stripping a Disco front hub/swivel replacment

[white90]

This has to be one of the dirtiest, oiliest, jobs you can do on any Land Rover - re-building the front hub.

Vehicle is a V8 Disco, not that it matters, as this is the same throughout the range - from a Series one downwards In this case, the swivel pins had worn, and as a result - a kind of chain reaction starts - excessive play caused by the pins wearing then causes the oil/swivel grease, to leak out of the housing - generally onto the inside tyre wall, and then around the wheel arch. As the level drops inside the housing - the top swivel bearing becomes starved of lubricant, and starts to break-up/ accellerate wear. The gap between the seal and swivel housing that lets oil out, now lets water in, and corrosion starts on expensive things such as CV joint and swivel housing. Symptoms of worn swivel pin bearings will be a clunk whenever you change direction. If you jack the wheel off the ground and try to rock it by grasping the wheel in the 12 and 6 o-clock position. If the wheel 'knocks' when you do this, then swivel pins are the culprit.

Having identified the problem, it's time to get down and dirty

First pic is what you might think is just one more oil leak, but in fact you are looking at around a hundred quid. You're gonna wish you did something about this sooner!

Jack up the vehicle and remove the road wheel, turn the steering hard left, and remove the 19mm nut and then washer that retains the steering drag link in the hub assembly. Use a ball joint removal tool, or strike the arm close to where the track rod end is with a hammer. After a few blows the joint will seperate.

On closer inspection you might see that the swivel housing is pitted/rusty. Trying to cut corners and still use the old one is a waste of time as the abrasive nature will quickly ruin the new seal, and far better to rebuild the hub assembly properly and know that it'll be ok for a few years to come.

You will need to methodically strip the entire hub right down to the end of the axle tube - so brake caliper, brake pipes, brake disc, driveshaft assembly, swivel housing, and 'chrome ball' will have to come off.

Caliper off first - held in place by two 12-point 13mm bolts. These will be very tight, so make sure the socket you use is a good fit. The upper bolt head in particular sits in a recess that can't be got at by usual methods. Tap the socket onto the bolt before attemting to undo it. There are two short steel brake pipes that go from the top of the swivel housing to the bottom of the caliper. They will have to be removed as they restrict access to the two upper swivel pin bolts. On this vehicle they were very rusty and one broke.

Remove the caliper and put it to one side. The two bolts are very similar to the 7 that hold the hub assembly to the axle, so keep them seperate.

The top swivel pin, and the bracket where the brake hoses are secured and connect to two steel pipes.

Drive flange next - prise off the rubber hub cap and the end of the driveshaft can be seen with a circlip and a few shims keeping it in position on the shaft. External circlip pliers and the clip and shims will come off.

Udo the 6x17mm bolts and the flange will come off.

Unforunately my camera is playing up, so I've lost about 3-pictures, but once the drive flange is removed you will be able to see the two nuts that keep the brake disc on the stub axle. Bend back the tab washer and remove the outer nut, then remove the tab washer and remove the second nut. DON't use a chisel/blunt screwdriver/Pair of long-nosed Mole grips to undo these nuts, considering the cost of the parts to do this job, the £7 cost of the correct box spanner is quite small.

Anyway, with the disc now off, you are left with the stub axle.

Next is the flimsy back plate. At the top it is hooked over a tab that is part of the brake pipe bracket, and then the steering lock stop nut, and by an M6 nut/bolt at the very bottom.

There's a drain plug (centre of picture) 11mm spanner will undo it to drain the remaining lubricant out of the swivel housing.

With the backplate out of the way, the drain plug can be removed. Nothing is left to drain out - not surprising really.

Remove these 6x17mm bolts in order to remove the stub axle.

Once undone, the stub axle and then the driveshaft unit can be removed.

Now to the rear of the swivel housing, and the seal, which is held in by a plate that has 6 x m8 bolts that have to be removed.

Camera failure again!

The bottom swivel pin is retained by two Torx bolts that also holds some odd kind of counterweight thing. The bolts are tight, so be careful when trying to undo them.

The top pin is held by two 17mm bolts, and once both pins have been removed, the housing assembly will come off. The two pin bearings are badly worn, the one on the right is the upper one, but the lack of grease and presence of water has caused damage to the lower one as well.

If by any chance your chrome ball is still ok, then you now need to remove the bearing tracks. Having the ball still bolted to the axle makes this a lot easier. A suitable drift and a hammer will get them out.

Finally down to the ball itself. This is held to the axle tube by 7 x 14mm 12-point bolts, and they are mental tight - in fact most people don't have enough veins in their forehead or knowledge of Anglo Saxon (well, except Bathtub ) No room for sockets here, so make sure the spanner is a very snug fit, and either use the method here to increase leverage, or some other way.

Using the two-spanner method is ok, but they must be kept in line - they can slip very easily otherwise.

Finally all is stripped down, and the end of the axle tube is all you should be able to see.

All the parts needed to do the job. Chrome ball is now a Teflon coated ball, it's seal that prevets swivel Lube from mixing with axle oil, swivel to axle gasket, Ball oil seal, swivel pins, shims, and pin bearings, plus tube of One Shot grease. About £120 from aftermarket supplier.

First thing - press or carefully drift the pin bearing tracks into the ball.

Then press the oil seal into the inboard end of the ball, making sure you put it in the right way round.

Stick a new gasket to the axle tube with grease, put the swivel seal on the ball - also making sure it's the right way round, then the seal retainer. The ball fixing holes are in a singular pattern, so it'll only go on the one way.

Use threadlock on the bolts and do them up really tight - they are all that's holding the entire front wheel assembly on the vehicle.

Take some time to clean all the bits that you are going to use again - there'll be plenty of grit around that could end-up where it's not wanted.

The swivel housing can now go on. Grease the previoulsy fitted bearing tracks, and place the upper bearing in place. The bottom one has to be placed where it'll eventually be held by the lower pin. Then 'hook' the lower bearing into it's seat and slide the top forward over the upper bearing. Place the top swivel pin in place and it'll stop it all from falling apart as soon as you let go.

The swivel pre-load has now to be set, which makes quite a difference to the steering feel of the vehicle if not done properly. A good rule of thumb is to use the same shims that I took off, and go from there. Out of the 6-that were on it originally, I ended-up removing 4. The driveshaft assembly can be re-fitted, new gasket, and then stub axle. The 6 x 17mm bolts need to be threadlocked as well.

Put a layer of grease on the new ball, then place the new seal in the housing - followed by the retainer and it's 8mm bolts. Note that the retainer will only go in one position. It's also worth mentioning that in severe cases, the main seal housing is badly corroded, which can let oil or grease out. If the corrosion is bad, then a thin bead of RTV sealant can be used.

Slide the disc assembly back on the stub axle, re-fit the two nuts using a new tab washer

When replacing the drive flange you might notice that the end of the drive shaft is inside the flange. Do up 4 bolts and use the fifth to pull the driveshaft out in order for the shims and then circlip to be re-fitted. The thread of the bolt is different from the thread in the hole, but you can 'hook' the thread to do this job, by pressing the bolt downwards as well as outwards. Once the circlip is on, fit the sixth bolt, apply some grease to the end of the shaft, and pop the hub cap back on. Replace the caliper and make sure that the two retaining bolts are very tight.

Finally - the two brake pipes that I broke are replaced by cupro-nickel ones and 4 x M10 fine male fittings.

Bleed the system using an assistant or an eezi-bleed system

Reconnect the steering drag link, and replace the road wheel.

Les.