then the 24 ml nut gets threaded on. Next up, we've got to line up the bottom of the strut with the socket in the lower arm. Steve's just using a bar to line up the holes. So you can push the bolt through with no problems. And what we're going to do, to make sure that the bushes aren't under any strain when we tighten the bolts, is we're going to use a pillar jack to raise the hub up so that it's up to ride height, a sort of normal height setting, torque the bolts, which will mean that when the vehicle's back down on the ground there's no additional stress put on the bushes and they won't wear out prematurely. Once that's tapped through, again 24 ml nut goes on the back. We're not going to tighten that one just yet either. Nut on the bottom of the hub ball joint can now be tightened. You may find that the joint tries to spin inside the hub as you tighten the nut. If that's the case, you can use a jack to apply a bit of pressure to the underside suspension arm, sorry the underside of the hub, which just sandwiches the taper, and makes it easier to tighten up. It doesn't need to be much pressure, it's just enough to hold that tapered joint tightly into the hub, so the nut can be tightened. What does the torque need to be on that nut Steve? 115? 115 Newton meters. Now that that joint's tight, Steve's going to reposition the jack, and we're going to raise the whole assembly up so that the suspension, the arm is set at normal ride height. And we'll torque the bushes. Because we've depressurized the air suspension system with the Britpart Lynx Evo, there's not enough pressure in the air bag to cause us a problem when we Jack the hub up. Obviously if you're doing this at home, it's really important to make sure that the air bag isn't pressurized as you jack up the corner of the car. Steve measured the ride height when the car was on the ground. So he's just measuring from the center of the drive shaft nut up to the top of the wheel arch to make sure it's correct for when we torque up the inner bushes and the strut bush. Now that the hub is set at ride height, Steve's going to adjust the cam bolts so that the new markings line up with the markings we made on the chassis, when we were disassembling. Let's try and get the alignment as close as possible. The torque setting on these arm to chassis bolts is 275 Newton meters, so obviously quite tight. Steve's using a digital torque wrench to torque these up. And the rear most one is quite difficult, because the catalytic converter is in the way, it's hard to get a torque wrench onto the nut. You can see the movement in the arm there, as Steve turns a cam bolt, and that's what sets the suspension geometry. As you can see, there's not much room at all to get a socket on the back of the bolt on the rear most arm bush. So what Steve's doing is just making sure the nut is on really, really tight. He's using the old double spanner method here. I'm sure most Land Rover owners will have used this in their time. So when he's satisfied that that's tight as it needs to be. So the last things tightened is the long bolt that passes through the bottom of the strut. I've got a new nut and bolt for that as well. Steve's winding the nut on now. And then that will be tightened up to 300 Newton meters, isn't it Steve? Yes it is. So pretty tight. Again, Steve's going to use the digital torque wrench for that, but any torque wrench that goes that high will be fine. Again, it's important for this bolt to be done up at ride height as well, so that the bush in the bottom of the damper isn't under stress. So that's the last bolt we needed to tighten. Now the suspension can be returned. Jack can be removed. And then the wheel and the under-tray can go back on and the vehicle can go to be aligned. So that's another job finished. For more handy tips on how to work on your Land Rover check out the other Britpart workshop videos.