Refurbishing the lower arm (wishbone) renewing changing bushes and ball joint

The lower arms have three attachments, the ball joint on the outboard edge, a cylindrical rubber bush at the front inboard and a metal tab bush on the rear inboard. Its possible to buy all three bushes   but the total price is not appreciably different from the unbranded replacement arms available out there. Replacing the arms is a relatively simple job but given my recent experience you should go for branded parts and if you compare those with the cost of refurbishment using branded parts then the argument just swings in favour of refurbishing. Especially if you have a good (genuine Ford) arm to start with. In any event I wanted to try this and see how difficult it could be. The following gives my experience. In general it was OK but I still believe there is a better way of dealing with the metal tab bracket. I would also say that it is essential to drill the old ball joint rivets accurately so as not to enlarge the holes.

Inboard rear mounting- metal tab bracket.

The bush consists of and outer thick metal bracket, inside and bonded to this is a nylon cylinder which in turn is bonded to the rubber matrix. The rubber itself is also bonded to an inner thin walled metal cylinder through which an arm extension of the wishbone will pass.

Bush. Note wishbone arm extn filling the inner cylinder. The bush contains two rubber bridges which should be vertical when fitted.

The bracket is pressed onto the the wishbone with its chamfered side uppermost (i.e. the same side as the ball joint) and in line with the arm itself. Note that the rubber core isn't solid but has two gaps. these gaps are positioned across the arm with the solid rubber "bridges" crossing the wishbone vertically.

Metal bracket bush as fitted, note tab is inline with the wishbone, the chamfered side matches the ball joint and the rubber bridges inside the bush cross the wishbone at 90 degrees.

There are some videos out there that make it seem a simple job to replace this type of  bush but naturally in the real world its not like that.The videos show the bush removed by pressing the arm extension out of the centre of the bush. According to these videos this is easily done by supporting the outer metal bracket on the press plates and pushing down on the arm extension in the centre to pop it out of the inner cylinder. The bush is replaced using hand pressure!

Attempting to press out the arm extension-the rubber simply deforms!

The trouble is that unless your bush is in very good condition and hasn't been fitted for long, then this will be impossible. Of course if the forgoing applies then you would not be needing to change the bracket anyway. The reason is that over time corrosion gradually bonds the arm firmly into the inner cylinder. At the same time deterioration in the rubber weakens it. This means that when the bush outer metal casing is supported in the press, and pressure applied to the end of the arm inside the inner metal sleeve, the rubber simply stretches before the metal/metal contact inside the inner sleeve can give. This could be avoided if there was a way of supporting the inner sleeve alone whilst the arm is pressed out of it, but its very thin walled, probably less than 1mm and recessed between the body of the wishbone and the metal of the bracket. There is only 4mm of space to get at it so  the usual, very thick metal press support plates can't access it to support it and the pressure is invariably taken on the outer metal ring.

Gap between body of the wishbone and the bracket. The inner metal sleeve is barely visible 4mm above the wishbone and access is blocked

I tried a variety of "clever" solutions- including using a bearing puller but nothing succeeded and in the end I was forced to cut the bush off the arm. This can be a very MESSY job and the following represents my best guess at the "right" way to approach this job. Firstly reserve the angle grinder for metal- don't try to cut the rubber with it or you will coat everything in a rain of sticky rubbery droplets that will be the devil to remove!
Use the cutting disc to cut through the bracket on each side, don't go deeper into the rubber.

Slicing through the bracket on each side

You can then tap the bracket with a mallet and it should drop off.

Using a mallet the outer cut bracket just cracks off.

This reveals the inner nylon sleeve that is bonded to the rubber core.

Bracket has been removed revealing the nylon sleeve inside, first mini hack cut through the nylon has been made..

Cut through the nylon sleeve using a mini hacksaw. Make a couple of cuts each side above the gaps in the rubber. You can then lever the nylon apart and slip a craft knife down inside to cut away at the rubber. Remove the sections of nylon sheath as they are freed and keep slicing with the knife to trim away excess rubber and get as close as you can to the inner metal sleeve. Eventually this will reduce the  rubber to a thin coating on the inner metal sleeve.  You can then cut through the metal sleeve with a Dremmel and cutting disc (or grinder) but be careful as you don't want to cut right through and into the wishbone.  The idea is to cut most of the way through then use a cold chisel hammered into the slot to split the remaining thickness. You can use a mini hacksaw for this but its not possible to saw along the sleeve because the body of the wishbone obstructs this direction so you will have to cut a longer path in a spiral round the sleeve.

The rubber is cut away in sections using a craft knife until its feasible to cut the inner cylinder with the cutting disc.

Once split through the inner sleeve could be loosened and pushed up the arm extension to remove it.

Sliding the remnants of the bracket up the arm- I did scratch the  arm to some extent but will file the burrs off before refitting the bracket.

The arm is smoothed before fitting the new bracket. The new bracket is itself a tight fit and will need a press to be fit it on.

New bush. Note that the tongue of the bracket isn't central on the cylinder. It also has a chamfered and a plain side. The chamfered side faces up when the wishbone is fitted. The two internal rubber bridges should be vertical.

Inboard front mounting- The forward bush

The forward bush has a more conventional structure- a rubber bush with a thicker inner sleeve through which the bolt will pass. The bush has unequal sides, the rear side being a smaller diameter than the front. It can be wound out using a bush extraction press and pull kit. This places a flat plate on the rear of the bush and a cup on the front. Passing a threaded studding through both allows the bush to be withdrawn into the cup. Its also a good idea to remove the rubber lip from the side that is to be pushed inwards as this will make extraction easier

Rear side of forward bush on wishbone

Front side of forward bush- entirely covered by the rubber rim of the bush.

The problem here is that the front face of the bush completely covers the metal of the wishbone so there is no space in which to place a pressure cup. This rubber needs to be trimmed off to allow access to the metal of the wishbone beneath. I used a junior hacksaw to cut 4 lines surrounding thr central tube and then cutting underneath parallel to the wishbone. The rubber could the be pulled off or trimmed with a knife.

Outside edge-Metal rim of the wishbone eye revealed.

Inside edge, rubber lip trimmed away

 I used a Draper "push and pull" kit to wind out the bush. Its a little more sophisticated than using a length of studding and a socket, but its basically the same system.

Using the Draper kit to wind out the bush.

The bush came out easily.

Bush removed

Removing the Ball joint

The ball joint was originally fixed into the wishbone by three large rivets. I don't think it was ever intended to be replaceable but ball joint kits are now available that replace the rivets by nuts and bolts. In order to fit these of course the rivets have to be removed. This is aided by indentations in the original rivet heads that indicate the rivet centres.

Original rivets securing worn ball joint. Not indentations in centres

There is no alternative but to drill out these rivets which I did by hand. However this is more complex, its not just a case of drilling the heads off as the rivets and heads are very firmly (almost welded) in place right through the wishbone. This means you have to drill right through. I completely failed to find any way of supporting and clamping the heavy wishbone onto my pillar drill so I had to do this by hand.  The shaft of the rivet is just over 8mm in diameter so I drilled into the rivet head initially using a 4mm drill and keeping everything as vertical as possible. 

Hand drilling (4mm) into the rivet top.

I could then swap to a wide flat cut drill to remove most of the rivet head so I could see the shaft but without removing much of the wishbone itself. I could then continue with the 4mm drill right through the rivet and follow that with a 6mm bit. It is absolutely essential that you drill vertically so you don't enlarge the holes in the wishbone as this will cause uncertainty in ball joint location. Its a tricky job, you might be able to clamp the wishbone in a vice and drill horizontally, or use a G clamp to secure it to the bench (You will need a wooden packer to raise it up so that it doesn't rock on either the rivet heads or base of the ball joint.  Eventually the rivet shaft is weakened and the rivet cancan be tapped out.

Rivet removed- its about 8mm in diameter.

Once all 4 rivets are removed the ball joint just slips out of its slot in the wishbone.

Slipping out the old ball joint

Rebuilding the Arm

Clean the arm and degrease it thoroughly. Its also a good idea to repaint but avoid getting paint inside the sockets.

Ball Joint

Ball joint replacement is straightforward and the new joint just slips into the slot and bolts in. Make sure you have inserted it the right way up! I inserted the bolts from above so that even if the nuts were to come off the bolts wouldn't drop out.

New ball joint from below

From above

Rubber Bush

The rubber bush is inserted by reversing the pull method above. Clean the arm recess thoroughly and make sure that any burrs are removed. I then greased the socket with corrosion block or rubber friendly grease before drawing the bush in. You need to insert it from the outside as space between the wishbone mounts is limited. Use a wide washer against the outside (wider) edge of the bush and place a shallow cup on the inside-there isn't room to use any of the cups from my press and pull set on the inside so I used a wide socket. You can then draw the bush in making sure that the inside edge pops cleanly through the tube and sits neatly around the socket circumference.

New bush in position

Bracket Mount

• The bracket has to be positioned correctly, the internal solid rubber bridges must run at 90 degrees across the wishbone and the bevelled edge of the bracket is on the upper side (same as the ball joint).  This is a tricky job as the fit is really tight. I still believe there is a trick to doing this but even Moog who supply these brackets were unable to give any clues as to how the brackets should be fitted. They do warn not to try warming the bracket though as this can cause the rubber to degenerate. I think chilling the arm would help if you can fit it into a freezer. The bracket itself is then pressed on in line with the wishbone.  I started by tapping the bracket onto the arm extension with a mallet  followed by pressing it on. I made no attempt to press only on the inner sleeve of the bush which is too narrow to rest on and probably too fragile to press on. Instead I used a broad ram head that covered the bracket completely pressing on the outer metal as well as the centre. I pressed on to within 4mm of the arm the position where I had found the old bracket. You can't actually press on any further because the ram contacts the end of the arm. You will however need a floor standing press for this as it wouldn't fit under my bench press and I had to take it to a local garage  and ask them to complete the job!